WorldWideScience

Sample records for evoked brain activity

  1. Evoked Brain Activity and Personnel Performance

    Science.gov (United States)

    1987-10-01

    numt>er) performance assessment, biomagnetism , testing potential, magnetoencephalography, evoked potential, personnel...here. EF recordings were obtained using a DC SQUID Biomagnetic Detection System (B.T.I., Inc. model 600B, second derivative gradiometer). The single... Biomagnetism : Possible new predictor of personnel performance. (NPRDC Tech. Rep. 84-43). San Diego: Navy Personnel Research and Development Center

  2. 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.

  3. Associative learning in humans--conditioning of sensory-evoked brain activity.

    Science.gov (United States)

    Skrandies, W; Jedynak, A

    2000-01-01

    A classical conditioning paradigm was employed in two experiments performed on 35 human volunteers. In nine subjects, the presentation of Landolt rings (conditioned stimuli, CS + ) was paired with an electric stimulus (unconditioned stimuli, UCS) applied to the left median nerve. Neutral visual control stimuli were full circles (CS -) that were not paired with the UCS. The skin conductance response (SCR) was determined in a time interval of 5 s after onset of the visual stimuli, and it was measured in the acquisition and test phase. Associative learning was reflected by a SCR occurring selectively with CS +. The same experiment was repeated with another group of 26 adults while electroencephalogram (EEG) was recorded from 30 electrodes. For each subject, mean evoked potentials were computed. In 13 of the subjects, a conditioning paradigm was followed while the other subjects served as the control group (non-contingent stimulation). There were somatosensory and visual brain activity evoked by the stimuli. Conditioned components were identified by computing cross-correlation between evoked somatosensory components and the averaged EEG. In the visual evoked brain activity, three components with mean latencies of 105.4, 183.2, and 360.3 ms were analyzed. Somatosensory stimuli were followed by major components that occurred at mean latencies of 48.8, 132.5, 219.7, 294.8, and 374.2 ms latency after the shock. All components were analyzed in terms of latency, field strength, and topographic characteristics, and were compared between groups and experimental conditions. Both visual and somatosensory brain activity was significantly affected by classical conditioning. Our data illustrate how associative learning affects the topography of brain electrical activity elicited by presentation of conditioned visual stimuli.

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

    Science.gov (United States)

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

    2016-05-31

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

  5. Brain correlates of music-evoked emotions.

    Science.gov (United States)

    Koelsch, Stefan

    2014-03-01

    Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders.

  6. 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…

  7. Acute stress evokes sexually dimorphic, stressor-specific patterns of neural activation across multiple limbic brain regions in adult rats.

    Science.gov (United States)

    Sood, Ankit; Chaudhari, Karina; Vaidya, Vidita A

    2018-03-01

    Stress enhances the risk for psychiatric disorders such as anxiety and depression. Stress responses vary across sex and may underlie the heightened vulnerability to psychopathology in females. Here, we examined the influence of acute immobilization stress (AIS) and a two-day short-term forced swim stress (FS) on neural activation in multiple cortical and subcortical brain regions, implicated as targets of stress and in the regulation of neuroendocrine stress responses, in male and female rats using Fos as a neural activity marker. AIS evoked a sex-dependent pattern of neural activation within the cingulate and infralimbic subdivisions of the medial prefrontal cortex (mPFC), lateral septum (LS), habenula, and hippocampal subfields. The degree of neural activation in the mPFC, LS, and habenula was higher in males. Female rats exhibited reduced Fos positive cell numbers in the dentate gyrus hippocampal subfield, an effect not observed in males. We addressed whether the sexually dimorphic neural activation pattern noted following AIS was also observed with the short-term stress of FS. In the paraventricular nucleus of the hypothalamus and the amygdala, FS similar to AIS resulted in robust increases in neural activation in both sexes. The pattern of neural activation evoked by FS was distinct across sexes, with a heightened neural activation noted in the prelimbic mPFC subdivision and hippocampal subfields in females and differed from the pattern noted with AIS. This indicates that the sex differences in neural activation patterns observed within stress-responsive brain regions are dependent on the nature of stressor experience.

  8. Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI

    Science.gov (United States)

    Fox, Michael D.; Qian, Tianyi; Madsen, Joseph R.; Wang, Danhong; Li, Meiling; Ge, Manling; Zuo, Huan-cong; Groppe, David M.; Mehta, Ashesh D.; Hong, Bo; Liu, Hesheng

    2016-01-01

    Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20 years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach is demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility. PMID:26408860

  9. EEG Brain Wave Activity at Rest and during Evoked Attention in Children with Attention-Deficit/Hyperactivity Disorder and Effects of Methylphenidate.

    Science.gov (United States)

    Thomas, Bianca Lee; Viljoen, Margaretha

    2016-01-01

    The aim of this study was to assess baseline EEG brain wave activity in children with attention-deficit/hyperactivity disorder (ADHD) and to examine the effects of evoked attention and methylphenidate on this activity. Children with ADHD (n = 19) were tested while they were stimulant free and during a period in which they were on stimulant (methylphenidate) medication. Control subjects (n = 18) were tested once. EEG brain wave activity was tested both at baseline and during focussed attention. Attention was evoked and EEG brain wave activity was determined by means of the BioGraph Infiniti biofeedback apparatus. The main finding of this study was that control subjects and stimulant-free children with ADHD exhibited the expected reactivity in high alpha-wave activity (11-12 Hz) from baseline to focussed attention; however, methylphenidate appeared to abolish this reactivity. Methylphenidate attenuates the normal cortical response to a cognitive challenge. © 2016 S. Karger AG, Basel.

  10. Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI.

    Science.gov (United States)

    Fox, Michael D; Qian, Tianyi; Madsen, Joseph R; Wang, Danhong; Li, Meiling; Ge, Manling; Zuo, Huan-Cong; Groppe, David M; Mehta, Ashesh D; Hong, Bo; Liu, Hesheng

    2016-01-01

    Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach are demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility. Copyright © 2015. Published by Elsevier Inc.

  11. Two-day fasting evokes stress, but does not affect mood, brain activity, cognitive, psychomotor, and motor performance in overweight women.

    Science.gov (United States)

    Solianik, Rima; Sujeta, Artūras

    2018-02-15

    The physiological, cognitive state, and motor behavior changes that occur during acute fasting are not completely understood. Thus, the aim of this study was to estimate the effect of 2-day total fasting on evoked stress, mood, brain activity, and cognitive, psychomotor, and motor function in overweight women. Eleven overweight women (body mass index above 25kg/m 2 ) aged 20-30 years were tested under two conditions allocated randomly: 2-day zero-calorie diet with water provided ad libitum and 2-day usual diet. One week before the experiment, aerobic fitness was evaluated. Subjective stress ratings in relation to the diet, autonomic function, prefrontal cortex activity, cognitive performance, psychomotor coordination, and grip strength were evaluated before and after each diet. The study demonstrated that fasting decreased log-transformed high-frequency (HF) power, without affecting heart rate. The relative maximum oxygen uptake was negatively correlated with subjective stress rating and changes in log-transformed HF. Fasting did not affect mood, brain activity, and cognitive, motor, and psychomotor performance. Thus, 2-day total fasting evoked moderate stress with a shift of the autonomic nervous system balance toward sympathetic activity in overweight women. Better aerobic endurance is likely to facilitate the capacity for dealing with acute fasting. Regardless of the evoked stress, cognitive state and motor behavior remained intact. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Brain-immune interaction accompanying odor-evoked autobiographic memory.

    Science.gov (United States)

    Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

    2013-01-01

    The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

  13. Brain-immune interaction accompanying odor-evoked autobiographic memory.

    Directory of Open Access Journals (Sweden)

    Masahiro Matsunaga

    Full Text Available The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ, were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC and precuneus/posterior cingulate cortex (PCC were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

  14. Pain-Related Brain Activity Evoked by Active and Dynamic Arm Movement: Delayed-Onset Muscle Soreness as a Promising Model for Studying Movement-Related Pain in Humans.

    Science.gov (United States)

    Matsuda, Yoichi; Kan, Shigeyuki; Uematsu, Hironobu; Shibata, Masahiko; Fujino, Yuji

    2015-08-01

    To demonstrate delayed-onset muscle soreness (DOMS) is a suitable model for the study of movement-evoked pain, we attempted to identify brain regions specifically involved in pain evoked by active and dynamic movement under DOMS condition. Twelve healthy volunteers DOMS was induced in the left upper-arm flexor muscles by an eccentric elbow contraction exercise. Movement-evoked pain in the affected muscles was evaluated just before (day 0) and after (days 1-7 and 30) the exercise using a visual analog scale. Subjects underwent functional magnetic resonance imaging scans while performing repeated elbow flexion on day 2 (DOMS condition) and day 30 (painless condition). We compared brain activity between the DOMS and painless conditions. Movement-evoked pain reached peak intensity on day 2 and disappeared by day 30 in all subjects. No subject felt pain at rest on either of these days. Contralateral primary motor cortex (M1), parietal operculum and bilateral presupplementary motor area (pre-SMA) showed greater activity during active and dynamic arm movement with DOMS than during the same movement without pain. There was no difference in activation of brain regions known collectively as the "pain matrix," except for the parietal operculum, between the two conditions. Active and dynamic movement with pain selectively evoked activation of M1, pre-SMA, and parietal operculum, as assessed using DOMS. Our results demonstrate that DOMS is a promising experimental model for the study of movement-evoked pain in humans. 2015 The Authors Pain Medicine published by Wiley Periodicals, Inc. on behalf of American Academy of Pain Medicine.

  15. Inferring evoked brain connectivity through adaptive perturbation.

    Science.gov (United States)

    Lepage, Kyle Q; Ching, ShiNung; Kramer, Mark A

    2013-04-01

    Inference of functional networks-representing the statistical associations between time series recorded from multiple sensors-has found important applications in neuroscience. However, networksexhibiting time-locked activity between physically independent elements can bias functional connectivity estimates employing passive measurements. Here, a perturbative and adaptive method of inferring network connectivity based on measurement and stimulation-so called "evoked network connectivity" is introduced. This procedure, employing a recursive Bayesian update scheme, allows principled network stimulation given a current network estimate inferred from all previous stimulations and recordings. The method decouples stimulus and detector design from network inference and can be suitably applied to a wide range of clinical and basic neuroscience related problems. The proposed method demonstrates improved accuracy compared to network inference based on passive observation of node dynamics and an increased rate of convergence relative to network estimation employing a naïve stimulation strategy.

  16. Fast joint detection-estimation of evoked brain activity in event-related FMRI using a variational approach

    Science.gov (United States)

    Chaari, Lotfi; Vincent, Thomas; Forbes, Florence; Dojat, Michel; Ciuciu, Philippe

    2013-01-01

    In standard within-subject analyses of event-related fMRI data, two steps are usually performed separately: detection of brain activity and estimation of the hemodynamic response. Because these two steps are inherently linked, we adopt the so-called region-based Joint Detection-Estimation (JDE) framework that addresses this joint issue using a multivariate inference for detection and estimation. JDE is built by making use of a regional bilinear generative model of the BOLD response and constraining the parameter estimation by physiological priors using temporal and spatial information in a Markovian model. In contrast to previous works that use Markov Chain Monte Carlo (MCMC) techniques to sample the resulting intractable posterior distribution, we recast the JDE into a missing data framework and derive a Variational Expectation-Maximization (VEM) algorithm for its inference. A variational approximation is used to approximate the Markovian model in the unsupervised spatially adaptive JDE inference, which allows automatic fine-tuning of spatial regularization parameters. It provides a new algorithm that exhibits interesting properties in terms of estimation error and computational cost compared to the previously used MCMC-based approach. Experiments on artificial and real data show that VEM-JDE is robust to model mis-specification and provides computational gain while maintaining good performance in terms of activation detection and hemodynamic shape recovery. PMID:23096056

  17. 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.

  18. Motor Evoked Potentials of Trunk Muscles in Traumatic Brain Injury Patients

    OpenAIRE

    Seo, Min-Ho; Park, Sung-Hee; Ko, Myoung-Hwan; Seo, Jeong-Hwan

    2011-01-01

    Objective To evaluate the motor innervation of trunk muscles in traumatic brain injury patients. Method Twenty patients (12 men and 8 women) with traumatic brain injury were enrolled in this study. Their mean age was 41 years. Motor evoked potentials (MEPs) were performed on the motor cortex. Electromyographic activities were recorded from the bilateral rectus abdominis muscles, the external oblique abdominal muscles, and the 4th and 9th thoracic erector spinae muscles. The onset latency and ...

  19. Brain stem auditory evoked responses in human infants and adults

    Science.gov (United States)

    Hecox, K.; Galambos, R.

    1974-01-01

    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  20. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    OpenAIRE

    Oh, Seok-Kyun; Kim, Gwang-Won; Yang, Jong-Chul; Kim, Seok-Kwun; Kang, Heoung-Keun; Jeong, Gwang-Woo

    2012-01-01

    Objective This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. Materials and Methods A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with bot...

  1. Brain stem evoked response to forward and reversed speech in humans.

    Science.gov (United States)

    Galbraith, Gary C; Amaya, Elizabeth M; de Rivera, Jacinta M Diaz; Donan, Namee M; Duong, Mylien T; Hsu, Jeffrey N; Tran, Kim; Tsang, Lian P

    2004-09-15

    Speech stimuli played in reverse are perceived as unfamiliar and alien-sounding, even though phoneme duration and fundamental voicing frequency are preserved. Although language perception ultimately resides in the neocortex, the brain stem plays a vital role in processing auditory information, including speech. The present study measured brain stem frequency-following responses (FFR) evoked by forward and reverse speech stimuli recorded from electrodes oriented horizontally and vertically to measure signals with putative origins in auditory nerve and rostral brain stem, respectively. The vertical FFR showed increased amplitude due to forward speech. It is concluded that familiar phonological and prosodic properties of forward speech selectively activate central brain stem neurons.

  2. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seok Kyun; Kim, Gwang Won; Kang, Heoung Keun; Jeong, Gwang Woo [Chonnam National University, Gwangju (Korea, Republic of); Yang, Jong Chul [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Seok Kwun [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2012-06-15

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  3. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Oh, Seok-Kyun; Kim, Gwang-Won; Yang, Jong-Chul; Kim, Seok-Kwun; Kang, Heoung-Keun

    2012-01-01

    Objective This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. Materials and Methods A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. Results The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Conclusion Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males. PMID:22563262

  4. Dietary sodium deprivation evokes activation of brain regional neurons and down-regulation of angiotensin II type 1 receptor and angiotensin-convertion enzyme mRNA expression.

    Science.gov (United States)

    Lu, B; Yang, X J; Chen, K; Yang, D J; Yan, J Q

    2009-12-15

    Previous studies have indicated that the renin-angiotensin-aldosterone system (RAAS) is implicated in the induction of sodium appetite in rats and that different dietary sodium intakes influence the mRNA expression of central and peripheral RAAS components. To determine whether dietary sodium deprivation activates regional brain neurons related to sodium appetite, and changes their gene expression of RAAS components of rats, the present study examined the c-Fos expression after chronic exposure to low sodium diet, and determined the relationship between plasma and brain angiotensin I (ANG I), angiotensin II (ANG II) and aldosterone (ALD) levels and the sodium ingestive behavior variations, as well as the effects of prolonged dietary sodium deprivation on ANG II type 1 (AT1) and ANG II type 2 (AT2) receptors and angiotensin-convertion enzyme (ACE) mRNA levels in the involved brain regions using the method of real-time polymerase chain reaction (PCR). Results showed that the Fos immunoreactivity (Fos-ir) expression in forebrain areas such as subfornical organ (SFO), paraventricular hypothalamic nuclei (PVN), supraoptic nucleus (SON) and organum vasculosum laminae terminalis (OVLT) all increased significantly and that the levels of ANG I, ANG II and ALD also increased in plasma and forebrain in rats fed with low sodium diet. In contrast, AT1, ACE mRNA in PVN, SON and OVLT decreased significantly in dietary sodium depleted rats, while AT2 mRNA expression did not change in the examined areas. These results suggest that many brain areas are activated by increased levels of plasma and/or brain ANG II and ALD, which underlies the elevated preference for hypertonic salt solution after prolonged exposure to low sodium diet, and that the regional AT1 and ACE mRNA are down-regulated after dietary sodium deprivation, which may be mediated by increased ANG II in plasma and/or brain tissue.

  5. Mapping human brain networks with cortico-cortical evoked potentials

    Science.gov (United States)

    Keller, Corey J.; Honey, Christopher J.; Mégevand, Pierre; Entz, Laszlo; Ulbert, Istvan; Mehta, Ashesh D.

    2014-01-01

    The cerebral cortex forms a sheet of neurons organized into a network of interconnected modules that is highly expanded in humans and presumably enables our most refined sensory and cognitive abilities. The links of this network form a fundamental aspect of its organization, and a great deal of research is focusing on understanding how information flows within and between different regions. However, an often-overlooked element of this connectivity regards a causal, hierarchical structure of regions, whereby certain nodes of the cortical network may exert greater influence over the others. While this is difficult to ascertain non-invasively, patients undergoing invasive electrode monitoring for epilepsy provide a unique window into this aspect of cortical organization. In this review, we highlight the potential for cortico-cortical evoked potential (CCEP) mapping to directly measure neuronal propagation across large-scale brain networks with spatio-temporal resolution that is superior to traditional neuroimaging methods. We first introduce effective connectivity and discuss the mechanisms underlying CCEP generation. Next, we highlight how CCEP mapping has begun to provide insight into the neural basis of non-invasive imaging signals. Finally, we present a novel approach to perturbing and measuring brain network function during cognitive processing. The direct measurement of CCEPs in response to electrical stimulation represents a potentially powerful clinical and basic science tool for probing the large-scale networks of the human cerebral cortex. PMID:25180306

  6. Cortical evoked potential and extracellular K+ and H+ at critical levels of brain ischemia

    DEFF Research Database (Denmark)

    Astrup, J; Symon, L; Branston, N M

    1977-01-01

    As shown previously, the electrical function of the brain is critically dependent on cerebral blood flow in the sense that reduction beyond an ischemic threshold of approximately 15 ml/100 gm per minute (approximately 35% of control) in the baboon leads to complete failure of the somatosensory...... evoked response. This study tests the hypothesis that electrical failure in ischemia may be directly associated with a massive release of intracellular K+ or with a critical degree of extracellular acidosis. By microelectrode techniques, measurements of blood flow, extracellular activity of K+ and H...... local cerebral blood flow proportionally. Abolition of evoked response could not be explained by depolarization by release of intracellular K+, nor was it critically dependent on cortical pH. However, the massive release of intracellular K+ was by itself critically dependent on cortical blood flow...

  7. Steady-State Somatosensory Evoked Potential for Brain-Computer Interface–Present and Future

    Directory of Open Access Journals (Sweden)

    Sangtae eAhn

    2016-01-01

    Full Text Available Brain-computer interface (BCI performance has achieved continued improvement over recent decades, and sensorimotor rhythm-based BCIs that use motor function have been popular subjects of investigation. However, it remains problematic to introduce them to the public market because of their low reliability. As an alternative resolution to this issue, visual-based BCIs that use P300 or steady-state visually evoked potentials seem promising; however, the inherent visual fatigue that occurs with these BCIs may be unavoidable. For these reasons, steady-state somatosensory evoked potential (SSSEP BCIs, which are based on tactile selective attention, have gained increasing attention recently. These may reduce the fatigue induced by visual attention and overcome the low reliability of motor activity. In this literature survey, recent findings on SSSEP and its methodological uses in BCI are reviewed. Further, existing limitations of SSSEP BCI and potential future directions for the technique are discussed.

  8. Comparison of speech-evoked v tone-evoked P300 response: implications for predicting outcomes in patients with traumatic brain injury.

    Science.gov (United States)

    Lew, H L; Slimp, J; Price, R; Massagli, T L; Robinson, L R

    1999-01-01

    The P300 response is a cognitive event-related potential recorded over the scalp. The tone-evoked P300 response has been used to predict outcomes of patients with brain injury. However, it may lead to false predictions because some normal people have a very small tone-evoked P300 response. It is hypothesized that speech may generate a more robust P300 response than tones. A voice-generator prototype was designed for this study. The rare speech signal was the word "mommy" in a female voice. The common signal was a 1000-Hz tone. Twenty-two normal adults (11 males, 11 females; age range, 18-60 yr) were tested for both speech-evoked and tone-evoked P300 responses. Speech-evoked P300 responses had significantly larger amplitudes (mean, 12.1 microV) than the tone-evoked responses (mean, 5.9 microV; P < 0.0001). Six subjects with brain injury were also tested using the same protocol: two subjects with severe brain injury showed no response to either stimulus. Both died within 1 wk after the testing. Although two subjects with moderate brain injury could not complete the testing because of agitated behavior, two other subjects with mild traumatic brain injury showed a larger speech-evoked than tone-evoked P300 response. The speech-evoked P300 response may be promising in predicting outcomes of patients with brain injury.

  9. Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

    Science.gov (United States)

    Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

    2018-04-01

    Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

  10. Auditory Brain-Stem and Middle-and Long-Latency Evoked Potentials in Coma

    OpenAIRE

    Rosenberg, C; Wogensen, K; Starr, A

    1984-01-01

    Twenty-five patients in coma, each with a Glascow Coma Scale measure less than or equal to five, were studied within the first three days of hospitalization with auditory brain-stem and middle- and long-latency evoked potentials. Survival was related to the simultaneous preservation of long- and middle-latency and brain-stem evoked potentials. The preservation of just middle-latency and/or brain-stem components did not correlate with survival. However, if the group of patients in coma due to ...

  11. Motor evoked potentials of trunk muscles in traumatic brain injury patients.

    Science.gov (United States)

    Seo, Min-Ho; Park, Sung-Hee; Ko, Myoung-Hwan; Seo, Jeong-Hwan

    2011-08-01

    To evaluate the motor innervation of trunk muscles in traumatic brain injury patients. Twenty patients (12 men and 8 women) with traumatic brain injury were enrolled in this study. Their mean age was 41 years. Motor evoked potentials (MEPs) were performed on the motor cortex. Electromyographic activities were recorded from the bilateral rectus abdominis muscles, the external oblique abdominal muscles, and the 4th and 9th thoracic erector spinae muscles. The onset latency and amplitude of contralateral and ipsilateral MEPs were measured. All patients were assessed by the Korean version of the Berg Balance Scale (K-BBS) to investigate the relationship between the frequency of MEPs in trunk muscles and gait ability. The mean frequency of ipsilateral MEPs was 23.8% with more damaged hemisphere stimulation, while the contralateral MEPs showed a mean frequency of 47.5% with more damaged hemisphere stimulation in traumatic brain injury patients. The latencies and amplitudes of MEPs obtained from the more damaged hemisphere were not significantly different from those of the less damaged hemisphere. There was no correlation between the manifestation of MEPs in trunk muscles and gait ability. The ipsilateral and contralateral corticospinal pathways to trunk muscles are less likely to be activated in traumatic brain injury patients because of direct injury of the descending corticospinal motor tract or decreased excitability of the corticospinal tract from prefrontal contusion.

  12. Broad-Band Visually Evoked Potentials: Re(convolution in Brain-Computer Interfacing.

    Directory of Open Access Journals (Sweden)

    Jordy Thielen

    Full Text Available Brain-Computer Interfaces (BCIs allow users to control devices and communicate by using brain activity only. BCIs based on broad-band visual stimulation can outperform BCIs using other stimulation paradigms. Visual stimulation with pseudo-random bit-sequences evokes specific Broad-Band Visually Evoked Potentials (BBVEPs that can be reliably used in BCI for high-speed communication in speller applications. In this study, we report a novel paradigm for a BBVEP-based BCI that utilizes a generative framework to predict responses to broad-band stimulation sequences. In this study we designed a BBVEP-based BCI using modulated Gold codes to mark cells in a visual speller BCI. We defined a linear generative model that decomposes full responses into overlapping single-flash responses. These single-flash responses are used to predict responses to novel stimulation sequences, which in turn serve as templates for classification. The linear generative model explains on average 50% and up to 66% of the variance of responses to both seen and unseen sequences. In an online experiment, 12 participants tested a 6 × 6 matrix speller BCI. On average, an online accuracy of 86% was reached with trial lengths of 3.21 seconds. This corresponds to an Information Transfer Rate of 48 bits per minute (approximately 9 symbols per minute. This study indicates the potential to model and predict responses to broad-band stimulation. These predicted responses are proven to be well-suited as templates for a BBVEP-based BCI, thereby enabling communication and control by brain activity only.

  13. Evaluation of brain function in acute carbon monoxide poisoning with multimodality evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    He, Fengsheng; Liu, Xibao; Yang, Shi; Zhang, Shoulin (Institute of Occupational Medicine, Beijing (China)); Xu, Guanghua; Fang, Guangchai; Pan, Xiaowen (Navy Hospital, Beijing (China))

    1993-02-01

    The median nerve somatosensory evoked potentials (SEP), pattern reversal visual evoked potentials (VEP), and brain stem auditory evoked potentials (BAEP) were studied in 109 healthy adults and in 88 patients with acute carbon monoxide (CO) poisoning. The upper limits for normal values of peak and interpeak latencies of multimodalities of evoked potentials in the reference group were established by a stepwise multiple regression analysis. SEP changes selectively affecting N32 and N60 were found in 78.8% of patients. There was prolonged PI00 latency of VEP in 58.2% of the cases examined. The prevalence of BAEP abnormalities in comatose patients (36%) was significantly higher than that (8.6%) in conscious patients. BAEP abnormalities were most frequently seen in comatose patients who had diminished brain stem reflexes (77.8%). It has been found that a consistent abnormality involving N2O and subsequent peaks in SEP, a remarkable prolongation of PI00 latency in VEP, or a prolongation of Ill-V interpeak latency in BAEP as well as the reoccurrence of evoked potential abnormalities after initial recovery all indicate unfavorable outcomes in patients with acute CO poisoning. The multimodality evoked potentials have proved to be sensitive indicators in the evaluation of brain dysfunction and in the prediction of prognosis of acute CO poisoning and the development of delayed encephalopathy. 16 refs., 4 figs., 6 tabs.

  14. Do resting brain dynamics predict oddball evoked-potential?

    Directory of Open Access Journals (Sweden)

    Lee Tien-Wen

    2011-11-01

    Full Text Available Abstract Background The oddball paradigm is widely applied to the investigation of cognitive function in neuroscience and in neuropsychiatry. Whether cortical oscillation in the resting state can predict the elicited oddball event-related potential (ERP is still not clear. This study explored the relationship between resting electroencephalography (EEG and oddball ERPs. The regional powers of 18 electrodes across delta, theta, alpha and beta frequencies were correlated with the amplitude and latency of N1, P2, N2 and P3 components of oddball ERPs. A multivariate analysis based on partial least squares (PLS was applied to further examine the spatial pattern revealed by multiple correlations. Results Higher synchronization in the resting state, especially at the alpha spectrum, is associated with higher neural responsiveness and faster neural propagation, as indicated by the higher amplitude change of N1/N2 and shorter latency of P2. None of the resting quantitative EEG indices predict P3 latency and amplitude. The PLS analysis confirms that the resting cortical dynamics which explains N1/N2 amplitude and P2 latency does not show regional specificity, indicating a global property of the brain. Conclusions This study differs from previous approaches by relating dynamics in the resting state to neural responsiveness in the activation state. Our analyses suggest that the neural characteristics carried by resting brain dynamics modulate the earlier/automatic stage of target detection.

  15. Lifting the veil on the dynamics of neuronal activities evoked by transcranial magnetic stimulation

    Science.gov (United States)

    Li, Bingshuo; Virtanen, Juha P; Oeltermann, Axel; Schwarz, Cornelius; Giese, Martin A; Ziemann, Ulf

    2017-01-01

    Transcranial magnetic stimulation (TMS) is a widely used non-invasive tool to study and modulate human brain functions. However, TMS-evoked activity of individual neurons has remained largely inaccessible due to the large TMS-induced electromagnetic fields. Here, we present a general method providing direct in vivo electrophysiological access to TMS-evoked neuronal activity 0.8–1 ms after TMS onset. We translated human single-pulse TMS to rodents and unveiled time-grained evoked activities of motor cortex layer V neurons that show high-frequency spiking within the first 6 ms depending on TMS-induced current orientation and a multiphasic spike-rhythm alternating between excitation and inhibition in the 6–300 ms epoch, all of which can be linked to various human TMS responses recorded at the level of spinal cord and muscles. The advance here facilitates a new level of insight into the TMS-brain interaction that is vital for developing this non-invasive tool to purposefully explore and effectively treat the human brain. PMID:29165241

  16. Lifting the veil on the dynamics of neuronal activities evoked by transcranial magnetic stimulation.

    Science.gov (United States)

    Li, Bingshuo; Virtanen, Juha P; Oeltermann, Axel; Schwarz, Cornelius; Giese, Martin A; Ziemann, Ulf; Benali, Alia

    2017-11-22

    Transcranial magnetic stimulation (TMS) is a widely used non-invasive tool to study and modulate human brain functions. However, TMS-evoked activity of individual neurons has remained largely inaccessible due to the large TMS-induced electromagnetic fields. Here, we present a general method providing direct in vivo electrophysiological access to TMS-evoked neuronal activity 0.8-1 ms after TMS onset. We translated human single-pulse TMS to rodents and unveiled time-grained evoked activities of motor cortex layer V neurons that show high-frequency spiking within the first 6 ms depending on TMS-induced current orientation and a multiphasic spike-rhythm alternating between excitation and inhibition in the 6-300 ms epoch, all of which can be linked to various human TMS responses recorded at the level of spinal cord and muscles. The advance here facilitates a new level of insight into the TMS-brain interaction that is vital for developing this non-invasive tool to purposefully explore and effectively treat the human brain.

  17. Task-evoked brain functional magnetic susceptibility mapping by independent component analysis (χICA).

    Science.gov (United States)

    Chen, Zikuan; Calhoun, Vince D

    2016-03-01

    Conventionally, independent component analysis (ICA) is performed on an fMRI magnitude dataset to analyze brain functional mapping (AICA). By solving the inverse problem of fMRI, we can reconstruct the brain magnetic susceptibility (χ) functional states. Upon the reconstructed χ dataspace, we propose an ICA-based brain functional χ mapping method (χICA) to extract task-evoked brain functional map. A complex division algorithm is applied to a timeseries of fMRI phase images to extract temporal phase changes (relative to an OFF-state snapshot). A computed inverse MRI (CIMRI) model is used to reconstruct a 4D brain χ response dataset. χICA is implemented by applying a spatial InfoMax ICA algorithm to the reconstructed 4D χ dataspace. With finger-tapping experiments on a 7T system, the χICA-extracted χ-depicted functional map is similar to the SPM-inferred functional χ map by a spatial correlation of 0.67 ± 0.05. In comparison, the AICA-extracted magnitude-depicted map is correlated with the SPM magnitude map by 0.81 ± 0.05. The understanding of the inferiority of χICA to AICA for task-evoked functional map is an ongoing research topic. For task-evoked brain functional mapping, we compare the data-driven ICA method with the task-correlated SPM method. In particular, we compare χICA with AICA for extracting task-correlated timecourses and functional maps. χICA can extract a χ-depicted task-evoked brain functional map from a reconstructed χ dataspace without the knowledge about brain hemodynamic responses. The χICA-extracted brain functional χ map reveals a bidirectional BOLD response pattern that is unavailable (or different) from AICA. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Role of adrenal catecholamines in cerebrovasodilation evoked from brain stem

    International Nuclear Information System (INIS)

    Iadecola, C.; Lacombe, P.M.; Underwood, M.D.; Ishitsuka, T.; Reis, D.J.

    1987-01-01

    The authors studied whether adrenal medullary catecholamines (CAs) contribute to the metabolically linked increase in regional cerebral blood flow (rCBF) elicited by electrical stimulation of the dorsal medullary reticular formation (DMRF). Rats were anesthetized, paralyzed, and artificially ventilated. The DMRF was electrically stimulated with intermittent trains of pulses through microelectrodes stereotaxically implanted. Blood gases were controlled and, during stimulation, arterial pressure was maintained within the autoregulated range for rCBF. rCBF and blood-brain barrier (BBB) permeability were determined in homogenates of brain regions by using [ 14 C]iodoantipyrine and α-aminoisobutyric acid (AIB), respectively, as tracers. Plasma CAs (epinephrine and norepinephrine) were measured radioenzymatically. DMRF stimulation increased rCBF throughout the brain and elevated plasma CAs substantially. Acute bilateral adrenalectomy abolished the increase in plasma epinephrine, reduced the increases in flow in cerebral cortex, and abolished them elsewhere in brain. They conclude that the increases in rCBF elicited from the DMRF has two components, one dependent on, and the other independent of CAs. Since the BBB is impermeable to CAs and DMRF stimulation fails to open the BBB, the results suggest that DMRF stimulations allows, through a mechanism not yet determined, circulating CAs to act on brain and affect brain function

  19. [Forensic application of brainstem auditory evoked potential in patients with brain concussion].

    Science.gov (United States)

    Zheng, Xing-Bin; Li, Sheng-Yan; Huang, Si-Xing; Ma, Ke-Xin

    2008-12-01

    To investigate changes of brainstem auditory evoked potential (BAEP) in patients with brain concussion. Nineteen patients with brain concussion were studied with BAEP examination. The data was compared to the healthy persons reported in literatures. The abnormal rate of BAEP for patients with brain concussion was 89.5%. There was a statistically significant difference between the abnormal rate of patients and that of healthy persons (Pconcussion was 73.7%, indicating dysfunction of the brainstem in those patients. BAEP might be helpful in forensic diagnosis of brain concussion.

  20. Cerebral activation associated with visually evoked sexual arousal in the limbic system: functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Sung Jong; Kong, Gwang Woo; Kim, Hyung Joong; Seo, Jeong Jin; Kang, Heoung Keun; Cho, Ki Hyun; Yoon, Ka Hyun [School of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of); Kim, Kyung Yo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-08-01

    To identify the brain centers associated with visually evoked sexual arousal in the human brain, and to investigate the neural mechanism for sexual arousal using functional MRI (fMRI). A total of 20 sexually potent volunteers consisting of 10 males (mean age: 24) and 10 females (mean age: 23) underwent fMRI on a 1.5T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 slices (10 mm slice thickness) parallel to the AC-PC (anterior commissure and posterior commissure) line, giving a total of 511 MR images. The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 4-minute stimulation by an erotic video film, and concluded with a 2-minute rest. The brain activation maps and their quantification were analyzed by the statistical parametric mapping (SPM 99) program. The brain activation regions associated with visual sexual arousal in the limbic system are the posterior cingulate gyrus, parahippocampal gyrus, hypothalamus, medial cingulate gyrus, thalamus, amygdala, anterior cingulate gyrus, insula, hippocampus, caudate nucleus, globus pallidus and putamen. Especially, the parahippocampal gyrus, cingulate gyrus, thalamus and hypothalamus were highly activated in comparison with other areas. The overall activities of the limbic lobe, diencephalon, and basal ganglia were 11.8%, 10.5%, and 3.4%, respectively. In the correlation test between brain activity and sexual arousal, the hypothalamus and thalamus showed positive correlation, but the other brain areas showed no correlation. The fMRI is useful to quantitatively evaluate the cerebral activation associated with visually evoked, sexual arousal in the human brain. This result may be helpful by providing clinically valuable information on sexual disorder in humans as well as by increasing the understanding of the neuroanatomical correlates of sexual arousal.

  1. Cerebral activation associated with visually evoked sexual arousal in the limbic system: functional MR imaging

    International Nuclear Information System (INIS)

    Eun, Sung Jong; Kong, Gwang Woo; Kim, Hyung Joong; Seo, Jeong Jin; Kang, Heoung Keun; Cho, Ki Hyun; Yoon, Ka Hyun; Kim, Kyung Yo

    2004-01-01

    To identify the brain centers associated with visually evoked sexual arousal in the human brain, and to investigate the neural mechanism for sexual arousal using functional MRI (fMRI). A total of 20 sexually potent volunteers consisting of 10 males (mean age: 24) and 10 females (mean age: 23) underwent fMRI on a 1.5T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 slices (10 mm slice thickness) parallel to the AC-PC (anterior commissure and posterior commissure) line, giving a total of 511 MR images. The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 4-minute stimulation by an erotic video film, and concluded with a 2-minute rest. The brain activation maps and their quantification were analyzed by the statistical parametric mapping (SPM 99) program. The brain activation regions associated with visual sexual arousal in the limbic system are the posterior cingulate gyrus, parahippocampal gyrus, hypothalamus, medial cingulate gyrus, thalamus, amygdala, anterior cingulate gyrus, insula, hippocampus, caudate nucleus, globus pallidus and putamen. Especially, the parahippocampal gyrus, cingulate gyrus, thalamus and hypothalamus were highly activated in comparison with other areas. The overall activities of the limbic lobe, diencephalon, and basal ganglia were 11.8%, 10.5%, and 3.4%, respectively. In the correlation test between brain activity and sexual arousal, the hypothalamus and thalamus showed positive correlation, but the other brain areas showed no correlation. The fMRI is useful to quantitatively evaluate the cerebral activation associated with visually evoked, sexual arousal in the human brain. This result may be helpful by providing clinically valuable information on sexual disorder in humans as well as by increasing the understanding of the neuroanatomical correlates of sexual arousal

  2. Brain inflammation enhances 1-methyl-4-phenylpyridinium-evoked neurotoxicity in rats

    International Nuclear Information System (INIS)

    Goralski, Kerry B.; Renton, Kenneth W.

    2004-01-01

    Experimental Parkinson's disease and Parkinson's disease in humans include a CNS inflammatory component that may contribute to the pathogenesis of the disease. CNS inflammation produces a loss in cytochrome P450 metabolism and may impair the brain's protection against neurotoxins. We have examined if preexisting inflammation in the brain could increase the toxicity of the dopaminergic toxin 1-methyl-4-phenylpyridinium (MPP + ). Lipopolysaccharide (LPS, 25 μg) or saline (control) was injected into the left lateral cerebral ventricle. A single injection of MPP + into the median forebrain bundle followed 48 h later and produced a reduction in striatal dopamine content that was dose and time dependant. Two-days after 5 μg of MPP + was administered, a 90% decrease in striatal dopamine content was observed in saline- and LPS-pretreated rats. However, 4 and 7 days after 5 μg MPP + treatment, striatal dopamine recovered up to 70-80% of control values in saline-pretreated rats but remained depressed (80-90%) in rats treated with LPS. These results suggested that CNS inflammation might create an increased risk factor for drug-induced CNS toxicity or chemically mediated Parkinson's disease. The prolonged toxicity of MPP + may be due to a decrease in brain cytochrome P450 metabolism that occurs during inflammation. As a second objective for the study, we examined if the CNS lesion produced by MPP + altered cytochrome P450 metabolic activity in the liver, kidney, and lung. We have demonstrated a novel mechanism whereby the brain pathology produced by MPP + treatment contributes to a reduction in cytochrome P450 metabolism in the kidney but not the liver or lung. Therefore, a chemically evoked CNS disorder with a chronic inflammatory component might have major effects on the renal metabolism of drugs or endogenous substrates

  3. Predictive patterns of sensory evoked potentials in comatose brain injured patients evolving to brain death.

    Science.gov (United States)

    Scarpino, Maenia; Lanzo, Giovanni; Carrai, Riccardo; Lolli, Francesco; Migliaccio, Maria Luisa; Spalletti, Maddalena; Peris, Adriano; Amantini, Aldo; Grippo, Antonello

    2017-02-01

    To assess whether Somatosensory Evoked Potentials (SEPs), recorded within 24h after ICU admission, are reliable predictors of brain death (BD) in comatose patients with acquired brain injury of various aetiologies. SEPs were classified as absent (A), pathological (P), and normal (N). Considering SEP recordings from both hemispheres, 6 patterns were identified: NN, NP, PP, NA, AP, and AA. The final endpoint was BD. Of the 203 patients included in the study, 70 (34%) evolved toward BD. The survival analysis indicated that the combination of SEP patterns in a two-graded scale (grade 1: NN-NP-PP-NA, and grade 2: AP-AA), allowed for prediction of BD with the best accuracy. This aggregation predicted BD with a sensitivity of 75.7% (CI: 64-84), a specificity of 76.6% (CI: 68-83), a positive predictive value of 64.2% (CI: 53-74) and a negative predictive value of 84.3% (CI: 77-90) in overall patients, and with a sensitivity of 75.0% (CI: 63-84), a specificity of 84.9% (CI: 75-90), a positive predictive value of 77.5% (CI: 63-88) and a negative predictive value of 84.3% (CI: 74-91) when excluding cardiac arrest. It is worth including SEPs, in association with other investigations and clinical signs, in prognostic scores of BD. The early identification of patients at high risk of evolving towards BD could help physicians to optimise management. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. DEPRESSION OF THE PHOTIC AFTER DISCHARGE OF FLASH EVOKED POTENTIALS BY PHYSOSTIGMINE, CARBARYL AND PROPOXUR AND THE RELATIONSHIP TO INHIBITION OF BRAIN CHOLINESTERASE

    Science.gov (United States)

    The effects of N-methyl carbamate pesticides on the photic after discharge (PhAD) of flash evoked potentials (FEPs) and the relationship between inhibition of brain cholinesterase (ChE) activity and the PhAD were evaluated. FEPs were recorded in Long Evans rats treated with physo...

  5. Brain state-dependence of electrically evoked potentials monitored with head-mounted electronics.

    Science.gov (United States)

    Richardson, Andrew G; Fetz, Eberhard E

    2012-11-01

    Inferring changes in brain connectivity is critical to studies of learning-related plasticity and stimulus-induced conditioning of neural circuits. In addition, monitoring spontaneous fluctuations in connectivity can provide insight into information processing during different brain states. Here, we quantified state-dependent connectivity changes throughout the 24-h sleep-wake cycle in freely behaving monkeys. A novel, head-mounted electronic device was used to electrically stimulate at one site and record evoked potentials at other sites. Electrically evoked potentials (EEPs) revealed the connectivity pattern between several cortical sites and the basal forebrain. We quantified state-dependent changes in the EEPs. Cortico-cortical EEP amplitude increased during slow-wave sleep, compared to wakefulness, while basal-cortical EEP amplitude decreased. The results demonstrate the utility of using portable electronics to document state-dependent connectivity changes in freely behaving primates.

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

    Science.gov (United States)

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

    2016-08-01

    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 synchronization of the afferent nociceptive input. Additionally, mechanical punctate stimulation does not activate nociceptors exclusively. In contrast, low-intensity intraepidermal electrical stimulation (IES) allows selective activation of type II Aδ-mechano-heat nociceptors (II-AMHs) and elicits reproducible brain potentials. However, it is unclear whether hyperalgesia from IES occurs and coexists with secondary mechanical punctate hyperalgesia, and whether the magnitude of the electroencephalographic (EEG) responses evoked by IES within the hyperalgesic area is increased. To address these questions, we explored the modulation of the psychophysical and EEG responses to IES by intraepidermal injection of capsaicin in healthy human subjects. We obtained three main results. First, the intensity of the sensation elicited by IES was significantly increased in participants who developed robust mechanical punctate hyperalgesia after capsaicin injection (i.e., responders), indicating that hyperalgesia from IES coexists with punctate mechanical hyperalgesia. Second, the N2 peak magnitude of the EEG responses elicited by IES was significantly increased after the intraepidermal injection of capsaicin in responders only. Third, a receiver-operator characteristics analysis showed that the N2 peak amplitude is clearly predictive of the presence of CS. These findings suggest that the EEG responses elicited by IES reflect secondary hyperalgesia and therefore represent an objective correlate of CS. Copyright © 2016 the American Physiological Society.

  7. Neural connectivity in hand sensorimotor brain areas: an evaluation by evoked field morphology.

    Science.gov (United States)

    Tecchio, Franca; Zappasodi, Filippo; Pasqualetti, Patrizio; Rossini, Paolo Maria

    2005-02-01

    The connectivity pattern of the neural network devoted to sensory processing depends on the timing of relay recruitment from receptors to cortical areas. The aim of the present work was to uncover and quantify the way the cortical relay recruitment is reflected in the shape of the brain-evoked responses. We recorded the magnetic somatosensory evoked fields (SEF) generated in 36 volunteers by separate bilateral electrical stimulation of median nerve, thumb, and little fingers. After defining an index that quantifies the shape similarity of two SEF traces, we studied the morphologic characteristics of the recorded SEFs within the 20-ms time window that followed the impulse arrival at the primary sensory cortex. Based on our similarity criterion, the shape of the SEFs obtained stimulating the median nerve was observed to be more similar to the one obtained from the thumb (same median nerve innervation) than to the one obtained from the little finger (ulnar nerve innervation). In addition, SEF shapes associated with different brain regions were more similar within an individual than between subjects. Because the SEF morphologic characteristics turned out to be quite diverse among subjects, we defined similarity levels that allowed us to identify three main classes of SEF shapes in normalcy. We show evidence that the morphology of the evoked response describes the anatomo-functional connectivity pattern in the primary sensory areas. Our findings suggest the possible existence of a thalamo-cortico-thalamic responsiveness loop related to the different classes.

  8. Evoked itch perception is associated with changes in functional brain connectivity

    Directory of Open Access Journals (Sweden)

    Gaëlle Desbordes

    2015-01-01

    Full Text Available Chronic itch, a highly debilitating condition, has received relatively little attention in the neuroimaging literature. Recent studies suggest that brain regions supporting itch in chronic itch patients encompass sensorimotor and salience networks, and corticostriatal circuits involved in motor preparation for scratching. However, how these different brain areas interact with one another in the context of itch is still unknown. We acquired BOLD fMRI scans in 14 atopic dermatitis patients to investigate resting-state functional connectivity before and after allergen-induced itch exacerbated the clinical itch perception in these patients. A seed-based analysis revealed decreased functional connectivity from baseline resting state to the evoked-itch state between several itch-related brain regions, particularly the insular and cingulate cortices and basal ganglia, where decreased connectivity was significantly correlated with increased levels of perceived itch. In contrast, evoked itch increased connectivity between key nodes of the frontoparietal control network (superior parietal lobule and dorsolateral prefrontal cortex, where higher increase in connectivity was correlated with a lesser increase in perceived itch, suggesting that greater interaction between nodes of this executive attention network serves to limit itch sensation via enhanced top-down regulation. Overall, our results provide the first evidence of itch-dependent changes in functional connectivity across multiple brain regions.

  9. Steady State Visual Evoked Potential Based Brain-Computer Interface for Cognitive Assessment

    DEFF Research Database (Denmark)

    Westergren, Nicolai; Bendtsen, Rasmus L.; Kjær, Troels W.

    2016-01-01

    decline is important. Cognitive decline may be detected using fullyautomated computerized assessment. Such systems will provide inexpensive and widely available screenings of cognitive ability. The aim of this pilot study is to develop a real time steady state visual evoked potential (SSVEP) based brain......-computer interface (BCI) for neurological cognitive assessment. It is intended for use by patients who suffer from diseases impairing their motor skills, but are still able to control their gaze. Results are based on 11 healthy test subjects. The system performance have an average accuracy of 100% ± 0%. The test...

  10. Music evoked autobiographical memory after severe acquired brain injury: preliminary findings from a case series.

    Science.gov (United States)

    Baird, A; Samson, S

    2014-01-01

    Music evoked autobiographical memories (MEAMs) have been characterised in the healthy population, but not, to date, in patients with acquired brain injury (ABI). Our aim was to investigate music compared with verbal evoked autobiographical memories. Five patients with severe ABI and matched controls completed the experimental music (MEAM) task (a written questionnaire) while listening to 50 "Number 1 Songs of the Year" (from 1960 to 2010). Patients also completed the Autobiographical Memory Interview (AMI) and a standard neuropsychological assessment. With the exception of Case 5, who reported no MEAMs and no autobiographical incidents on the AMI and who also had impaired pitch perception, the range of frequency and type of MEAMs in patients was broadly in keeping with their matched controls. The relative preservation of MEAMs in four cases was particularly noteworthy given their impaired verbal and/or visual anterograde memory, and in three cases, autobiographical memory impairment. The majority of MEAMs in both cases and matched controls were of a person/people or a period of life. In three patients music was more efficient at evoking autobiographical memories than the AMI verbal prompts. This is the first study of MEAMs after ABI. The findings suggest that music is an effective stimulus for eliciting autobiographical memories, and may be beneficial in the rehabilitation of autobiographical amnesia, but only in patients without a fundamental deficit in autobiographical recall memory and intact pitch perception.

  11. [The central action of botulinum toxin type A assessed by brain auditory and somatosensory evoked potentials].

    Science.gov (United States)

    Sławek, Jarosław; Recławowicz, Daniel

    2004-01-01

    Botulinum toxin type A (BTX-A) acts as a neuromuscular blocker in the release of acetylcholine. Nevertheless, some clinical effects and side effects are difficult to explain only due to the peripheral mode of action. The aim of the study was to assess the central effects of BTX-A by measuring the two modalities of evoked potentials (somatosensory and brain-stem auditory). In 23 patients (13 females, 10 males, mean age of 46, range of 25-71) with idiopathic cervical dystonia (never treated with BTX-A) brainstem auditory evoked responses (BAER) and somatosensory evoked potentials from upper extremities (SEP) were performed before and 4-6 weeks after BTX-A administration. BTX-A (Botox in 14 patients, Dysport in 9 patients) was injected into neck muscles: sternocleidomastoideus, splenius capitis, trapezius and levator scapulae. The authors did not find any statistically significant differences in basic parameters (latency and interlatency of I, III, V in BAER and N9, N13, N20 and P25 responses in SEP) before and after BTX-A administration. It seems that BTX-A does not have any direct central effect or the methods are not sensitive enough to detect them. Remote (anatomically distant) clinical effects seen by other authors or side effects may be explained by indirect mechanism due to deafferentation of stimuli from muscle spindles after BTX-A injection and thus modifying the central loops of reflexes or due to unpredictable hematogenous spread of BTX-A to distant muscles.

  12. Steady state visual evoked potential (SSVEP based brain-computer interface (BCI performance under different perturbations.

    Directory of Open Access Journals (Sweden)

    Zafer İşcan

    Full Text Available Brain-computer interface (BCI paradigms are usually tested when environmental and biological artifacts are intentionally avoided. In this study, we deliberately introduced different perturbations in order to test the robustness of a steady state visual evoked potential (SSVEP based BCI. Specifically we investigated to what extent a drop in performance is related to the degraded quality of EEG signals or rather due to increased cognitive load. In the online tasks, subjects focused on one of the four circles and gave feedback on the correctness of the classification under four conditions randomized across subjects: Control (no perturbation, Speaking (counting loudly and repeatedly from one to ten, Thinking (mentally counting repeatedly from one to ten, and Listening (listening to verbal counting from one to ten. Decision tree, Naïve Bayes and K-Nearest Neighbor classifiers were used to evaluate the classification performance using features generated by canonical correlation analysis. During the online condition, Speaking and Thinking decreased moderately the mean classification accuracy compared to Control condition whereas there was no significant difference between Listening and Control conditions across subjects. The performances were sensitive to the classification method and to the perturbation conditions. We have not observed significant artifacts in EEG during perturbations in the frequency range of interest except in theta band. Therefore we concluded that the drop in the performance is likely to have a cognitive origin. During the Listening condition relative alpha power in a broad area including central and temporal regions primarily over the left hemisphere correlated negatively with the performance thus most likely indicating active suppression of the distracting presentation of the playback. This is the first study that systematically evaluates the effects of natural artifacts (i.e. mental, verbal and audio perturbations on SSVEP

  13. Steady state visual evoked potential (SSVEP) based brain-computer interface (BCI) performance under different perturbations.

    Science.gov (United States)

    İşcan, Zafer; Nikulin, Vadim V

    2018-01-01

    Brain-computer interface (BCI) paradigms are usually tested when environmental and biological artifacts are intentionally avoided. In this study, we deliberately introduced different perturbations in order to test the robustness of a steady state visual evoked potential (SSVEP) based BCI. Specifically we investigated to what extent a drop in performance is related to the degraded quality of EEG signals or rather due to increased cognitive load. In the online tasks, subjects focused on one of the four circles and gave feedback on the correctness of the classification under four conditions randomized across subjects: Control (no perturbation), Speaking (counting loudly and repeatedly from one to ten), Thinking (mentally counting repeatedly from one to ten), and Listening (listening to verbal counting from one to ten). Decision tree, Naïve Bayes and K-Nearest Neighbor classifiers were used to evaluate the classification performance using features generated by canonical correlation analysis. During the online condition, Speaking and Thinking decreased moderately the mean classification accuracy compared to Control condition whereas there was no significant difference between Listening and Control conditions across subjects. The performances were sensitive to the classification method and to the perturbation conditions. We have not observed significant artifacts in EEG during perturbations in the frequency range of interest except in theta band. Therefore we concluded that the drop in the performance is likely to have a cognitive origin. During the Listening condition relative alpha power in a broad area including central and temporal regions primarily over the left hemisphere correlated negatively with the performance thus most likely indicating active suppression of the distracting presentation of the playback. This is the first study that systematically evaluates the effects of natural artifacts (i.e. mental, verbal and audio perturbations) on SSVEP-based BCIs. The

  14. Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma - a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Lau, S.K.; Wei, W.I.; Sham, J.S.T.; Choy, D.T.K.; Hui, Y. (Queen Mary Hospital, Hong Kong (Hong Kong))

    1992-10-01

    A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway. (Author).

  15. Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma - a prospective study

    International Nuclear Information System (INIS)

    Lau, S.K.; Wei, W.I.; Sham, J.S.T.; Choy, D.T.K.; Hui, Y.

    1992-01-01

    A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway. (Author)

  16. Central Sensitization of Mechanical Nociceptive Pathways Is Associated with a Long-Lasting Increase of Pinprick-Evoked Brain Potentials.

    Science.gov (United States)

    van den Broeke, Emanuel N; Lambert, Julien; Huang, Gan; Mouraux, André

    2016-01-01

    Intense or sustained nociceptor activation, occurring, for example, after skin injury, can induce "central sensitization," i.e., an increased responsiveness of nociceptive neurons in the central nervous system. A hallmark of central sensitization is increased mechanical pinprick sensitivity in the area surrounding the injured skin. The aim of the present study was to identify changes in brain activity related to this increased pinprick sensitivity. In 20 healthy volunteers, increased pinprick sensitivity was induced using high frequency electrical stimulation of the forearm skin (HFS). Mechanical pinprick stimulation (64 and 90 mN) was used to elicit event-related brain potentials (ERPs). The recordings were performed before, 20 min after and 45 min after applying HFS. The contralateral non-sensitized arm served as control. Pinprick stimulation of 64 mN, but not 90 mN, applied in the area of increased pinprick sensitivity elicited a significant increase of a late-latency positive wave, between 300 and 1100 ms after stimulus onset and was maximal at midline posterior electrodes. Most importantly, this increase in EEG activity followed the time course of the increase in pinprick perception, both being present 20 and 45 min after applying HFS. Our results show that the central sensitization of mechanical nociceptive pathways, manifested behaviorally as increased pinprick sensitivity, is associated with a long-lasting increase in pinprick-evoked brain potentials provided that a 64 mN stimulation intensity is used.

  17. Serial recording of median nerve stimulated subcortical somatosensory evoked potentials (SEPs) in developing brain death.

    Science.gov (United States)

    Buchner, H; Ferbert, A; Hacke, W

    1988-01-01

    Subcortical somatosensory evoked potentials (SEPs) to median nerve stimulation were recorded serially in 35 patients during the evolution towards brain death and in brain death. Neuropathological alterations of the central nervous system down to the C1/C2 spinal cord segment in brain death are well known. SEP components supposed to be generated above this level should be lost in brain death, while components generated below should not be altered. Erb's point, scalp and neck potentials were recorded at C3/4, or over the spinous process C7, using an Fz reference. In 10 patients additional montages, including spinous process C2-Fz, a non-cephalic reference (Fz-contralateral shoulder) and a posterior to anterior neck montage (spinous process C7-jugulum) were used. The cephalic referenced N9 and N11 peaks remained unchanged until brain death. N9 and N11 decreased in parallel in amplitude and increased in latency after systemic effects like hypoxia or hypothermia occurred. The cephalic referenced 'N14' decreased in amplitude and increased in latency after the clinical brain death syndrome was observed, while N13 in the posterior to anterior neck montage remained unchanged. The alteration of 'N14' went parallel to the decrease of the P14 amplitude. The subcortical SEPs in the cephalic referenced lead are supposed to be a peak composed by a horizontally orientated dorsal horn generated N13 and a rostrally orientated P14 arising at the level of the foramen magnum. The deterioration of the non-cephalic referenced P14 and of its cephalic referenced reflection 'N14' seems to provide an additional objective criterion for the diagnosis of brain death.

  18. Electromagnetic imaging of dynamic brain activity

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-31

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

  19. Electromagnetic imaging of dynamic brain activity

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-01-01

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

  20. A method for reconstructing tomographic images of evoked neural activity with electrical impedance tomography using intracranial planar arrays.

    Science.gov (United States)

    Aristovich, Kirill Y; dos Santos, Gustavo Sato; Packham, Brett C; Holder, David S

    2014-06-01

    A method is presented for reconstructing images of fast neural evoked activity in rat cerebral cortex recorded with electrical impedance tomography (EIT) and a 6 × 5 mm(2) epicortical planar 30 electrode array. A finite element model of the rat brain and inverse solution with Tikhonov regularization were optimized in order to improve spatial resolution and accuracy. The optimized FEM mesh had 7 M tetrahedral elements, with finer resolution (0.05 mm) near the electrodes. A novel noise-based image processing technique based on t-test significance improved depth localization accuracy from 0.5 to 0.1 mm. With the improvements, a simulated perturbation 0.5 mm in diameter could be localized in a region 4 × 5 mm(2) under the centre of the array to a depth of 1.4 mm, thus covering all six layers of the cerebral cortex with an accuracy of brain hippocampal or thalamic activity could be localized with an accuracy of 0.5 mm with a 256 electrode array covering the brain. Parallel studies have achieved a temporal resolution of 2 ms for imaging fast neural activity by EIT during evoked activity; this encourages the view that fast neural EIT can now resolve the propagation of depolarization-related fast impedance changes in cerebral cortex and deeper in the brain with a resolution equal or greater to the dimension of a cortical column.

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

    Science.gov (United States)

    Raichle, Marcus E

    2015-05-19

    Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease.

  2. Brain volume analyses and somatosensory evoked potentials in multiple system atrophy.

    Science.gov (United States)

    Miyatake, Satoko; Mochizuki, Hitoshi; Naka, Tetsuji; Ugawa, Yoshikazu; Tanabe, Hajime; Kuzume, Daisuke; Suzuki, Mikiya; Ogata, Katsuhisa; Kawai, Mitsuru

    2010-03-01

    We investigated a progression of brain atrophy and somatosensory system dysfunction in multiple system atrophy (MSA). Subjects were 21 MSA patients [12 MSA-C (cerebellar type) and 9 MSA-P (parkinsonism type)]. The relative volumes of cerebrum, brainstem and cerebellum to the intracranial volume were obtained from three-dimensional computed tomography (3D-CT) of the brain. The median nerve somatosensory evoked potentials (SEPs) were recorded, and the latencies and amplitudes of N9, N11, P13/14, N20 and P25 components were measured. We studied correlations between brain volumes, SEP and clinical features. The brainstem and cerebellar atrophies were aggravated with progression of the disease. The central sensory conduction time (CSCT) was progressively prolonged in parallel with the disease duration irrespective of the actual age of the patients. In MSA patients, the volume reductions of cerebellum and brainstem could be one of structural markers of disease progression, and the sensory pathway is progressively involved with the progression of disease processes.

  3. Brain responses evoked by high-frequency repetitive transcranial magnetic stimulation: an event-related potential study

    NARCIS (Netherlands)

    Hamidi, M.; Slagter, H.A.; Tononi, G.; Postle, B.R.

    2010-01-01

    Background Many recent studies have used repetitive transcranial magnetic stimulation (rTMS) to study brain-behavior relationships. However, the pulse-to-pulse neural effects of rapid delivery of multiple TMS pulses are unknown largely because of TMS-evoked electrical artifacts limiting recording of

  4. Mapping cell-specific functional connections in the mouse brain using ChR2-evoked hemodynamics (Conference Presentation)

    Science.gov (United States)

    Bauer, Adam Q.; Kraft, Andrew; Baxter, Grant A.; Bruchas, Michael; Lee, Jin-Moo; Culver, Joseph P.

    2017-02-01

    Functional magnetic resonance imaging (fMRI) has transformed our understanding of the brain's functional organization. However, mapping subunits of a functional network using hemoglobin alone presents several disadvantages. Evoked and spontaneous hemodynamic fluctuations reflect ensemble activity from several populations of neurons making it difficult to discern excitatory vs inhibitory network activity. Still, blood-based methods of brain mapping remain powerful because hemoglobin provides endogenous contrast in all mammalian brains. To add greater specificity to hemoglobin assays, we integrated optical intrinsic signal(OIS) imaging with optogenetic stimulation to create an Opto-OIS mapping tool that combines the cell-specificity of optogenetics with label-free, hemoglobin imaging. Before mapping, titrated photostimuli determined which stimulus parameters elicited linear hemodynamic responses in the cortex. Optimized stimuli were then scanned over the left hemisphere to create a set of optogenetically-defined effective connectivity (Opto-EC) maps. For many sites investigated, Opto-EC maps exhibited higher spatial specificity than those determined using spontaneous hemodynamic fluctuations. For example, resting-state functional connectivity (RS-FC) patterns exhibited widespread ipsilateral connectivity while Opto-EC maps contained distinct short- and long-range constellations of ipsilateral connectivity. Further, RS-FC maps were usually symmetric about midline while Opto-EC maps displayed more heterogeneous contralateral homotopic connectivity. Both Opto-EC and RS-FC patterns were compared to mouse connectivity data from the Allen Institute. Unlike RS-FC maps, Thy1-based maps collected in awake, behaving mice closely recapitulated the connectivity structure derived using ex vivo anatomical tracer methods. Opto-OIS mapping could be a powerful tool for understanding cellular and molecular contributions to network dynamics and processing in the mouse brain.

  5. Cortical Activation Patterns Evoked by Temporally Asymmetric Sounds and Their Modulation by Learning.

    Science.gov (United States)

    Horikawa, Junsei; Ojima, Hisayuki

    2017-01-01

    When complex sounds are reversed in time, the original and reversed versions are perceived differently in spectral and temporal dimensions despite their identical duration and long-term spectrum-power profiles. Spatiotemporal activation patterns evoked by temporally asymmetric sound pairs demonstrate how the temporal envelope determines the readout of the spectrum. We examined the patterns of activation evoked by a temporally asymmetric sound pair in the primary auditory field (AI) of anesthetized guinea pigs and determined how discrimination training modified these patterns. Optical imaging using a voltage-sensitive dye revealed that a forward ramped-down natural sound (F) consistently evoked much stronger responses than its time-reversed, ramped-up counterpart (revF). The spatiotemporal maximum peak ( maxP ) of F-evoked activation was always greater than that of revF-evoked activation, and these maxP s were significantly separated within the AI. Although discrimination training did not affect the absolute magnitude of these maxP s, the revF-to-F ratio of the activation peaks calculated at the location where hemispheres were maximally activated (i.e., F-evoked maxP ) was significantly smaller in the trained group. The F-evoked activation propagated across the AI along the temporal axis to the ventroanterior belt field (VA), with the local activation peak within the VA being significantly larger in the trained than in the naïve group. These results suggest that the innate network is more responsive to natural sounds of ramped-down envelopes than their time-reversed, unnatural sounds. The VA belt field activation might play an important role in emotional learning of sounds through its connections with amygdala.

  6. Brain evoked potentials to noxious sural nerve stimulation in sciatalgic patients.

    Science.gov (United States)

    Willer, J C; De Broucker, T; Barranquero, A; Kahn, M F

    1987-07-01

    In sciatalgic patients and before any treatment, the goal of this work was to compare the amplitude of the late component (N150-P220) of the brain evoked potential (BEP) between resting pain-free conditions and a neurological induced pain produced by the Lasègue manoeuvre. The study was carried out with 8 inpatients affected with a unilateral sciatica resulting from an X-ray identified dorsal root compression from discal origin. The sural nerve was electrically stimulated at the ankle level while BEPs were recorded monopolarly from the vertex. The stimulus intensity eliciting a liminal nociceptive reflex response in a knee-flexor muscle associated with a liminal pain was selected for this study. Both normal and affected side were alternatively stimulated during several conditions of controls and of Lasègue's manoeuvres performed on the normal and on the affected side. Results show that the Lasègue manoeuvre performed on the affected side induced a significant increase in the amplitude of N150-P220; performed on the normal side, this same manoeuvre resulted in a significant decrease of the N150-P220 amplitude. These variations were observed whatever was the side (normal or affected) under sural nerve stimulation. The possible neural mechanisms of these changes and clinical implications of these data are then discussed.

  7. Recovery function of the human brain stem auditory-evoked potential.

    Science.gov (United States)

    Kevanishvili, Z; Lagidze, Z

    1979-01-01

    Amplitude reduction and peak latency prolongation were observed in the human brain stem auditory-evoked potential (BEP) with preceding (conditioning) stimulation. At a conditioning interval (CI) of 5 ms the alteration of BEP was greater than at a CI of 10 ms. At a CI of 10 ms the amplitudes of some BEP components (e.g. waves I and II) were more decreased than those of others (e.g. wave V), while the peak latency prolongation did not show any obvious component selectivity. At a CI of 5 ms, the extent of the amplitude decrement of individual BEP components differed less, while the increase in the peak latencies of the later components was greater than that of the earlier components. The alterations of the parameters of the test BEPs at both CIs are ascribed to the desynchronization of intrinsic neural events. The differential amplitude reduction at a CI of 10 ms is explained by the different durations of neural firings determining various effects of desynchronization upon the amplitudes of individual BEP components. The decrease in the extent of the component selectivity and the preferential increase in the peak latencies of the later BEP components observed at a CI of 5 ms are explained by the intensification of the mechanism of the relative refractory period.

  8. Sensory gating revisited: relation between brain oscillations and auditory evoked potentials in schizophrenia.

    Science.gov (United States)

    Brockhaus-Dumke, Anke; Mueller, Ralf; Faigle, Ulrich; Klosterkoetter, Joachim

    2008-02-01

    Disturbances of auditory information processing have repeatedly been shown in schizophrenia. To contribute to a better understanding of the neurophysiological underpinnings of habituation in auditory processing and its disturbance in schizophrenia we used three different approaches to analyze auditory evoked responses, namely phase-locking (PL) analyses, single trial amplitudes, and averaged event-related potentials (P50 and N100). Given that brain oscillations reflect the neuronal correlates of information processing we hypothesized that PL and amplitudes reflect even more essential parts of auditory processing than the averaged ERP responses. In 32 schizophrenia patients and 32 matched controls EEG was continuously recorded using an auditory paired click paradigm. PL of the lower frequency bands (alpha and theta) was significantly reduced in patients whereas no significant differences were present in higher frequencies (gamma and beta). Alpha and theta PL and amplitudes showed a marked increase after the first click and to a minor degree after the second one. This habituation was more prominent in controls whereas in schizophrenia patients the response to both clicks differed only slightly. N100 suppression was significantly reduced in schizophrenia patients whereas no group differences were present with respect to the P50. This corresponded to the finding that gamma mostly contributed to the prediction of the P50 response and theta mostly to the N100 response. Our data showed that analyzing phase and amplitude in single trials provides more information on auditory information processing and reflects differences between schizophrenia patients and controls better than analyzing the averaged ERP responses.

  9. Toward brain-computer interface based wheelchair control utilizing tactually-evoked event-related potentials

    Science.gov (United States)

    2014-01-01

    Background People with severe disabilities, e.g. due to neurodegenerative disease, depend on technology that allows for accurate wheelchair control. For those who cannot operate a wheelchair with a joystick, brain-computer interfaces (BCI) may offer a valuable option. Technology depending on visual or auditory input may not be feasible as these modalities are dedicated to processing of environmental stimuli (e.g. recognition of obstacles, ambient noise). Herein we thus validated the feasibility of a BCI based on tactually-evoked event-related potentials (ERP) for wheelchair control. Furthermore, we investigated use of a dynamic stopping method to improve speed of the tactile BCI system. Methods Positions of four tactile stimulators represented navigation directions (left thigh: move left; right thigh: move right; abdomen: move forward; lower neck: move backward) and N = 15 participants delivered navigation commands by focusing their attention on the desired tactile stimulus in an oddball-paradigm. Results Participants navigated a virtual wheelchair through a building and eleven participants successfully completed the task of reaching 4 checkpoints in the building. The virtual wheelchair was equipped with simulated shared-control sensors (collision avoidance), yet these sensors were rarely needed. Conclusion We conclude that most participants achieved tactile ERP-BCI control sufficient to reliably operate a wheelchair and dynamic stopping was of high value for tactile ERP classification. Finally, this paper discusses feasibility of tactile ERPs for BCI based wheelchair control. PMID:24428900

  10. A PET activation study of brush-evoked allodynia in patients with nerve injury pain

    DEFF Research Database (Denmark)

    Witting, Nanna; Kupers, Ron; Svensson, Peter

    2006-01-01

    during allodynic brushing. No thalamic activation was observed during allodynic or control brushing. Although no anterior cingulate cortex (ACC) activation could be demonstrated in the group analysis, single subject analysis revealed that four patients activated this region during brush-evoked allodynia...

  11. The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices

    OpenAIRE

    Bennett, Gillian C; Boarder, Michael R

    2000-01-01

    Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release.Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K+ in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxyl...

  12. Music-evoked emotions: principles, brain correlates, and implications for therapy.

    Science.gov (United States)

    Koelsch, Stefan

    2015-03-01

    This paper describes principles underlying the evocation of emotion with music: evaluation, resonance, memory, expectancy/tension, imagination, understanding, and social functions. Each of these principles includes several subprinciples, and the framework on music-evoked emotions emerging from these principles and subprinciples is supposed to provide a starting point for a systematic, coherent, and comprehensive theory on music-evoked emotions that considers both reception and production of music, as well as the relevance of emotion-evoking principles for music therapy. © 2015 New York Academy of Sciences.

  13. Laser speckle contrast reveals cerebral blood flow dynamics evoked by optogenetically controlled neuronal activity

    Science.gov (United States)

    Li, Nan; Thakor, Nitish V.; Pelled, Galit

    2013-03-01

    As a critical basis of functional brain imaging, neurovascular coupling describes the link between neuronal and hemodynamic changes. The majority of in vivo neurovascular coupling studies was performed by inducing sensory stimulation via afferent inputs. Unfortunately such an approach results in recruiting of multiple types of cells, which confounds the explanation of neuronal roles in stimulus evoked hemodynamic changes. Recently optogenetics has emerged to provide immediate control of neurons by exciting or inhibiting genetically engineered neurons expressing light sensitive proteins. However, there is a need for optical methods capable of imaging the concurrent hemodynamic changes. We utilize laser speckle contrast imaging (LSCI) to obtain high resolution display of cerebral blood flow (CBF) in the vicinity of the targeted neural population. LSCI is a minimally invasive method for imaging CBF in microvessels through thinned skull, and produces images with high spatiotemporal resolution, wide field of view. In the integrated system light sources with different wavelengths and band-passing/blocking filters were used to allow simultaneous optical manipulation of neuronal activities and optical imaging of corresponding CBF. Experimental studies were carried out in a rodent model expressing channalrhodopsin (ChR2) in excitatory neurons in the somatosensory cortex (S1). The results demonstrated significant increases of CBF in response to ChR2 stimulation (exciting neuronal firing) comparable to the CBF response to contralateral forepaw stimulation. The approach promises to be an exciting minimally invasive method to study neurovascular coupling. The complete system provides a novel approach for broad neuroscience applications.

  14. Human Cortical Activity Evoked by the Assignment of Authenticity when Viewing Works of Art

    Science.gov (United States)

    Huang, Mengfei; Bridge, Holly; Kemp, Martin J.; Parker, Andrew J.

    2011-01-01

    The expertise of others is a major social influence on our everyday decisions and actions. Many viewers of art, whether expert or naïve, are convinced that the full esthetic appreciation of an artwork depends upon the assurance that the work is genuine rather than fake. Rembrandt portraits provide an interesting image set for testing this idea, as there is a large number of them and recent scholarship has determined that quite a few fakes and copies exist. Use of this image set allowed us to separate the brain’s response to images of genuine and fake pictures from the brain’s response to external advice about the authenticity of the paintings. Using functional magnetic resonance imaging, viewing of artworks assigned as “copy,” rather than “authentic,” evoked stronger responses in frontopolar cortex (FPC), and right precuneus, regardless of whether the portrait was actually genuine. Advice about authenticity had no direct effect on the cortical visual areas responsive to the paintings, but there was a significant psycho-physiological interaction between the FPC and the lateral occipital area, which suggests that these visual areas may be modulated by FPC. We propose that the activation of brain networks rather than a single cortical area in this paradigm supports the art scholars’ view that esthetic judgments are multi-faceted and multi-dimensional in nature. PMID:22164139

  15. Simultaneously-evoked auditory potentials (SEAP): A new method for concurrent measurement of cortical and subcortical auditory-evoked activity.

    Science.gov (United States)

    Slugocki, Christopher; Bosnyak, Daniel; Trainor, Laurel J

    2017-03-01

    Recent electrophysiological work has evinced a capacity for plasticity in subcortical auditory nuclei in human listeners. Similar plastic effects have been measured in cortically-generated auditory potentials but it is unclear how the two interact. Here we present Simultaneously-Evoked Auditory Potentials (SEAP), a method designed to concurrently elicit electrophysiological brain potentials from inferior colliculus, thalamus, and primary and secondary auditory cortices. Twenty-six normal-hearing adult subjects (mean 19.26 years, 9 male) were exposed to 2400 monaural (right-ear) presentations of a specially-designed stimulus which consisted of a pure-tone carrier (500 or 600 Hz) that had been amplitude-modulated at the sum of 37 and 81 Hz (depth 100%). Presentation followed an oddball paradigm wherein the pure-tone carrier was set to 500 Hz for 85% of presentations and pseudo-randomly changed to 600 Hz for the remaining 15% of presentations. Single-channel electroencephalographic data were recorded from each subject using a vertical montage referenced to the right earlobe. We show that SEAP elicits a 500 Hz frequency-following response (FFR; generated in inferior colliculus), 80 (subcortical) and 40 (primary auditory cortex) Hz auditory steady-state responses (ASSRs), mismatch negativity (MMN) and P3a (when there is an occasional change in carrier frequency; secondary auditory cortex) in addition to the obligatory N1-P2 complex (secondary auditory cortex). Analyses showed that subcortical and cortical processes are linked as (i) the latency of the FFR predicts the phase delay of the 40 Hz steady-state response, (ii) the phase delays of the 40 and 80 Hz steady-state responses are correlated, and (iii) the fidelity of the FFR predicts the latency of the N1 component. The SEAP method offers a new approach for measuring the dynamic encoding of acoustic features at multiple levels of the auditory pathway. As such, SEAP is a promising tool with which to study how

  16. The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices.

    Science.gov (United States)

    Bennett, G C; Boarder, M R

    2000-10-01

    Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release. Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K(+) in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (0.2 mM). High K(+) substantially increased efflux of glutamate from the slices. Basal glutamate release was unchanged by the presence of nucleotides or adenosine at concentrations of 300 microM. Adenosine, ATP, ADP and adenosine 5'-O-(3-thiotriphoshate) at 300 microM attenuated depolarisation-evoked release of glutamate. However UTP, 2-methylthio ATP, 2-methylthio ADP, and alpha,beta-methylene ATP at 300 microM had no effect on stimulated glutamate efflux. Adenosine deaminase blocked the effect of adenosine, but left the response to ATP unchanged. The A(1) antagonist 8-cyclopentyl-1, 3-dipropylxanthine antagonised the inhibitory effect of both adenosine and ATP. Cibacron blue 3GA inhibited stimulus-evoked glutamate release when applied alone. When cibacron blue 3GA was present with ATP, stimulus-evoked glutamate release was almost eliminated. However, this P2 antagonist had no effect on the inhibition by adenosine. These results show that the release of glutamate from depolarised nerve terminals of the rat cerebral cortex is inhibited by adenosine and ATP. ATP appears to act directly and not through conversion to adenosine.

  17. Early and late activity in somatosensory cortex reflects changes in bodily self-consciousness: an evoked potential study.

    Science.gov (United States)

    Aspell, J E; Palluel, E; Blanke, O

    2012-08-02

    How can we investigate the brain mechanisms underlying self-consciousness? Recent behavioural studies on multisensory bodily perception have shown that multisensory conflicts can alter bodily self-consciousness such as in the "full body illusion" (FBI) in which changes in self-identification with a virtual body and tactile perception are induced. Here we investigated whether experimental changes in self-identification during the FBI are accompanied by activity changes in somatosensory cortex by recording somatosensory-evoked potentials (SEPs). To modulate self-identification, participants were filmed by a video camera from behind while their backs were stroked, either synchronously (illusion condition) or asynchronously (control condition) with respect to the stroking seen on their virtual body. Tibial nerve SEPs were recorded during the FBI and analysed using evoked potential (EP) mapping. Tactile mislocalisation was measured using the crossmodal congruency task. SEP mapping revealed five sequential periods of brain activation during the FBI, of which two differed between the illusion condition and the control condition. Activation at 30-50 ms (corresponding to the P40 component) in primary somatosensory cortex was stronger in the illusion condition. A later activation at ∼110-200 ms, likely originating in higher-tier somatosensory regions in parietal cortex, was stronger and lasted longer in the control condition. These data show that changes in bodily self-consciousness modulate activity in primary and higher-tier somatosensory cortex at two distinct processing steps. We argue that early modulations of primary somatosensory cortex may be a consequence of (1) multisensory integration of synchronous vs. asynchronous visuo-tactile stimuli and/or (2) differences in spatial attention (to near or far space) between the conditions. The later activation in higher-tier parietal cortex (and potentially other regions in temporo-parietal and frontal cortex) likely

  18. A Brain Computer Interface for Robust Wheelchair Control Application Based on Pseudorandom Code Modulated Visual Evoked Potential

    DEFF Research Database (Denmark)

    Mohebbi, Ali; Engelsholm, Signe K.D.; Puthusserypady, Sadasivan

    2015-01-01

    In this pilot study, a novel and minimalistic Brain Computer Interface (BCI) based wheelchair control application was developed. The system was based on pseudorandom code modulated Visual Evoked Potentials (c-VEPs). The visual stimuli in the scheme were generated based on the Gold code......, and the VEPs were recognized and classified using subject-specific algorithms. The system provided the ability of controlling a wheelchair model (LEGO R MINDSTORM R EV3 robot) in 4 different directions based on the elicited c-VEPs. Ten healthy subjects were evaluated in testing the system where an average...

  19. Endogenous sequential cortical activity evoked by visual stimuli.

    Science.gov (United States)

    Carrillo-Reid, Luis; Miller, Jae-Eun Kang; Hamm, Jordan P; Jackson, Jesse; Yuste, Rafael

    2015-06-10

    Although the functional properties of individual neurons in primary visual cortex have been studied intensely, little is known about how neuronal groups could encode changing visual stimuli using temporal activity patterns. To explore this, we used in vivo two-photon calcium imaging to record the activity of neuronal populations in primary visual cortex of awake mice in the presence and absence of visual stimulation. Multidimensional analysis of the network activity allowed us to identify neuronal ensembles defined as groups of cells firing in synchrony. These synchronous groups of neurons were themselves activated in sequential temporal patterns, which repeated at much higher proportions than chance and were triggered by specific visual stimuli such as natural visual scenes. Interestingly, sequential patterns were also present in recordings of spontaneous activity without any sensory stimulation and were accompanied by precise firing sequences at the single-cell level. Moreover, intrinsic dynamics could be used to predict the occurrence of future neuronal ensembles. Our data demonstrate that visual stimuli recruit similar sequential patterns to the ones observed spontaneously, consistent with the hypothesis that already existing Hebbian cell assemblies firing in predefined temporal sequences could be the microcircuit substrate that encodes visual percepts changing in time. Copyright © 2015 Carrillo-Reid et al.

  20. Conventional and cross-correlation brain-stem auditory evoked responses in the white leghorn chick: rate manipulations

    Science.gov (United States)

    Burkard, R.; Jones, S.; Jones, T.

    1994-01-01

    Rate-dependent changes in the chick brain-stem auditory evoked response (BAER) using conventional averaging and a cross-correlation technique were investigated. Five 15- to 19-day-old white leghorn chicks were anesthetized with Chloropent. In each chick, the left ear was acoustically stimulated. Electrical pulses of 0.1-ms duration were shaped, attenuated, and passed through a current driver to an Etymotic ER-2 which was sealed in the ear canal. Electrical activity from stainless-steel electrodes was amplified, filtered (300-3000 Hz) and digitized at 20 kHz. Click levels included 70 and 90 dB peSPL. In each animal, conventional BAERs were obtained at rates ranging from 5 to 90 Hz. BAERs were also obtained using a cross-correlation technique involving pseudorandom pulse sequences called maximum length sequences (MLSs). The minimum time between pulses, called the minimum pulse interval (MPI), ranged from 0.5 to 6 ms. Two BAERs were obtained for each condition. Dependent variables included the latency and amplitude of the cochlear microphonic (CM), wave 2 and wave 3. BAERs were observed in all chicks, for all level by rate combinations for both conventional and MLS BAERs. There was no effect of click level or rate on the latency of the CM. The latency of waves 2 and 3 increased with decreasing click level and increasing rate. CM amplitude decreased with decreasing click level, but was not influenced by click rate for the 70 dB peSPL condition. For the 90 dB peSPL click, CM amplitude was uninfluenced by click rate for conventional averaging. For MLS BAERs, CM amplitude was similar to conventional averaging for longer MPIs.(ABSTRACT TRUNCATED AT 250 WORDS).

  1. Regularity increases middle latency evoked and late induced beta brain response following proprioceptive stimulation

    DEFF Research Database (Denmark)

    Arnfred, Sidse M.; Hansen, Lars Kai; Parnas, Josef

    2008-01-01

    as an indication of increased readiness. This is achieved through detailed analysis of both evoked and induced responses in the time-frequency domain. Electroencephalography in a 64 channels montage was recorded in four-teen healthy subjects. Two paradigms were explored: A Regular alternation between hand...

  2. Automated analysis of prerecorded evoked electromyographic activity from rat muscle.

    Science.gov (United States)

    Basarab-Horwath, I; Dewhurst, D G; Dixon, R; Meehan, A S; Odusanya, S

    1989-03-01

    An automated microprocessor-based data acquisition and analysis system has been developed specifically to quantify electromyographic (EMG) activity induced by the convulsant agent catechol in the anaesthetized rat. The stimulus and EMG response are recorded on magnetic tape. On playback, the stimulus triggers a digital oscilloscope and, via interface circuitry, a BBC B microcomputer. The myoelectric activity is digitized by the oscilloscope before being transferred under computer control via a RS232 link to the microcomputer. This system overcomes the problems of dealing with signals of variable latency and allows quantification of latency, amplitude, area and frequency of occurrence of specific components within the signal. The captured data can be used to generate either signal or superimposed high resolution graphic reproductions of the original waveforms. Although this system has been designed for a specific application, it could easily be modified to allow analysis of any complex waveform.

  3. Motor-Evoked Potential Confirmation of Functional Improvement by Transplanted Bone Marrow Mesenchymal Stem Cell in the Ischemic Rat Brain

    Science.gov (United States)

    Jang, Dong-Kyu; Park, Sang-In; Han, Young-Min; Jang, Kyung-Sool; Park, Moon-Seo; Chung, Young-An; Kim, Min-Wook; Maeng, Lee-So; Huh, Pil-Woo; Yoo, Do-Sung; Jung, Seong-Whan

    2011-01-01

    This study investigated the effect of bone marrow mesenchymal stem cells (BMSCs) on the motor pathway in the transient ischemic rat brain that were transplanted through the carotid artery, measuring motor-evoked potential (MEP) in the four limbs muscle and the atlantooccipital membrane, which was elicited after monopolar and bipolar transcortical stimulation. After monopolar stimulation, the latency of MEP was significantly prolonged, and the amplitude was less reduced in the BMSC group in comparison with the control group (P < .05). MEPs induced by bipolar stimulation in the left forelimb could be measured in 40% of the BMSC group and the I wave that was not detected in the control group was also detected in 40% of the BMSC group. Our preliminary results imply that BMSCs transplanted to the ischemic rat brain mediate effects on the functional recovery of the cerebral motor cortex and the motor pathway. PMID:21772790

  4. Motor-Evoked Potential Confirmation of Functional Improvement by Transplanted Bone Marrow Mesenchymal Stem Cell in the Ischemic Rat Brain

    Directory of Open Access Journals (Sweden)

    Dong-Kyu Jang

    2011-01-01

    Full Text Available This study investigated the effect of bone marrow mesenchymal stem cells (BMSCs on the motor pathway in the transient ischemic rat brain that were transplanted through the carotid artery, measuring motor-evoked potential (MEP in the four limbs muscle and the atlantooccipital membrane, which was elicited after monopolar and bipolar transcortical stimulation. After monopolar stimulation, the latency of MEP was significantly prolonged, and the amplitude was less reduced in the BMSC group in comparison with the control group (<.05. MEPs induced by bipolar stimulation in the left forelimb could be measured in 40% of the BMSC group and the I wave that was not detected in the control group was also detected in 40% of the BMSC group. Our preliminary results imply that BMSCs transplanted to the ischemic rat brain mediate effects on the functional recovery of the cerebral motor cortex and the motor pathway.

  5. Association Between Brain Activation and Functional Connectivity.

    Science.gov (United States)

    Tomasi, Dardo; Volkow, Nora D

    2018-04-13

    The origin of the "resting-state" brain activity recorded with functional magnetic resonance imaging (fMRI) is still uncertain. Here we provide evidence for the neurovascular origins of the amplitude of the low-frequency fluctuations (ALFF) and the local functional connectivity density (lFCD) by comparing them with task-induced blood-oxygen level dependent (BOLD) responses, which are considered a proxy for neuronal activation. Using fMRI data for 2 different tasks (Relational and Social) collected by the Human Connectome Project in 426 healthy adults, we show that ALFF and lFCD have linear associations with the BOLD response. This association was significantly attenuated by a novel task signal regression (TSR) procedure, indicating that task performance enhances lFCD and ALFF in activated regions. We also show that lFCD predicts BOLD activation patterns, as was recently shown for other functional connectivity metrics, which corroborates that resting functional connectivity architecture impacts brain activation responses. Thus, our findings indicate a common source for BOLD responses, ALFF and lFCD, which is consistent with the neurovascular origin of local hemodynamic synchrony presumably reflecting coordinated fluctuations in neuronal activity. This study also supports the development of task-evoked functional connectivity density mapping.

  6. 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...

  7. 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

  8. Mechanical Compression and Nucleus Pulposus Application on Dorsal Root Ganglia Differentially Modify Evoked Neuronal Activity in the Thalamus

    Science.gov (United States)

    Nilsson, Elin; Brisby, Helena; Rask, Katarina

    2013-01-01

    Abstract A combination of mechanical compression caused by a protruding disc and leakage of nucleus pulposus (NP) from the disc core is presumed to contribute to intervertebral disc hernia-related pain. Experimental models of disc hernia including both components have resulted in changes in neuronal activity at the level of the dorsal root ganglion (DRG) and spinal cord, but changes within the brain have been less well studied. However, acute application of NP to a DRG without mechanical compression rapidly increases neuronal activity in the thalamus, a major brain relay nucleus processing information from sensory pathways including ascending nociceptive tracts. The combination of mechanical compression and NP might therefore result in further increases in central neuronal activity. Using an experimental disc herniation rat model including both mechanical compression and NP the present study aimed to investigate changes in neuronal activity in the contralateral thalamic ventral posterior lateral nucleus in vivo. Measurements were obtained while electrically stimulating the ipsilateral sciatic nerve at Aδ fiber intensities. The L4 DRG was subjected to light mechanical compression and NP exposure, and acute changes in evoked thalamic responses were recorded for up to 40 min. In order to compare effects in naïve animals with effects following a longer period of NP exposure, animals that were either disc-punctured or sham-operated 24 h previously were also included. In all animals, light mechanical compression of the DRG depressed the number of evoked neuronal responses. Prior NP exposure resulted in less potent changes following mechanical compression (80% of baseline) than that observed in naïve animals (50%). During the subsequent NP application, the number of evoked responses compared to baseline increased in pre-exposed animals (to 87%) as well as in naïve animals (72%) in which the removal of the mechanical compression resulted in a further increase (106

  9. High-frequency combination coding-based steady-state visual evoked potential for brain computer interface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng; Zhang, Xin; Xie, Jun; Li, Yeping; Han, Chengcheng; Lili, Li; Wang, Jing [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Guang-Hua [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710054 (China)

    2015-03-10

    This study presents a new steady-state visual evoked potential (SSVEP) paradigm for brain computer interface (BCI) systems. The goal of this study is to increase the number of targets using fewer stimulation high frequencies, with diminishing subject’s fatigue and reducing the risk of photosensitive epileptic seizures. The new paradigm is High-Frequency Combination Coding-Based High-Frequency Steady-State Visual Evoked Potential (HFCC-SSVEP).Firstly, we studied SSVEP high frequency(beyond 25 Hz)response of SSVEP, whose paradigm is presented on the LED. The SNR (Signal to Noise Ratio) of high frequency(beyond 40 Hz) response is very low, which is been unable to be distinguished through the traditional analysis method; Secondly we investigated the HFCC-SSVEP response (beyond 25 Hz) for 3 frequencies (25Hz, 33.33Hz, and 40Hz), HFCC-SSVEP produces n{sup n} with n high stimulation frequencies through Frequence Combination Code. Further, Animproved Hilbert-huang transform (IHHT)-based variable frequency EEG feature extraction method and a local spectrum extreme target identification algorithmare adopted to extract time-frequency feature of the proposed HFCC-SSVEP response.Linear predictions and fixed sifting (iterating) 10 time is used to overcome the shortage of end effect and stopping criterion,generalized zero-crossing (GZC) is used to compute the instantaneous frequency of the proposed SSVEP respondent signals, the improved HHT-based feature extraction method for the proposed SSVEP paradigm in this study increases recognition efficiency, so as to improve ITR and to increase the stability of the BCI system. what is more, SSVEPs evoked by high-frequency stimuli (beyond 25Hz) minimally diminish subject’s fatigue and prevent safety hazards linked to photo-induced epileptic seizures, So as to ensure the system efficiency and undamaging.This study tests three subjects in order to verify the feasibility of the proposed method.

  10. Effects of pesticides on the peripheral and central nervous system in tobacco farmers in Malaysia: studies on peripheral nerve conduction, brain-evoked potentials and computerized posturography.

    Science.gov (United States)

    Kimura, Kaoru; Yokoyama, Kazuhito; Sato, Hajime; Nordin, Rusli Bin; Naing, Lin; Kimura, Satoshi; Okabe, Shingo; Maeno, Takashi; Kobayashi, Yasuki; Kitamura, Fumihiko; Araki, Shunichi

    2005-04-01

    We examined the effects of pesticides on the central and peripheral nervous system in the setting of a tobacco farm at a developing country. Maximal motor and sensory nerve conduction velocities (MCV and SCV, respectively) in the median, sural and tibial nerves, postural sway, and brain-evoked potentials (auditory event-related and visual-evoked potentials) were measured in 80 male tobacco farmers and age- and sex-matched 40 controls in Kelantan, Malaysia. Median SCV (finger-wrist) in farmers using Delsen (mancozeb, dithiocarbamate fungicide), who showed significant decrease of serum cholinesterase activities, were significantly lower compared with the controls. Sural SCV in farmers using Fastac (alpha-cypermethrin, pyrethroid insecticide) and median MCV (elbow-wrist) in farmers using Tamex (butralin, dinitroaniline herbicide) were significantly slowed compared with their respective controls. In Delsen (mancozeb, dithiocarbamate) users, the power of postural sway of 0-1 Hz was significantly larger than that in the controls both in the anterior-posterior direction with eyes open and in the right-left direction with eyes closed. The former type of sway was also significantly increased in Tamaron (methamidophos, organophosphorus insecticide) users. In conclusion, nerve conduction velocities and postural sway seem to be sensitive indicators of the effects of pesticides on the central and peripheral nervous system.

  11. Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick M.; Blaha, Cheryl; Kunselman, Allen R.

    2012-01-01

    We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects. PMID:22707559

  12. Brain Activities and Educational Technology

    Science.gov (United States)

    Riza, Emel

    2002-01-01

    There are close relationships between brain activities and educational technology. Brain is very important and so complicated part in our bodies. From long time scientists pay attention to that part and did many experiments, but they just reached little information like a drop in the sea. However from time to time they gave us some light to…

  13. Single-trial detection of visual evoked potentials by common spatial patterns and wavelet filtering for brain-computer interface.

    Science.gov (United States)

    Tu, Yiheng; Huang, Gan; Hung, Yeung Sam; Hu, Li; Hu, Yong; Zhang, Zhiguo

    2013-01-01

    Event-related potentials (ERPs) are widely used in brain-computer interface (BCI) systems as input signals conveying a subject's intention. A fast and reliable single-trial ERP detection method can be used to develop a BCI system with both high speed and high accuracy. However, most of single-trial ERP detection methods are developed for offline EEG analysis and thus have a high computational complexity and need manual operations. Therefore, they are not applicable to practical BCI systems, which require a low-complexity and automatic ERP detection method. This work presents a joint spatial-time-frequency filter that combines common spatial patterns (CSP) and wavelet filtering (WF) for improving the signal-to-noise (SNR) of visual evoked potentials (VEP), which can lead to a single-trial ERP-based BCI.

  14. Smooth pursuit eye movement preferentially facilitates motor-evoked potential elicited by anterior-posterior current in the brain.

    Science.gov (United States)

    Hiraoka, Koichi; Ae, Minori; Ogura, Nana; Komuratani, Sayo; Sano, Chisa; Shiomi, Keigo; Morita, Yuji; Yokoyama, Haruka

    2014-03-26

    Neural interaction between the eye and hand movement centers must be a critical part of the mechanism underlying eye-hand coordination. One of the previous findings supporting this view is smooth pursuit eye movement-induced suppression of motor-evoked potential (MEP) in the hand muscles. The purpose of this study was to determine which descending volleys contributing to MEP are preferentially modulated by smooth pursuit eye movement. MEP in the first dorsal interosseous muscle was elicited by different directions of current in the brain during the steady-state phase of smooth pursuit eye movement. Smooth pursuit eye movement facilitated MEP elicited by anterior-posterior (AP) current, but this effect was not seen in MEP elicited by lateromedial or posterior-anterior current. Latency of MEP elicited by AP current was significantly longer than latencies of MEPs elicited by other directions of current, indicating that AP current in the brain predominantly elicited later I-waves. We conclude that smooth pursuit eye movement in the steady-state phase preferentially facilitates MEP predominantly elicited by later I-waves generated by AP current in the brain.

  15. Acute Exposure to Perchlorethylene alters Rat Visual Evoked Potentials in Relation to Brain Concentration

    Science.gov (United States)

    These experiments sought to establish a dose-effect relationship between the concentration of perchloroethylene (PCE) in brain tissue and concurrent changes in visual function. A physiologically-based pharmacokinetic (PBPK) model was implemented to predict concentrations of PCE ...

  16. Brownian Optogenetic-Noise-Photostimulation on the Brain Amplifies Somatosensory-Evoked Field Potentials

    Directory of Open Access Journals (Sweden)

    Nayeli Huidobro

    2017-08-01

    Full Text Available Stochastic resonance (SR is an inherent and counter-intuitive mechanism of signal-to-noise ratio (SNR facilitation in biological systems associated with the application of an intermediate level of noise. As a first step to investigate in detail this phenomenon in the somatosensory system, here we examined whether the direct application of noisy light on pyramidal neurons from the mouse-barrel cortex expressing a light-gated channel channelrhodopsin-2 (ChR2 can produce facilitation in somatosensory evoked field potentials. Using anesthetized Thy1-ChR2-YFP transgenic mice, and a new neural technology, that we called Brownian optogenetic-noise-photostimulation (BONP, we provide evidence for how BONP directly applied on the barrel cortex modulates the SNR in the amplitude of whisker-evoked field potentials (whisker-EFP. In all transgenic mice, we found that the SNR in the amplitude of whisker-EFP (at 30% of the maximal whisker-EFP exhibited an inverted U-like shape as a function of the BONP level. As a control, we also applied the same experimental paradigm, but in wild-type mice, as expected, we did not find any facilitation effects. Our results show that the application of an intermediate intensity of BONP on the barrel cortex of ChR2 transgenic mice amplifies the SNR of somatosensory whisker-EFPs. This result may be relevant to explain the improvements found in sensory detection in humans produced by the application of transcranial-random-noise-stimulation (tRNS on the scalp.

  17. Calcium imaging of infrared-stimulated activity in rodent brain

    Science.gov (United States)

    Cayce, Jonathan Matthew; Bouchard, Matthew B.; Chernov, Mykyta M.; Chen, Brenda R.; Grosberg, Lauren E.; Jansen, E. Duco; Hillman, Elizabeth M. C.; Mahadevan-Jansen, Anita

    2014-01-01

    Summary Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain. PMID:24674600

  18. Spontaneous and Evoked Activity from Murine Ventral Horn Cultures on Microelectrode Arrays

    Directory of Open Access Journals (Sweden)

    Bryan J. Black

    2017-09-01

    Full Text Available Motor neurons are the site of action for several neurological disorders and paralytic toxins, with cell bodies located in the ventral horn (VH of the spinal cord along with interneurons and support cells. Microelectrode arrays (MEAs have emerged as a high content assay platform for mechanistic studies and drug discovery. Here, we explored the spontaneous and evoked electrical activity of VH cultures derived from embryonic mouse spinal cord on multi-well plates of MEAs. Primary VH cultures from embryonic day 15–16 mice were characterized by expression of choline acetyltransferase (ChAT by immunocytochemistry. Well resolved, all-or-nothing spontaneous spikes with profiles consistent with extracellular action potentials were observed after 3 days in vitro, persisting with consistent firing rates until at least day in vitro 19. The majority of the spontaneous activity consisted of tonic firing interspersed with coordinated bursting across the network. After 5 days in vitro, spike activity was readily evoked by voltage pulses where a minimum amplitude and duration required for excitation was 300 mV and 100 μs/phase, respectively. We characterized the sensitivity of spontaneous and evoked activity to a host of pharmacological agents including AP5, CNQX, strychnine, ω-agatoxin IVA, and botulinum neurotoxin serotype A (BoNT/A. These experiments revealed sensitivity of the cultured VH to both agonist and antagonist compounds in a manner consistent with mature tissue derived from slices. In the case of BoNT/A, we also demonstrated intoxication persistence over an 18-day period, followed by partial intoxication recovery induced by N- and P/Q-type calcium channel agonist GV-58. In total, our findings suggest that VH cultures on multi-well MEA plates may represent a moderate throughput, high content assay for performing mechanistic studies and for screening potential therapeutics pertaining to paralytic toxins and neurological disorders.

  19. Intracortical circuits amplify sound-evoked activity in primary auditory cortex following systemic injection of salicylate in the rat

    Science.gov (United States)

    Chrostowski, Michael; Salvi, Richard J.; Allman, Brian L.

    2012-01-01

    A high dose of sodium salicylate temporarily induces tinnitus, mild hearing loss, and possibly hyperacusis in humans and other animals. Salicylate has well-established effects on cochlear function, primarily resulting in the moderate reduction of auditory input to the brain. Despite decreased peripheral sensitivity and output, salicylate induces a paradoxical enhancement of the sound-evoked field potential at the level of the primary auditory cortex (A1). Previous electrophysiologic studies have begun to characterize changes in thalamorecipient layers of A1; however, A1 is a complex neural circuit with recurrent intracortical connections. To describe the effects of acute systemic salicylate treatment on both thalamic and intracortical sound-driven activity across layers of A1, we applied current-source density (CSD) analysis to field potentials sampled across cortical layers in the anesthetized rat. CSD maps were normally characterized by a large, short-latency, monosynaptic, thalamically driven sink in granular layers followed by a lower amplitude, longer latency, polysynaptic, intracortically driven sink in supragranular layers. Following systemic administration of salicylate, there was a near doubling of both granular and supragranular sink amplitudes at higher sound levels. The supragranular sink amplitude input/output function changed from becoming asymptotic at approximately 50 dB to sharply nonasymptotic, often dominating the granular sink amplitude at higher sound levels. The supragranular sink also exhibited a significant decrease in peak latency, reflecting an acceleration of intracortical processing of the sound-evoked response. Additionally, multiunit (MU) activity was altered by salicylate; the normally onset/sustained MU response type was transformed into a primarily onset response type in granular and infragranular layers. The results from CSD analysis indicate that salicylate significantly enhances sound-driven response via intracortical circuits

  20. Extendable supervised dictionary learning for exploring diverse and concurrent brain activities in task-based fMRI.

    Science.gov (United States)

    Zhao, Shijie; Han, Junwei; Hu, Xintao; Jiang, Xi; Lv, Jinglei; Zhang, Tuo; Zhang, Shu; Guo, Lei; Liu, Tianming

    2017-06-09

    Recently, a growing body of studies have demonstrated the simultaneous existence of diverse brain activities, e.g., task-evoked dominant response activities, delayed response activities and intrinsic brain activities, under specific task conditions. However, current dominant task-based functional magnetic resonance imaging (tfMRI) analysis approach, i.e., the general linear model (GLM), might have difficulty in discovering those diverse and concurrent brain responses sufficiently. This subtraction-based model-driven approach focuses on the brain activities evoked directly from the task paradigm, thus likely overlooks other possible concurrent brain activities evoked during the information processing. To deal with this problem, in this paper, we propose a novel hybrid framework, called extendable supervised dictionary learning (E-SDL), to explore diverse and concurrent brain activities under task conditions. A critical difference between E-SDL framework and previous methods is that we systematically extend the basic task paradigm regressor into meaningful regressor groups to account for possible regressor variation during the information processing procedure in the brain. Applications of the proposed framework on five independent and publicly available tfMRI datasets from human connectome project (HCP) simultaneously revealed more meaningful group-wise consistent task-evoked networks and common intrinsic connectivity networks (ICNs). These results demonstrate the advantage of the proposed framework in identifying the diversity of concurrent brain activities in tfMRI datasets.

  1. Neuronal functional connection graphs among multiple areas of the rat somatosensory system during spontaneous and evoked activities.

    Science.gov (United States)

    Zippo, Antonio G; Storchi, Riccardo; Nencini, Sara; Caramenti, Gian Carlo; Valente, Maurizio; Biella, Gabriele Eliseo M

    2013-01-01

    Small-World Networks (SWNs) represent a fundamental model for the comprehension of many complex man-made and biological networks. In the central nervous system, SWN models have been shown to fit well both anatomical and functional maps at the macroscopic level. However, the functional microscopic level, where the nodes of a network are represented by single neurons, is still poorly understood. At this level, although recent evidences suggest that functional connection graphs exhibit small-world organization, it is not known whether and how these maps, potentially distributed in multiple brain regions, change across different conditions, such as spontaneous and stimulus-evoked activities. We addressed these questions by analyzing the data from simultaneous multi-array extracellular recordings in three brain regions of rats, diversely involved in somatosensory information processing: the ventropostero-lateral thalamic nuclei, the primary somatosensory cortex and the centro-median thalamic nuclei. From both spike and Local Field Potential (LFP) recordings, we estimated the functional connection graphs by using the Normalized Compression Similarity for spikes and the Phase Synchrony for LFPs. Then, by using graph-theoretical statistics, we characterized the functional topology both during spontaneous activity and sensory stimulation. Our main results show that: (i) spikes and LFPs show SWN organization during spontaneous activity; (ii) after stimulation onset, while substantial functional graph reconfigurations occur both in spike and LFPs, small-worldness is nonetheless preserved; (iii) the stimulus triggers a significant increase of inter-area LFP connections without modifying the topology of intra-area functional connections. Finally, investigating computationally the functional substrate that supports the observed phenomena, we found that (iv) the fundamental concept of cell assemblies, transient groups of activating neurons, can be described by small

  2. Blocking proteinase-activated receptor 2 alleviated neuropathic pain evoked by spinal cord injury.

    Science.gov (United States)

    Wei, H; Wei, Y; Tian, F; Niu, T; Yi, G

    2016-01-01

    Spinal cord injury (SCI) is an extremely serious type of physical trauma observed in clinics. Especially, neuropathic pain resulting from SCI has a lasting and significant impact on most aspects of daily life. Thus, a better understanding of the molecular pathways responsible for the cause of neuropathic pain observed in SCI is important to develop effectively therapeutic agents and treatment strategies. Proteinase-activated receptors (PARs) are a family member of G-protein-coupled receptors and are activated by a proteolytic mechanism. One of its subtypes PAR2 has been reported to be engaged in mechanical and thermal hyperalgesia. Thus, in this study we specifically examined the underlying mechanisms responsible for SCI evoked-neuropathic pain in a rat model. Overall, we demonstrated that SCI increases PAR2 and its downstream pathways TRPV1 and TRPA1 expression in the superficial dorsal horn of the spinal cord. Also, we showed that blocking spinal PAR2 by intrathecal injection of FSLLRY-NH2 significantly inhibits neuropathic pain responses induced by mechanical and thermal stimulation whereas FSLLRY-NH2 decreases the protein expression of TRPV1 and TRPA1 as well as the levels of substance P and calcitonin gene-related peptide. Results of this study have important implications, i.e. targeting one or more of these signaling molecules involved in activation of PAR2 and TRPV1/TRPA1 evoked by SCI may present new opportunities for treatment and management of neuropathic pain often observed in patients with SCI.

  3. Intraoperative Functional Ultrasound Imaging of Human Brain Activity.

    Science.gov (United States)

    Imbault, Marion; Chauvet, Dorian; Gennisson, Jean-Luc; Capelle, Laurent; Tanter, Mickael

    2017-08-04

    The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz), fUS is performed during surgery to measure transient changes in cerebral blood volume with a high spatiotemporal resolution (250 µm, 1 ms). fUS identifies, maps and differentiates regions of brain activation during task-evoked cortical responses within the depth of a sulcus in both awake and anaesthetized patients.

  4. Evaluation of brain stem auditory evoked potentials in stable patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Gupta Prem

    2008-01-01

    Full Text Available Though there are few studies addressing brainstem auditory evoked potentials (BAEP in patients with chronic obstructive pulmonary disease (COPD, subclinical BAEP abnormalities in stable COPD patients have not been studied. The present study aimed to evaluate the BAEP abnormalities in this study group. Materials and Methods : In the present study, 80 male subjects were included: COPD group comprised 40 smokers with stable COPD with no clinical neuropathy; 40 age-matched healthy volunteers served as the control group. Latencies of BAEP waves I, II, III, IV, and V, together with interpeak latencies (IPLs of I-III, I-V, and III-V, and amplitudes of waves I-Ia and V-Va were studied in both the groups to compare the BAEP abnormalities in COPD group; the latter were correlated with patient characteristics and Mini-Mental Status Examination Questionnaire (MMSEQ scores to seek any significant correlation. Results: Twenty-six (65% of the 40 COPD patients had BAEP abnormalities. We observed significantly prolonged latencies of waves I, III, V over left ear and waves III, IV, V over right ear; increased IPLs of I-V, III-V over left ear and of I-III, I-V, III-V over right side. Amplitudes of waves I-Ia and V-Va were decreased bilaterally. Over left ear, the latencies of wave I and III were significantly correlated with FEV 1 ; and amplitude of wave I-Ia, with smoking pack years. A weak positive correlation between amplitude of wave I-Ia and duration of illness; and a weak negative correlation between amplitude of wave V-Va and MMSEQ scores were seen over right side. Conclusions : We observed significant subclinical BAEP abnormalities on electrophysiological evaluation in studied stable COPD male patients having mild-to-moderate airflow obstruction.

  5. A Steady-State Visual Evoked Potential Brain-Computer Interface System Evaluation as an In-Vehicle Warning Device

    Science.gov (United States)

    Riyahi, Pouria

    This thesis is part of current research at Center for Intelligence Systems Research (CISR) at The George Washington University for developing new in-vehicle warning systems via Brain-Computer Interfaces (BCIs). The purpose of conducting this research is to contribute to the current gap between BCI and in-vehicle safety studies. It is based on the premise that accurate and timely monitoring of human (driver) brain's signal to external stimuli could significantly aide in detection of driver's intentions and development of effective warning systems. The thesis starts with introducing the concept of BCI and its development history while it provides a literature review on the nature of brain signals. The current advancement and increasing demand for commercial and non-medical BCI products are described. In addition, the recent research attempts in transportation safety to study drivers' behavior or responses through brain signals are reviewed. The safety studies, which are focused on employing a reliable and practical BCI system as an in-vehicle assistive device, are also introduced. A major focus of this thesis research has been on the evaluation and development of the signal processing algorithms which can effectively filter and process brain signals when the human subject is subjected to Visual LED (Light Emitting Diodes) stimuli at different frequencies. The stimulated brain generates a voltage potential, referred to as Steady-State Visual Evoked Potential (SSVEP). Therefore, a newly modified analysis algorithm for detecting the brain visual signals is proposed. These algorithms are designed to reach a satisfactory accuracy rate without preliminary trainings, hence focusing on eliminating the need for lengthy training of human subjects. Another important concern is the ability of the algorithms to find correlation of brain signals with external visual stimuli in real-time. The developed analysis models are based on algorithms which are capable of generating results

  6. A new method for registration of kinesthetic evoked potentials for studies of proprioceptive sensitivity in normal subjects and patients with organic lesions in the brain.

    Science.gov (United States)

    Gordeev, S A; Voronin, S G

    2015-01-01

    The proprioceptive sensitivity of healthy volunteers and convalescents after acute cerebrovascular episodes was studied by a new neurophysiological method for registration of kinesthetic evoked potentials emerging in response to passive 50(o) bending of the hand in the wrist joint with the angular acceleration of 350 rad/sec(2). Kinesthetic evoked potentials were recorded above the somatosensory cortex projection areas in the hemispheres contra- and ipsilateral to the stimulated limb. The patients exhibited significantly longer latencies and lesser amplitudes of the early components of response in the involved hemisphere in comparison with normal subjects. The method for registration of the kinesthetic evoked potentials allows a more detailed study of the mechanisms of kinesthetic sensitivity in health and in organic involvement of the brain.

  7. Mapping social behavior-induced brain activation at cellular resolution in the mouse

    Science.gov (United States)

    Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C.; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J.; Rockland, Kathleen; Seung, H. Sebastian; Osten, Pavel

    2014-01-01

    Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate early gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP-positive neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

  8. Concurrent OCT imaging of stimulus evoked retinal neural activation and hemodynamic responses

    Science.gov (United States)

    Son, Taeyoon; Wang, Benquan; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2017-02-01

    It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation. These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases, which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye diseases.

  9. Clinical and instrumental (magnetic resonance imaging [MRI] and multimodal evoked potentials) follow-up of brain lesions in three young patients with neurofibromatosis 1.

    Science.gov (United States)

    Margari, Lucia; Presicci, Anna; Ventura, Patrizia; Maria Bacca, Simona; Iliceto, Gianni; Medicamento, Nicola; Buttiglione, Maura; Perniola, Tommaso

    2006-12-01

    Diagnosis of neurofibromatosis 1 is based on clinical criteria. In a large number of children with neurofibromatosis 1, magnetic resonance imaging (MRI) reveals high-signal T(2)-weighted intensities in different brain regions, defined as unidentified bright objects. These lesions are asymptomatic; most of them regress spontaneously with age, but the presence of contrast enhancement or mass effect in them usually strongly suggests an increased risk of proliferative changes. To date, few studies have focused on evoked potentials in patients with neurofibromatosis 1, and the reported abnormalities did not have significant clinical correlations. We describe the clinical and instrumental (MRI and evoked potentials) follow-up of three patients with neurofibromatosis 1. MRI and evoked potentials showed subclinical involvement of the central nervous system. Some MRI T(2)-weighted hyperintensities showed enhancement and mass effect of uncertain significance. During follow-up, the MRI lesions spontaneously decreased in size or enhancement, allowing us to exclude the hypothesis of proliferative lesions; in the same way, some asymptomatic evoked potential abnormalities disappeared. These findings suggest that both MRI and evoked potentials could be useful in the detection and monitoring of cerebral complications of neurofibromatosis 1.

  10. [A wireless smart home system based on brain-computer interface of steady state visual evoked potential].

    Science.gov (United States)

    Zhao, Li; Xing, Xiao; Guo, Xuhong; Liu, Zehua; He, Yang

    2014-10-01

    Brain-computer interface (BCI) system is a system that achieves communication and control among humans and computers and other electronic equipment with the electroencephalogram (EEG) signals. This paper describes the working theory of the wireless smart home system based on the BCI technology. We started to get the steady-state visual evoked potential (SSVEP) using the single chip microcomputer and the visual stimulation which composed by LED lamp to stimulate human eyes. Then, through building the power spectral transformation on the LabVIEW platform, we processed timely those EEG signals under different frequency stimulation so as to transfer them to different instructions. Those instructions could be received by the wireless transceiver equipment to control the household appliances and to achieve the intelligent control towards the specified devices. The experimental results showed that the correct rate for the 10 subjects reached 100%, and the control time of average single device was 4 seconds, thus this design could totally achieve the original purpose of smart home system.

  11. Sequence detection analysis based on canonical correlation for steady-state visual evoked potential brain computer interfaces.

    Science.gov (United States)

    Cao, Lei; Ju, Zhengyu; Li, Jie; Jian, Rongjun; Jiang, Changjun

    2015-09-30

    Steady-state visual evoked potential (SSVEP) has been widely applied to develop brain computer interface (BCI) systems. The essence of SSVEP recognition is to recognize the frequency component of target stimulus focused by a subject significantly present in EEG spectrum. In this paper, a novel statistical approach based on sequence detection (SD) is proposed for improving the performance of SSVEP recognition. This method uses canonical correlation analysis (CCA) coefficients to observe SSVEP signal sequence. And then, a threshold strategy is utilized for SSVEP recognition. The result showed the classification performance with the longer duration of time window achieved the higher accuracy for most subjects. And the average time costing per trial was lower than the predefined recognition time. It was implicated that our approach could improve the speed of BCI system in contrast to other methods. Comparison with existing method(s): In comparison with other resultful algorithms, experimental accuracy of SD approach was better than those using a widely used CCA-based method and two newly proposed algorithms, least absolute shrinkage and selection operator (LASSO) recognition model as well as multivariate synchronization index (MSI) method. Furthermore, the information transfer rate (ITR) obtained by SD approach was higher than those using other three methods for most participants. These conclusions demonstrated that our proposed method was promising for a high-speed online BCI. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Objective assessment of visual attention in mild traumatic brain injury (mTBI) using visual-evoked potentials (VEP).

    Science.gov (United States)

    Yadav, Naveen K; Ciuffreda, Kenneth J

    2015-01-01

    To quantify visual attention objectively using the visual-evoked potential (VEP) in those having mild traumatic brain injury (mTBI) with and without a self-reported attentional deficit. Subjects were comprised of 16 adults with mTBI: 11 with an attentional deficit and five without. Three test conditions were used to assess the visual attentional state to quantify objectively the VEP alpha band attenuation ratio (AR) related to attention: (1) pattern VEP; (2) eyes-closed; and (3) eyes-closed number counting. The AR was calculated for both the individual and combined alpha frequencies (8-13 Hz). The objective results were compared to two subjective tests of visual and general attention (i.e. the VSAT and ASRS, respectively). The AR for both the individual and combined alpha frequencies was found to be abnormal in those with mTBI having an attentional deficit. In contrast, the AR was normal in those with mTBI but without an attentional deficit. The AR correlated with the ASRS, but not with the VSAT, test scores. The objective and subjective tests were able to differentiate between those having mTBI with and without an attentional deficit. The proposed VEP protocol can be used in the clinic to detect and assess objectively and reliably a visual attentional deficit in the mTBI population.

  13. Effect of oculomotor vision rehabilitation on the visual-evoked potential and visual attention in mild traumatic brain injury.

    Science.gov (United States)

    Yadav, Naveen K; Thiagarajan, Preethi; Ciuffreda, Kenneth J

    2014-01-01

    The purpose of the experiment was to investigate the effect of oculomotor vision rehabilitation (OVR) on the visual-evoked potential (VEP) and visual attention in the mTBI population. Subjects (n = 7) were adults with a history of mild traumatic brain injury (mTBI). Each received 9 hours of OVR over a 6-week period. The effects of OVR on VEP amplitude and latency, the attention-related alpha band (8-13 Hz) power (µV(2)) and the clinical Visual Search and Attention Test (VSAT) were assessed before and after the OVR. After the OVR, the VEP amplitude increased and its variability decreased. There was no change in VEP latency, which was normal. Alpha band power increased, as did the VSAT score, following the OVR. The significant changes in most test parameters suggest that OVR affects the visual system at early visuo-cortical levels, as well as other pathways which are involved in visual attention.

  14. Mapping brain activity with flexible graphene micro-transistors

    Science.gov (United States)

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

    2017-06-01

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

  15. 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; Venkataraju, Kannan Umadevi; Zhou, Yu; Wang, Victoria X.; Tang, Cheuk Y.; Olsen, Olav; Dulac, Catherine; Osten, Pavel; Tessier-Lavigne, Marc

    2016-01-01

    Summary 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. Lastly, 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

  16. Effect of a non lethal whole-body gamma irradiation on the spontaneous and evoked electroencephalographic activities of the adult rabbit

    International Nuclear Information System (INIS)

    Court, L.

    1969-01-01

    The whole of the experimental methods described (animal preparation, achievement of a precise physiological technique, dosimetry, biological information processing) allowed us to follow the changes for 15 days in the spontaneous and evoked electroencephalogram activities of rabbits submitted to a non-lethal 400 rads whole-body gamma-irradiation. Behavioural troubles, changes in the arousal state and the spontaneous electrical activity of the neo-cortex and hippocampus were noticed constantly together with an enhanced cortical excitability, and the appearance of elements of the paroxystic series sometimes in contrast with a general decrease in amplitude. After a visual stimulus the general morphology of evoked activities at the level of the primary visual areas and hippocampus was unchanged, but enhanced latencies and delays, less systematic modifications in amplitudes seemed to show out a direct effect of radiations on the nervous system and sensorial activities; these troubles seemed to occur independently from the basic electrical activity. As a whole, the changes observed were usually transitory and varied with each individual. Finally an assumption is made to explain the mechanism of arousal troubles and the general evolution of spontaneous electrical activity in the brain. (author) [fr

  17. Dissociated stimulus and response conflict effect in the Stroop task: evidence from evoked brain potentials and brain oscillations.

    Science.gov (United States)

    Zhao, Jingting; Liang, Wei-Kuang; Juan, Chi-Hung; Wang, Lin; Wang, Suiping; Zhu, Zude

    2015-01-01

    The Stroop task is a classic paradigm that can be used to examine cognitive control as it contains conditions with and without interference. Cumulative evidence suggests that both stimulus and response conflict contribute to the Stroop interference effect. However, it remains unclear whether there are dissociable event-related potential (ERP) or frequency band-specific electroencephalographic (EEG) power changes associated with stimulus conflict and response conflict. To investigate potential markers for each form of conflict, we applied a Stroop 2-1 mapping task in 20 healthy young adults. Results showed that a negative deflection in the 350-500ms time window (N450) and a positive deflection in the 600-900ms time window (late positive component, LPC) were associated with response conflict and stimulus conflict, respectively. Time-frequency analyses found that both stimulus and response conflict induced theta band power changes and that response conflict additionally induced a beta band power change. These results indicate that stimulus and response conflict in the Stroop task are associated with different ERP effects and brain oscillatory features. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Four weeks' inhalation exposure of Long Evans rats to 4-tert-butyltoluene: Effect on evoked potentials, behaviour and brain neurochemistry

    DEFF Research Database (Denmark)

    Lam, Henrik Rye; Ladefoged, Ole; Østergaard, Grete

    2000-01-01

    and somatosensory evoked potentials were not affected by TBT In Auditory Brain Stem Response there was no shift in hearing threshold, but the amplitude of the first wave was increased in both exposed groups at high stimulus levels. Three to four months after the end of exposure, behavioural studies in Morris water...... maze and eight-arm maze failed to demonstrate any TBT induced effects. Exposure was followed by a 5 months exposure-free period prior to gross regional and subcellular (synaptosomal) neurochemical investigations of the brain. TBT reduced the NA concentration in whole brain minus cerebellum......, respectively. We hypothesise that a reduced yield of synaptosomal protein reflects a more general effect of organic solvent exposure on the software of the brain. The synaptosomal concentration per mg synaptosomal protein and the total amount of 5-hydroxytryptamine were not affected whereas the total amount...

  19. 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.

  20. Activity-dependent developmental plasticity of the auditory brain stem in children who use cochlear implants.

    Science.gov (United States)

    Gordon, Karen A; Papsin, Blake C; Harrison, Robert V

    2003-12-01

    1) To determine if a period of early auditory deprivation influences neural activity patterns as revealed by human auditory brain stem potentials evoked by electrical stimulation from a cochlear implant. 2) To examine the potential for plasticity in the human auditory brain stem. Specifically, we asked if electrically evoked auditory potentials from the auditory nerve and brain stem in children show evidence of development as a result of implant use. 3) To assess whether a sensitive or critical period exists in auditory brain stem development. Specifically, is there an age of implantation after which there are no longer developmental changes in auditory brain stem activity as revealed by electrically evoked potentials? The electrically evoked compound potential of the auditory nerve (ECAP) and the electrically evoked auditory brain stem response (EABR) were recorded repeatedly during the first year of implant use in each of 50 children. The children all had pre- or peri-lingual onset of severe to profound sensorineural hearing loss and received their implants at ages ranging from 12 mo to 17 yr. All children received Nucleus cochlear implant devices. All children were in therapy and in school programs that emphasized listening and required the children to wear their implants consistently. Initial stimulation from the cochlear implant evoked clear responses from the auditory nerve and auditory brain stem in most children. There was no correlation between minimum latency, maximum amplitude, or slope of amplitude growth of initial responses with age at implantation for ECAP eN1, EABR eIII and eV components (p > 0.05). During the first year of implant use, minimum latency of these waves significantly decreased (p brain stem and EABR eIII-eV for upper brain stem, decreased during the period of 6 to 12 mo of cochlear implant use (p children underwent implantation (p plasticity that we have shown in the human auditory brain stem does not appear from EABR data to be

  1. Virtual exertions: evoking the sense of exerting forces in virtual reality using gestures and muscle activity.

    Science.gov (United States)

    Chen, Karen B; Ponto, Kevin; Tredinnick, Ross D; Radwin, Robert G

    2015-06-01

    This study was a proof of concept for virtual exertions, a novel method that involves the use of body tracking and electromyography for grasping and moving projections of objects in virtual reality (VR). The user views objects in his or her hands during rehearsed co-contractions of the same agonist-antagonist muscles normally used for the desired activities to suggest exerting forces. Unlike physical objects, virtual objects are images and lack mass. There is currently no practical physically demanding way to interact with virtual objects to simulate strenuous activities. Eleven participants grasped and lifted similar physical and virtual objects of various weights in an immersive 3-D Cave Automatic Virtual Environment. Muscle activity, localized muscle fatigue, ratings of perceived exertions, and NASA Task Load Index were measured. Additionally, the relationship between levels of immersion (2-D vs. 3-D) was studied. Although the overall magnitude of biceps activity and workload were greater in VR, muscle activity trends and fatigue patterns for varying weights within VR and physical conditions were the same. Perceived exertions for varying weights were not significantly different between VR and physical conditions. Perceived exertion levels and muscle activity patterns corresponded to the assigned virtual loads, which supported the hypothesis that the method evoked the perception of physical exertions and showed that the method was promising. Ultimately this approach may offer opportunities for research and training individuals to perform strenuous activities under potentially safer conditions that mimic situations while seeing their own body and hands relative to the scene. © 2014, Human Factors and Ergonomics Society.

  2. Musical Brains. A study of evoked musical sensations without external auditory stimuli. Preliminary report of three cases

    International Nuclear Information System (INIS)

    Goycoolea, Marcos V; Mena, Ismael; Neubauer, Sonia G; Levy, Raquel G.; Fernandez Grez, Margarita; Berger, Claudia G

    2006-01-01

    Background: There are individuals, usually musicians, who are seemingly able to evoke musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors nor if there is a biological substrate to these sensations. Study design: Two single photon emission computerized tomography (SPECT) evaluations with [99mTc]-HMPAO were conducted in each of three female musicians. One was done under basal conditions (without evoking) and the other one while evoking these sensations. Results: In the NeuroSPECT studies of the musicians who were tested while evoking a musical composition, there was a significant increase in perfusion above the normal mean in the right and left hemispheres in Brodmann's areas 9 and 8 (frontal executive area) and in areas 40 on the left side (auditory center). However, under basal conditions there was no hyper perfusion of areas 9, 8, 39 and 40. In one case hyper perfusion was found under basal conditions in area 45, however it was less than when she was evoking. Conclusions: These findings are suggestive of a biological substrate to the process of evoking musical sensations (au)

  3. Cholinergic pairing with visual activation results in long-term enhancement of visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Jun Il Kang

    Full Text Available Acetylcholine (ACh contributes to learning processes by modulating cortical plasticity in terms of intensity of neuronal activity and selectivity properties of cortical neurons. However, it is not known if ACh induces long term effects within the primary visual cortex (V1 that could sustain visual learning mechanisms. In the present study we analyzed visual evoked potentials (VEPs in V1 of rats during a 4-8 h period after coupling visual stimulation to an intracortical injection of ACh analog carbachol or stimulation of basal forebrain. To clarify the action of ACh on VEP activity in V1, we individually pre-injected muscarinic (scopolamine, nicotinic (mecamylamine, alpha7 (methyllycaconitine, and NMDA (CPP receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual stimulation significantly increased VEP amplitude (56% during a 6 h period. Pre-treatment with scopolamine, mecamylamine and CPP completely abolished this long-term enhancement, while alpha7 inhibition induced an instant increase of VEP amplitude. This suggests a role of ACh in facilitating visual stimuli responsiveness through mechanisms comparable to LTP which involve nicotinic and muscarinic receptors with an interaction of NMDA transmission in the visual cortex.

  4. 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.

  5. 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

  6. [Evoked activity of the cat hypothalamus and amygdala under food motivation and in emotional stress].

    Science.gov (United States)

    Pavlova, I V; Vanetsian, G L

    2004-12-01

    Amplitude-latency characteristics of auditory evoked potentials (EPs) recorded in bilateral points of the lateral hypothalamus and amygdala were studied under food motivation, in emotional stress (presentation of dogs) and tentative reactions. In the state of hunger, as compared with safety, the latencies of P1, N2 components of EP in hypothalamus, and P1, N2, N3 in amygdala were decreased and their amplitudes were changed. Changes in the left side of both structures were more pronounced. During presentation of dogs, decreases of latencies of all EP components including N1 occurred in hypothalamus and amygdala, changes in hypothalamic potentials were more pronounced on the right side, whereas in the amygdala--on the left side. During tentative responses to emotional-neutral stimuli, the latency of EP increased. It was concluded that sensory reactivity of hypothalamus and amygdala increased in motivational-emotional states. It was supposed that the side of dominance of structure may be related both to the factors of active or passive behavior during fear and the genesis of emotion (motivational or informational).

  7. Evoked bioelectrical activity of efferent fibers of the sciatic nerve of white rats in experimental menopause

    Directory of Open Access Journals (Sweden)

    Rodinsky A.G.

    2016-03-01

    Full Text Available The aim of our work was analysis of the bioelectrical activity of efferent fibers of the sciatic nerve in experimental menopause condition. Experiments were performed on 25 female white rats, divided into experimental and control groups. Menopause was modeled by total ovariohysterectomy. In 120 days after modeling we had recorded evoked action potentials of fibers of isolated ventral root L5 induced by stimulation of sciatic nerve with rectangular pulses. Threshold, chronaxia, latency, amplitude and duration of the action potential (AP were analysed. Refractory phenomenon was investigated by applying paired stimuli at intervals of 2 to 20 ms. In the context of long-term hypoestrogenemy threshold of AP appearance was 55,32±7,69%, chronaxy – 115,09±2,67%, latent period – 112,62±1,74% as compared with the control animals (p<0.01. In conditions of paired stimuli applying the amplitude of response to the testing stimulus in animals with ovariohysterectomy at intervals 3 and 4 ms was 61,25±36,45% and 53,48±18,64% (p<0.05 respectively.

  8. Auditory evoked responses in musicians during passive vowel listening are modulated by functional connectivity between bilateral auditory-related brain regions.

    Science.gov (United States)

    Kühnis, Jürg; Elmer, Stefan; Jäncke, Lutz

    2014-12-01

    Currently, there is striking evidence showing that professional musical training can substantially alter the response properties of auditory-related cortical fields. Such plastic changes have previously been shown not only to abet the processing of musical sounds, but likewise spectral and temporal aspects of speech. Therefore, here we used the EEG technique and measured a sample of musicians and nonmusicians while the participants were passively exposed to artificial vowels in the context of an oddball paradigm. Thereby, we evaluated whether increased intracerebral functional connectivity between bilateral auditory-related brain regions may promote sensory specialization in musicians, as reflected by altered cortical N1 and P2 responses. This assumption builds on the reasoning that sensory specialization is dependent, at least in part, on the amount of synchronization between the two auditory-related cortices. Results clearly revealed that auditory-evoked N1 responses were shaped by musical expertise. In addition, in line with our reasoning musicians showed an overall increased intracerebral functional connectivity (as indexed by lagged phase synchronization) in theta, alpha, and beta bands. Finally, within-group correlative analyses indicated a relationship between intracerebral beta band connectivity and cortical N1 responses, however only within the musicians' group. Taken together, we provide first electrophysiological evidence for a relationship between musical expertise, auditory-evoked brain responses, and intracerebral functional connectivity among auditory-related brain regions.

  9. Real-time classification of auditory sentences using evoked cortical activity in humans.

    Science.gov (United States)

    Moses, David Aaron; Leonard, Matthew; Chang, Edward F

    2018-01-30

    Recent research has characterized the anatomical and functional basis of speech perception in the human auditory cortex. These advances have made it possible to decode speech information from activity in brain regions like the superior temporal gyrus, but no published work has demonstrated this ability in real-time, which is necessary for neuroprosthetic brain-computer interfaces. Here, we introduce a real-time Neural Speech Recognition (rtNSR) software package, which was used to classify spoken input from high-resolution electrocorticography signals in real-time. We tested the system with two human subjects implanted with electrode arrays over the lateral brain surface. Subjects listened to multiple repetitions of ten sentences, and rtNSR classified what was heard in real-time from neural activity patterns using direct sentence-level and HMM-based phoneme-level classification schemes. We observed single-trial sentence classification accuracies of 90% or higher for each subject with less than 7 minutes of training data, demonstrating the ability of rtNSR to use cortical recordings to perform accurate real-time speech decoding in a limited vocabulary setting. Further development and testing of the package with different speech paradigms could influence the design of future speech neuroprosthetic applications. © 2018 IOP Publishing Ltd.

  10. Sensory and semantic activations evoked by action attributes of manipulable objects: Evidence from ERPs.

    Science.gov (United States)

    Lee, Chia-Lin; Huang, Hsu-Wen; Federmeier, Kara D; Buxbaum, Laurel J

    2018-02-15

    "Two route" theories of object-related action processing posit different temporal activation profiles of grasp-to-move actions (rapidly evoked based on object structure) versus skilled use actions (more slowly activated based on semantic knowledge). We capitalized on the exquisite temporal resolution and multidimensionality of Event-Related Potentials (ERPs) to directly test this hypothesis. Participants viewed manipulable objects (e.g., calculator) preceded by objects sharing either "grasp", "use", or no action attributes (e.g., bar of soap, keyboard, earring, respectively), as well as by action-unrelated but taxonomically-related objects (e.g., abacus); participants judged whether the two objects were related. The results showed more positive responses to "grasp-to-move" primed objects than "skilled use" primed objects or unprimed objects starting in the P1 (0-150 ms) time window and continuing onto the subsequent N1 and P2 components (150-300 ms), suggesting that only "grasp-to-move", but not "skilled use", actions may facilitate visual attention to object attributes. Furthermore, reliably reduced N400s (300-500 ms), an index of semantic processing, were observed to taxonomically primed and "skilled use" primed objects relative to unprimed objects, suggesting that "skilled use" action attributes are a component of distributed, multimodal semantic representations of objects. Together, our findings provide evidence supporting two-route theories by demonstrating that "grasp-to-move" and "skilled use" actions impact different aspects of object processing and highlight the relationship of "skilled use" information to other aspects of semantic memory. Copyright © 2017. Published by Elsevier Inc.

  11. Neural FFA3 activation inversely regulates anion secretion evoked by nicotinic ACh receptor activation in rat proximal colon.

    Science.gov (United States)

    Kaji, Izumi; Akiba, Yasutada; Konno, Kohtarou; Watanabe, Masahiko; Kimura, Shunsuke; Iwanaga, Toshihiko; Kuri, Ayaka; Iwamoto, Ken-Ichi; Kuwahara, Atsukazu; Kaunitz, Jonathan D

    2016-06-15

    Luminal short-chain fatty acids (SCFAs) influence gut physiological function via SCFA receptors and transporters. The contribution of an SCFA receptor, free fatty acid receptor (FFA)3, to the enteric nervous system is unknown. FFA3 is expressed in enteric cholinergic neurons. Activation of neural FFA3 suppresses Cl(-) secretion induced by nicotinic ACh receptor activation via a Gi/o pathway. Neural FFA3 may have an anti-secretory function by modulating cholinergic neural reflexes in the enteric nervous system. The proximal colonic mucosa is constantly exposed to high concentrations of microbially-produced short-chain fatty acids (SCFAs). Although luminal SCFAs evoke electrogenic anion secretion and smooth muscle contractility via neural and non-neural cholinergic pathways in the colon, the involvement of the SCFA receptor free fatty acid receptor (FFA)3, one of the free fatty acid receptor family members, has not been clarified. We investigated the contribution of FFA3 to cholinergic-mediated secretory responses in rat proximal colon. FFA3 was immunolocalized to enteroendocrine cells and to the enteric neural plexuses. Most FFA3-immunoreactive nerve fibres and nerve endings were cholinergic, colocalized with protein gene product (PGP)9.5, the vesicular ACh transporter, and the high-affinity choline transporter CHT1. In Ussing chambered mucosa-submucosa preparations (including the submucosal plexus) of rat proximal colon, carbachol (CCh)-induced Cl(-) secretion was decreased by TTX, hexamethonium, and the serosal FFA3 agonists acetate or propionate, although not by an inactive analogue 3-chloropropionate. Serosal application of a selective FFA3 agonist (N-[2-methylphenyl]-[4-furan-3-yl]-2-methyl-5-oxo-1,4,5,6,7,8-hexahydro-quinoline-3-carboxamide; MQC) dose-dependently suppressed the response to CCh but not to forskolin, with an IC50 of 13 μm. Pretreatment with MQC inhibited nicotine-evoked but not bethanechol-evoked secretion. The inhibitory effect of MQC was

  12. Contribution of bacterial pathogens to evoking serological disease markers and aggravating disease activity in rheumatoid arthritis

    Science.gov (United States)

    Waritani, Takaki; Fukai, Richio; Shionoya, Hiroshi; Itoh, Hiroshi

    2018-01-01

    that multiple environmental pathogens, which overwhelm the host antibody defense function, contribute independently or concomitantly to evoking disease makers and aggravating disease activity, and affect disease outcomes. Trial registration: UMIN CTR UMIN000012200 PMID:29408886

  13. Contribution of bacterial pathogens to evoking serological disease markers and aggravating disease activity in rheumatoid arthritis.

    Science.gov (United States)

    Terato, Kuniaki; Waritani, Takaki; Fukai, Richio; Shionoya, Hiroshi; Itoh, Hiroshi; Katayama, Kou

    2018-01-01

    that multiple environmental pathogens, which overwhelm the host antibody defense function, contribute independently or concomitantly to evoking disease makers and aggravating disease activity, and affect disease outcomes. UMIN CTR UMIN000012200.

  14. Changes in Mice Brain Spontaneous Electrical Activity during Cortical Spreading Depression due to Mobile Phone Radiation.

    Science.gov (United States)

    Sallam, Samera M; Mohamed, Ehab I; Dawood, Abdel-Fattah B

    2008-06-01

    The objective of the present study was to investigate changes in spontaneous EEG activity during cortical spreading depression (CSD) in mice brain. The cortical region of anaesthetized mice were exposed to the electromagnetic fields (EMFs) emitted from a mobile phone (MP, 935.2-960.2 MHz, 41.8 mW/cm(2)). The effect of EMFs on EEG was investigated before and after exposure to different stimuli (MP, 2% KCl, and MP & 2% KCl). The records of brain spontaneous EEG activity, slow potential changes (SPC), and spindle shaped firings were obtained through an interfaced computer. The results showed increases in the amplitude of evoked spindles by about 87%, 17%, and 226% for MP, 2% KCl, and MP & 2% KCl; respectively, as compared to values for the control group. These results showed that the evoked spindle is a more sensitive indicator of the effect of exposure to EMFs from MP.

  15. The Role of Visual Noise in Influencing Mental Load and Fatigue in a Steady-State Motion Visual Evoked Potential-Based Brain-Computer Interface.

    Science.gov (United States)

    Xie, Jun; Xu, Guanghua; Luo, Ailing; Li, Min; Zhang, Sicong; Han, Chengcheng; Yan, Wenqiang

    2017-08-14

    As a spatial selective attention-based brain-computer interface (BCI) paradigm, steady-state visual evoked potential (SSVEP) BCI has the advantages of high information transfer rate, high tolerance to artifacts, and robust performance across users. However, its benefits come at the cost of mental load and fatigue occurring in the concentration on the visual stimuli. Noise, as a ubiquitous random perturbation with the power of randomness, may be exploited by the human visual system to enhance higher-level brain functions. In this study, a novel steady-state motion visual evoked potential (SSMVEP, i.e., one kind of SSVEP)-based BCI paradigm with spatiotemporal visual noise was used to investigate the influence of noise on the compensation of mental load and fatigue deterioration during prolonged attention tasks. Changes in α , θ , θ + α powers, θ / α ratio, and electroencephalography (EEG) properties of amplitude, signal-to-noise ratio (SNR), and online accuracy, were used to evaluate mental load and fatigue. We showed that presenting a moderate visual noise to participants could reliably alleviate the mental load and fatigue during online operation of visual BCI that places demands on the attentional processes. This demonstrated that noise could provide a superior solution to the implementation of visual attention controlling-based BCI applications.

  16. Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats.

    Science.gov (United States)

    Walsh, Kathryn R; Kuwabara, Jill T; Shim, Joon W; Wainford, Richard D

    2016-01-15

    Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension. Copyright © 2016 the American Physiological Society.

  17. Support vector regression correlates single-sweep evoked brain potentials to gastrointestinal symptoms in diabetes mellitus patients

    DEFF Research Database (Denmark)

    Graversen, C; Frokjaer, J B; Brock, Christina

    2012-01-01

    Diabetes mellitus (DM) is a multi-factorial and complex disease causing autonomic neuropathy and gastrointestinal symptoms in some patients. The neural mechanisms behind these symptoms are poorly understood, but it is believed that both peripheral and central mechanisms are involved. To gain furt...... approach to study central mechanisms in diabetes mellitus, and may provide a future application for a clinical tool to optimize treatment in individual patients.......Diabetes mellitus (DM) is a multi-factorial and complex disease causing autonomic neuropathy and gastrointestinal symptoms in some patients. The neural mechanisms behind these symptoms are poorly understood, but it is believed that both peripheral and central mechanisms are involved. To gain...... further knowledge of the central mechanisms, the aim of this study was to identify biomarkers for the altered brain activity in type-1 DM patients compared to healthy volunteers (HV), and to correlate the obtained biomarkers to clinical patient scores. The study included 14 DM patients and 15 HV...

  18. Examining sensory ability, feature matching and assessment-based adaptation for a brain-computer interface using the steady-state visually evoked potential.

    Science.gov (United States)

    Brumberg, Jonathan S; Nguyen, Anh; Pitt, Kevin M; Lorenz, Sean D

    2018-01-31

    We investigated how overt visual attention and oculomotor control influence successful use of a visual feedback brain-computer interface (BCI) for accessing augmentative and alternative communication (AAC) devices in a heterogeneous population of individuals with profound neuromotor impairments. BCIs are often tested within a single patient population limiting generalization of results. This study focuses on examining individual sensory abilities with an eye toward possible interface adaptations to improve device performance. Five individuals with a range of neuromotor disorders participated in four-choice BCI control task involving the steady state visually evoked potential. The BCI graphical interface was designed to simulate a commercial AAC device to examine whether an integrated device could be used successfully by individuals with neuromotor impairment. All participants were able to interact with the BCI and highest performance was found for participants able to employ an overt visual attention strategy. For participants with visual deficits to due to impaired oculomotor control, effective performance increased after accounting for mismatches between the graphical layout and participant visual capabilities. As BCIs are translated from research environments to clinical applications, the assessment of BCI-related skills will help facilitate proper device selection and provide individuals who use BCI the greatest likelihood of immediate and long term communicative success. Overall, our results indicate that adaptations can be an effective strategy to reduce barriers and increase access to BCI technology. These efforts should be directed by comprehensive assessments for matching individuals to the most appropriate device to support their complex communication needs. Implications for Rehabilitation Brain computer interfaces using the steady state visually evoked potential can be integrated with an augmentative and alternative communication device to provide access

  19. Alterations of brain activity in fibromyalgia patients.

    Science.gov (United States)

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

    2017-04-01

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

  20. Topographic distribution of direct and hippocampus- mediated entorhinal cortex activity evoked by olfactory tract stimulation.

    Science.gov (United States)

    Gnatkovsky, Vadym; Uva, Laura; de Curtis, Marco

    2004-10-01

    Olfactory information is central for memory-related functions, such as recognition and spatial orientation. To understand the role of olfaction in learning and memory, the distribution and propagation of olfactory tract-driven activity in the parahippocampal region needs to be characterized. We recently demonstrated that repetitive stimulation of the olfactory tract in the isolated guinea pig brain preparation induces an early direct activation of the rostrolateral entorhinal region followed by a delayed response in the medial entorhinal cortex (EC), preceded by the interposed activation of the hippocampus. In the present study we performed a detailed topographic analysis of both the early and the delayed entorhinal responses induced by patterned stimulation of the lateral olfactory tract in the isolated guinea pig brain. Bi-dimensional maps of EC activity recorded at 128 recording sites with 4 x 4 matrix electrodes (410 microm interlead separation) sequentially placed in eight different positions, showed (i) an early (onset at 16.09 +/- 1.2 ms) low amplitude potential mediated by the monosynaptic LOT input, followed by (ii) an associative potential in the rostral EC which originates from the piriform cortex (onset at 33.2 +/- 2.3 ms), and (iii) a delayed potential dependent on the previous activation of the hippocampus. The sharp component of the delayed response had an onset latency between 52 and 63 ms and was followed by a slow wave. Laminar profile analysis demonstrated that in the caudomedial EC the delayed response was associated with two distinct current sinks located in deep and in superficial layers, whereas in the rostrolateral EC a small-amplitude sink could be detected in the superficial layers exclusively. The present report demonstrates that the output generated by the hippocampal activation is unevenly distributed across different EC subregions and indicates that exclusively the medial and caudal divisions receive a deep-layer input from the

  1. Functional Laterality of Task-Evoked Activation in Sensorimotor Cortex of Preterm Infants: An Optimized 3 T fMRI Study Employing a Customized Neonatal Head Coil.

    Science.gov (United States)

    Scheef, Lukas; Nordmeyer-Massner, Jurek A; Smith-Collins, Adam Pr; Müller, Nicole; Stegmann-Woessner, Gaby; Jankowski, Jacob; Gieseke, Jürgen; Born, Mark; Seitz, Hermann; Bartmann, Peter; Schild, Hans H; Pruessmann, Klaas P; Heep, Axel; Boecker, Henning

    2017-01-01

    Functional magnetic resonance imaging (fMRI) in neonates has been introduced as a non-invasive method for studying sensorimotor processing in the developing brain. However, previous neonatal studies have delivered conflicting results regarding localization, lateralization, and directionality of blood oxygenation level dependent (BOLD) responses in sensorimotor cortex (SMC). Amongst the confounding factors in interpreting neonatal fMRI studies include the use of standard adult MR-coils providing insufficient signal to noise, and liberal statistical thresholds, compromising clinical interpretation at the single subject level. Here, we employed a custom-designed neonatal MR-coil adapted and optimized to the head size of a newborn in order to improve robustness, reliability and validity of neonatal sensorimotor fMRI. Thirteen preterm infants with a median gestational age of 26 weeks were scanned at term-corrected age using a prototype 8-channel neonatal head coil at 3T (Achieva, Philips, Best, NL). Sensorimotor stimulation was elicited by passive extension/flexion of the elbow at 1 Hz in a block design. Analysis of temporal signal to noise ratio (tSNR) was performed on the whole brain and the SMC, and was compared to data acquired with an 'adult' 8 channel head coil published previously. Task-evoked activation was determined by single-subject SPM8 analyses, thresholded at p lateralization of SMC activation, as found in children and adults, is already present in the newborn period.

  2. Stress-restress evokes sustained iNOS activity and altered GABA levels and NMDA receptors in rat hippocampus

    DEFF Research Database (Denmark)

    Harvey, Brian H; Oosthuizen, Frasia; Brand, Linda

    2004-01-01

    . The NOS isoform involved, and the role of stress-mediated corticosterone release in NOS activation, was verified with the administration of selective iNOS and nNOS inhibitors, aminoguanidine (50 mg/kg/day i.p.) and 7-nitroindazole (12.5 mg/kg/day i.p.), and the steroid synthesis inhibitor, ketoconazole...... (24 mg/kg/day i.p.), administered for 21 days prior to and during the stress procedure. RESULTS: Stress evoked a sustained increase in NOS activity, but reduced NMDA receptor density and total GABA levels. Aminoguanidine or ketoconazole, but not 7-nitroindazole or saline, blocked stress-induced NOS...

  3. Music-Evoked Emotions-Current Studies.

    Science.gov (United States)

    Schaefer, Hans-Eckhardt

    2017-01-01

    The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

  4. 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.

  5. Acute 5-HT7 receptor activation increases NMDA-evoked currents and differentially alters NMDA receptor subunit phosphorylation and trafficking in hippocampal neurons.

    Science.gov (United States)

    Vasefi, Maryam S; Yang, Kai; Li, Jerry; Kruk, Jeff S; Heikkila, John J; Jackson, Michael F; MacDonald, John F; Beazely, Michael A

    2013-05-14

    N-methyl-D-aspartate (NMDA) receptors are regulated by several G protein-coupled receptors (GPCRs) as well as receptor tyrosine kinases. Serotonin (5-HT) type 7 receptors are expressed throughout the brain including the thalamus and hippocampus. Long-term (2-24 h) activation of 5-HT7 receptors promotes the expression of neuroprotective growth factor receptors, including the platelet-derived growth factor (PDGF) β receptors which can protect neurons against NMDA-induced neurotoxicity. In contrast to long-term activation of 5-HT7 receptors, acute (5 min) treatment of isolated hippocampal neurons with the 5-HT7 receptor agonist 5-carboxamidotryptamine (5-CT) enhances NMDA-evoked peak currents and this increase in peak currents is blocked by the 5-HT7 receptor antagonist, SB 269970. In hippocampal slices, acute 5-HT7 receptor activation increases NR1 NMDA receptor subunit phosphorylation and differentially alters the phosphorylation state of the NR2B and NR2A subunits. NMDA receptor subunit cell surface expression is also differentially altered by 5-HT7 receptor agonists: NR2B cell surface expression is decreased whereas NR1 and NR2A surface expression are not significantly altered. In contrast to the negative regulatory effects of long-term activation of 5-HT7 receptors on NMDA receptor signaling, acute activation of 5-HT7 receptors promotes NMDA receptor activity. These findings highlight the potential for temporally differential regulation of NMDA receptors by the 5-HT7 receptor.

  6. 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.

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

    Science.gov (United States)

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

    2015-10-01

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

  8. Does Aerobic Exercise Influence Intrinsic Brain Activity?

    DEFF Research Database (Denmark)

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

    2017-01-01

    Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78 years) were randomized into either an aerobic...... exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling...... group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings...

  9. Prognostic Value of Cortically Induced Motor Evoked Activity by TMS in Chronic Stroke: Caveats from a Revealing Single Clinical Case

    LENUS (Irish Health Repository)

    Amengual, Julià L

    2012-06-08

    AbstractBackgroundWe report the case of a chronic stroke patient (62 months after injury) showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS) of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand.Case presentationMultimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP), and Cortical Silent period (CSP) as well as functional magnetic resonance imaging (fMRI) of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI) Tractography of corticospinal tract (CST). Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG) activity (indexed by CSP) demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations.ConclusionsThe potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.

  10. Towards a neural basis of music-evoked emotions.

    Science.gov (United States)

    Koelsch, Stefan

    2010-03-01

    Music is capable of evoking exceptionally strong emotions and of reliably affecting the mood of individuals. Functional neuroimaging and lesion studies show that music-evoked emotions can modulate activity in virtually all limbic and paralimbic brain structures. These structures are crucially involved in the initiation, generation, detection, maintenance, regulation and termination of emotions that have survival value for the individual and the species. Therefore, at least some music-evoked emotions involve the very core of evolutionarily adaptive neuroaffective mechanisms. Because dysfunctions in these structures are related to emotional disorders, a better understanding of music-evoked emotions and their neural correlates can lead to a more systematic and effective use of music in therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2011-10-05

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

  12. Ocular vestibular-evoked myogenic potentials (oVEMPs) require extraocular muscles but not facial or cochlear nerve activity.

    Science.gov (United States)

    Chihara, Yasuhiro; Iwasaki, Shinichi; Ushio, Munetaka; Fujimoto, Chisato; Kashio, Akinori; Kondo, Kenji; Ito, Ken; Asakage, Takahiro; Yamasoba, Tatsuya; Kaga, Kimitaka; Murofushi, Toshihisa

    2009-03-01

    Cervical vestibular evoked myogenic potentials (cVEMPs) have been found to be useful for clinical testing of vestibular function. Recently, investigators showed that short-latency, initially negative surface EMG potentials can be recorded around the extraocular muscles (oVEMPs) in response to air-conducted sound (ACS), bone-conducted vibration (BCV), and head taps. Although these evoked potentials, which are located around the eyes, most likely originate primarily from the otolith-ocular pathway, the possibility of contamination by other nerve activities cannot be completely eliminated. The purpose of the present study was to clarify the origin of oVEMPs by examining these possibilities using clinical findings. Twelve healthy subjects and 15 patients were enrolled. Of the 15 patients, 3 patients had undergone exenteration of the unilateral intraorbital contents, one had undergone exenteration of the right eyeball with preservation of extraocular muscles, 5 had facial palsy, and 6 had profound hearing loss. ACS and/or BCV were used in these subjects. Exenteration of the unilateral intraorbital contents resulted in absence of myogenic potentials on the affected side. On the other hand, exenteration of the eyeball with preservation of extraocular muscles did not have a major impact on the responses. There were no significant differences in the waveforms between healthy subjects and patients with facial palsy or profound hearing loss. The results suggested that short-latency, initially negative evoked potentials recorded below the eyes are not affected by cochlear or facial nerve activities and are dependent on the presence of extraocular muscles. This study provides the evidence that oVEMPs originate from exraocular muscles activated through the vestibulo-ocular pathway.

  13. Stressor-responsive central nesfatin-1 activates corticotropin-releasing hormone, noradrenaline and serotonin neurons and evokes hypothalamic-pituitary-adrenal axis

    Science.gov (United States)

    Yoshida, Natsu; Maejima, Yuko; Sedbazar, Udval; Ando, Akihiko; Kurita, Hideharu; Damdindorj, Boldbaatar; Takano, Eisuke; Gantulga, Darambazar; Iwasaki, Yusaku; Kurashina, Tomoyuki; Onaka, Tatsushi; Dezaki, Katsuya; Nakata, Masanori; Mori, Masatomo; Yada, Toshihiko

    2010-01-01

    A recently discovered satiety molecule, nesfatin-1, is localized in neurons of the hypothalamus and brain stem and colocalized with stress-related substances, corticotropin-releasing hormone (CRH), oxytocin, proopiomelanocortin, noradrenaline (NA) and 5-hydroxytryptamine (5-HT). Intracerebroventricular (icv) administration of nesfatin-1 produces fear-related behaviors and potentiates stressor-induced increases in plasma adrenocorticotropic hormone (ACTH) and corticosterone levels in rats. These findings suggest a link between nesfatin-1 and stress. In the present study, we aimed to further clarify the neuronal network by which nesfatin-1 could induce stress responses in rats. Restraint stress induced c-Fos expressions in nesfatin-1-immunoreactive neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus, and in the nucleus of solitary tract (NTS), locus coeruleus (LC) and dorsal raphe nucleus (DR) in the brain stem, without altering plasma nesfatin-1 levels. Icv nesfatin-1 induced c-Fos expressions in the PVN, SON, NTS, LC, DR and median raphe nucleus, including PVN-CRH, NTS-NA, LC-NA and DR-5-HT neurons. Nesfatin-1 increased cytosolic Ca2+ concentration in the CRH-immunoreactive neurons isolated from PVN. Icv nesfatin-1 increased plasma ACTH and corticosterone levels. These results indicate that the central nesfatin-1 system is stimulated by stress and activates CRH, NA and 5-HT neurons and hypothalamic-pituitary-adrenal axis, evoking both central and peripheral stress responses. PMID:20966530

  14. TRPM7 is required within zebrafish sensory neurons for the activation of touch-evoked escape behaviors

    Science.gov (United States)

    Low, Sean E.; Amburgey, Kimberly; Horstick, Eric; Linsley, Jeremy; Sprague, Shawn M.; Cui, Wilson W.; Zhou, Weibin; Hirata, Hiromi; Saint-Amant, Louis; Hume, Richard I.; Kuwada, John Y.

    2011-01-01

    Mutations in the gene encoding TRPM7 (trpm7), a member of the TRP superfamily of cation channels that possesses an enzymatically active kinase at its carboxyl terminus, cause the touch-unresponsive zebrafish mutant touchdown. We identified and characterized a new allele of touchdown, as well as two previously reported alleles, and found that all three alleles harbor mutations which abolish channel activity. Through the selective restoration of TRPM7 expression in sensory neurons we found that TRPM7’s kinase activity, and selectivity for divalent cations over monovalent cations, were dispensable for touch-evoked activation of escape behaviors in zebrafish. Additional characterization revealed that sensory neurons were present and capable of responding to tactile stimuli in touchdown mutants, indicating that TRPM7 is not required for sensory neuron survival or mechanosensation. Finally, exposure to elevated concentrations of divalent cations was found to restore touch-evoked behaviors in touchdown mutants. Collectively these findings are consistent with a role for zebrafish TRPM7 within sensory neurons in the modulation of neurotransmitter release at central synapses, similar to that proposed for mammalian TRPM7 at peripheral synapses. PMID:21832193

  15. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... contralateral to stimulus side and additionally an unexpected 20 Hz activity was observed slightly lateralized in the frontal central region. The gamma phase locking may be a manifestation of early somatosensory feature integration. The analyses suggest that the high frequency activity consists of two distinct...

  16. Cortico-cortical and motor evoked potentials to single and paired-pulse stimuli: An exploratory transcranial magnetic and intracranial electric brain stimulation study.

    Science.gov (United States)

    Boulogne, Sébastien; Andre-Obadia, Nathalie; Kimiskidis, Vasilios K; Ryvlin, Philippe; Rheims, Sylvain

    2016-11-01

    Paired-pulse (PP) paradigms are commonly employed to assess in vivo cortical excitability using transcranial magnetic stimulation (TMS) to stimulate the primary motor cortex and modulate the induced motor evoked potential (MEP). Single-pulse cortical direct electrical stimulation (DES) during intracerebral EEG monitoring allows the investigation of brain connectivity by eliciting cortico-cortical evoked potentials (CCEPs). However, PP paradigm using intracerebral DES has rarely been reported and has never been previously compared with TMS. The work was intended (i) to verify that the well-established modulations of MEPs following PP TMS remain similar using DES in the motor cortex, and (ii) to evaluate if a similar pattern could be observed in distant cortico-cortical connections through modulations of CCEP. Three patients undergoing intracerebral EEG monitoring with electrodes implanted in the central region were studied. Single-pulse DES (1-3 mA, 1 ms, 0.2 Hz) and PP DES using six interstimulus intervals (5, 15, 30, 50, 100, and 200 ms) in the motor cortex with concomitant recording of CCEPs and MEPs in contralateral muscles were performed. Finally, a navigated PP TMS session targeted the intracranial stimulation site to record TMS-induced MEPs in two patients. MEP modulations elicited by PP intracerebral DES proved similar among the three patients and to those obtained by PP TMS. CCEP modulations elicited by PP intracerebral DES usually showed a pattern comparable to that of MEP, although a different pattern could be observed occasionally. PP intracerebral DES seems to involve excitatory and inhibitory mechanisms similar to PP TMS and allows the recording of intracortical inhibition and facilitation modulation on cortico-cortical connections. Hum Brain Mapp 37:3767-3778, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Cortical evoked potentials to an auditory illusion: binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2009-08-01

    To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

  18. Functional selectivity of central Gα-subunit proteins in mediating the cardiovascular and renal excretory responses evoked by central α(2) -adrenoceptor activation in vivo.

    Science.gov (United States)

    Wainford, R D; Kapusta, D R

    2012-05-01

    Activation of brain α(2) -adrenoceptors in conscious rodents decreases heart rate (HR) and mean arterial blood pressure (MAP) and increases urine output and urinary sodium excretion. In vitro, α(2) -adrenoceptor stimulation activates Gα(i(1-3)) , Gα(o) and Gα(s) -subunit protein-gated signal transduction pathways. Here we have investigated whether these same Gα-subunit protein-gated pathways mediate the cardiovascular and renal excretory responses to central α(2) -adrenoceptor activation in conscious Sprague-Dawley rats. Rats were pre-treated by intracerebroventricular injection (i.c.v.) with an oligodeoxynucleotide (ODN) targeted to a Gα(i1) , Gα(i2) , Gα(i3) , Gα(o) , Gα(s) or a scrambled (SCR) ODN sequence (25 µg, 24 h). On the day of study, the α(2) -adrenoceptor agonist guanabenz (50 µg) or saline vehicle, was injected i.c.v. into ODN-pre-treated conscious rats. MAP and HR were recorded, and urine was collected for 150 min. In vehicle- and SCR ODN-pre-treated rats, i.c.v. guanabenz decreased MAP and HR, and produced marked diuretic and natriuretic responses. Selective ODN-mediated down-regulation of brain Gα(i2) -subunit proteins abolished the central guanabenz-induced hypotension and natriuresis. In contrast, following selective Gα(s) down-regulation, the characteristic hypotensive response to i.c.v. guanabenz was converted to an immediate increase in MAP. The bradycardic and diuretic responses to i.c.v. guanabenz were not blocked by pre-treatment with any ODN. There was functional selectivity of Gα(i2) and Gα(s) subunit protein-gated signal transduction pathways in mediating the hypotensive and natriuretic, but not bradycardic or diuretic, responses evoked by central α(2) -adrenoceptor activation in vivo. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  19. Interactions between procedural learning and cocaine exposure alter spontaneous and cortically-evoked spike activity in the dorsal striatum

    Directory of Open Access Journals (Sweden)

    Janie eOndracek

    2010-12-01

    Full Text Available We have previously shown that cocaine enhances gene regulation in the sensorimotor striatum associated with procedural learning in a running-wheel paradigm. Here we assessed whether cocaine produces enduring modifications of learning-related changes in striatal neuron activity, using single-unit recordings in anesthetized rats 1 day after the wheel training. Spontaneous and cortically-evoked spike activity was compared between groups treated with cocaine or vehicle immediately prior to the running-wheel training or placement in a locked wheel (control conditions. We found that wheel training in vehicle-treated rats increased the average firing rate of spontaneously active neurons without changing the relative proportion of active to quiescent cells. In contrast, in rats trained under the influence of cocaine, the proportion of spontaneously firing to quiescent cells was significantly greater than in vehicle-treated, trained rats. However, this effect was associated with a lower average firing rate in these spontaneously active cells, suggesting that training under the influence of cocaine recruited additional low-firing cells. Measures of cortically-evoked activity revealed a second interaction between cocaine treatment and wheel training, namely, a cocaine-induced decrease in spike onset latency in control rats (locked wheel. This facilitatory effect of cocaine was abolished when rats trained in the running wheel during cocaine action. These findings highlight important interactions between cocaine and procedural learning, which act to modify population firing activity and the responsiveness of striatal neurons to excitatory inputs. Moreover, these effects were found 24 hours after the training and last drug exposure indicating that cocaine exposure during the learning phase triggers long-lasting changes in synaptic plasticity in the dorsal striatum. Such changes may contribute to the transition from recreational to habitual or compulsive drug

  20. Functional mapping of brain synapses by the enriching activity-marker SynaptoZip.

    Science.gov (United States)

    Ferro, Mattia; Lamanna, Jacopo; Ripamonti, Maddalena; Racchetti, Gabriella; Arena, Alessandro; Spadini, Sara; Montesano, Giovanni; Cortese, Riccardo; Zimarino, Vincenzo; Malgaroli, Antonio

    2017-10-31

    Ideally, elucidating the role of specific brain circuits in animal behavior would require the ability to measure activity at all involved synapses, possibly with unrestricted field of view, thus even at those boutons deeply located into the brain. Here, we introduce and validate an efficient scheme reporting synaptic vesicle cycling in vivo. This is based on SynaptoZip, a genetically encoded molecule deploying in the vesicular lumen a bait moiety designed to capture upon exocytosis a labeled alien peptide, Synbond. The resulting signal is cumulative and stores the number of cycling events occurring at individual synapses. Since this functional signal is enduring and measurable both online and ex post, SynaptoZip provides a unique method for the analysis of the history of synaptic activity in regions several millimeters below the brain surface. We show its broad applicability by reporting stimulus-evoked and spontaneous circuit activity in wide cortical fields, in anesthetized and freely moving animals.

  1. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...... a minor effect on the power spectra, i.e. the maximum jumps from one spectral peak to another. Experiments with deconvolution demonstrate that the emission generating system at least at a fixed intensity can be regarded as being linear and characterized by its impulse response which is similar...... to the emission evoked by click stimuli. It is concluded that significant information is obtained by the click rather than by the tonal stimuli. The click-evoked emissions were also recorded from both ears in a consecutive series of 100 full-term and otherwise normal babies 2-4 days after birth. The emission...

  2. Whole-brain activity mapping onto a zebrafish brain atlas

    Science.gov (United States)

    Randlett, Owen; Wee, Caroline L.; Naumann, Eva A.; Nnaemeka, Onyeka; Schoppik, David; Fitzgerald, James E.; Portugues, Ruben; Lacoste, Alix M.B.; Riegler, Clemens; Engert, Florian; Schier, Alexander F.

    2015-01-01

    In order to localize the neural circuits involved in generating behaviors, it is necessary to assign activity onto anatomical maps of the nervous system. Using brain registration across hundreds of larval zebrafish, we have built an expandable open source atlas containing molecular labels and anatomical region definitions, the Z-Brain. Using this platform and immunohistochemical detection of phosphorylated-Extracellular signal-regulated kinase (ERK/MAPK) as a readout of neural activity, we have developed a system to create and contextualize whole brain maps of stimulus- and behavior-dependent neural activity. This MAP-Mapping (Mitogen Activated Protein kinase – Mapping) assay is technically simple, fast, inexpensive, and data analysis is completely automated. Since MAP-Mapping is performed on fish that are freely swimming, it is applicable to nearly any stimulus or behavior. We demonstrate the utility of our high-throughput approach using hunting/feeding, pharmacological, visual and noxious stimuli. The resultant maps outline hundreds of areas associated with behaviors. PMID:26778924

  3. Whole-brain activity mapping onto a zebrafish brain atlas.

    Science.gov (United States)

    Randlett, Owen; Wee, Caroline L; Naumann, Eva A; Nnaemeka, Onyeka; Schoppik, David; Fitzgerald, James E; Portugues, Ruben; Lacoste, Alix M B; Riegler, Clemens; Engert, Florian; Schier, Alexander F

    2015-11-01

    In order to localize the neural circuits involved in generating behaviors, it is necessary to assign activity onto anatomical maps of the nervous system. Using brain registration across hundreds of larval zebrafish, we have built an expandable open-source atlas containing molecular labels and definitions of anatomical regions, the Z-Brain. Using this platform and immunohistochemical detection of phosphorylated extracellular signal–regulated kinase (ERK) as a readout of neural activity, we have developed a system to create and contextualize whole-brain maps of stimulus- and behavior-dependent neural activity. This mitogen-activated protein kinase (MAP)-mapping assay is technically simple, and data analysis is completely automated. Because MAP-mapping is performed on freely swimming fish, it is applicable to studies of nearly any stimulus or behavior. Here we demonstrate our high-throughput approach using pharmacological, visual and noxious stimuli, as well as hunting and feeding. The resultant maps outline hundreds of areas associated with behaviors.

  4. An Idle-State Detection Algorithm for SSVEP-Based Brain-Computer Interfaces Using a Maximum Evoked Response Spatial Filter.

    Science.gov (United States)

    Zhang, Dan; Huang, Bisheng; Wu, Wei; Li, Siliang

    2015-11-01

    Although accurate recognition of the idle state is essential for the application of brain-computer interfaces (BCIs) in real-world situations, it remains a challenging task due to the variability of the idle state. In this study, a novel algorithm was proposed for the idle state detection in a steady-state visual evoked potential (SSVEP)-based BCI. The proposed algorithm aims to solve the idle state detection problem by constructing a better model of the control states. For feature extraction, a maximum evoked response (MER) spatial filter was developed to extract neurophysiologically plausible SSVEP responses, by finding the combination of multi-channel electroencephalogram (EEG) signals that maximized the evoked responses while suppressing the unrelated background EEGs. The extracted SSVEP responses at the frequencies of both the attended and the unattended stimuli were then used to form feature vectors and a series of binary classifiers for recognition of each control state and the idle state were constructed. EEG data from nine subjects in a three-target SSVEP BCI experiment with a variety of idle state conditions were used to evaluate the proposed algorithm. Compared to the most popular canonical correlation analysis-based algorithm and the conventional power spectrum-based algorithm, the proposed algorithm outperformed them by achieving an offline control state classification accuracy of 88.0 ± 11.1% and idle state false positive rates (FPRs) ranging from 7.4 ± 5.6% to 14.2 ± 10.1%, depending on the specific idle state conditions. Moreover, the online simulation reported BCI performance close to practical use: 22.0 ± 2.9 out of the 24 control commands were correctly recognized and the FPRs achieved as low as approximately 0.5 event/min in the idle state conditions with eye open and 0.05 event/min in the idle state condition with eye closed. These results demonstrate the potential of the proposed algorithm for implementing practical SSVEP BCI systems.

  5. Brain–Immune Interaction Accompanying Odor-Evoked Autobiographic Memory

    Science.gov (United States)

    Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

    2013-01-01

    The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions. PMID:23977312

  6. Middle latency auditory-evoked potential index monitoring of cerebral function to predict functional outcome after emergency craniotomy in patients with brain damage.

    Science.gov (United States)

    Tsurukiri, Junya; Nagata, Katsuhiro; Hoshiai, Akira; Oomura, Taishi; Jimbo, Hiroyuki; Ikeda, Yukio

    2015-10-20

    At present, no satisfactory reports on the monitoring of cerebral function to predict functional outcomes after brain damage such as traumatic brain injury (TBI) and stroke. The middle latency auditory-evoked potential index (MLAEPi) monitor (aepEX plus®, Audiomex, UK) is a mobile MLAEP monitor measuring the degree of consciousness that is represented by numerical values. Hence, we hypothesized that MLAEPi predicts neurological outcome after emergency craniotomy among patients with disturbance of consciousness (DOC), which was caused by brain damage. The afore-mentioned patients who underwent emergency craniotomy within 12 h of brain damage and were subsequently monitored using MLAEPi were enrolled in this study. DOC was defined as an initial Glasgow Coma Scale score craniotomy. Neurological outcome was evaluated before discharge using a cerebral performance category (CPC) score and classified into three groups: favorable outcome group for a CPC score of 1 or 2, unfavorable outcome group for a score of 3 or 4, and brain dead (BD) group for a score of 5. Thirty-two patients were included in this study (17 with TBIs and 15 with acute stroke). Regarding outcome, 10 patients had a favorable outcome, 15 had an unfavorable outcome, and 7 were pronounced BD. MLAEPi was observed to be significantly higher on day 5 than that observed immediately after craniotomy in cases of favorable or unfavorable outcome (63 ± 3.5 vs. 36 ± 2.5 in favorable outcome; 63 ± 3.5 vs. 34 ± 1.8 in unfavorable outcome). MLAEPi was significantly lower in BD patients than in those with a favorable or unfavorable outcome on day 3 (24 ± 4.2 in BD vs. 52 ± 5.2 and 45 ± 2.7 in favorable and unfavorable outcome, respectively) and after day 4. MLAEPi was significantly higher in patients with a favorable outcome than in those with a favorable or unfavorable outcome after day 6 (68 ± 2.3 in favorable outcome vs. 48 ± 2.3 in unfavorable outcome). We believe that MLAEPi satisfactorily denotes

  7. Average is optimal: an inverted-U relationship between trial-to-trial brain activity and behavioral performance.

    Directory of Open Access Journals (Sweden)

    Biyu J He

    Full Text Available It is well known that even under identical task conditions, there is a tremendous amount of trial-to-trial variability in both brain activity and behavioral output. Thus far the vast majority of event-related potential (ERP studies investigating the relationship between trial-to-trial fluctuations in brain activity and behavioral performance have only tested a monotonic relationship between them. However, it was recently found that across-trial variability can correlate with behavioral performance independent of trial-averaged activity. This finding predicts a U- or inverted-U- shaped relationship between trial-to-trial brain activity and behavioral output, depending on whether larger brain variability is associated with better or worse behavior, respectively. Using a visual stimulus detection task, we provide evidence from human electrocorticography (ECoG for an inverted-U brain-behavior relationship: When the raw fluctuation in broadband ECoG activity is closer to the across-trial mean, hit rate is higher and reaction times faster. Importantly, we show that this relationship is present not only in the post-stimulus task-evoked brain activity, but also in the pre-stimulus spontaneous brain activity, suggesting anticipatory brain dynamics. Our findings are consistent with the presence of stochastic noise in the brain. They further support attractor network theories, which postulate that the brain settles into a more confined state space under task performance, and proximity to the targeted trajectory is associated with better performance.

  8. Biological Activity of Propolis-Honey Balm in the Treatment of Experimentally-Evoked Burn Wounds

    Directory of Open Access Journals (Sweden)

    Żaneta Jastrzębska-Stojko

    2013-11-01

    Full Text Available Medicines of biogenic origin with micro-organic, regenerative and analgesic properties are becoming more and more significant in the treatment of burn wounds. These properties are found in apitherapeutics such as propolis and honey—products collected and processed by a honey bee. Their effect on the course of the healing processes is multidirectional. The aim of the study was a histopathological and biochemical analysis of the processes of scar formation in experimentally evoked burn wounds in white pigs treated with the 1% and 3% Sepropol balms containing standardized extracts of propolis and honey. The results were compared with the therapeutic effects obtained with dermazin cream (1% silver sulfadiazine. The level of collagen was determined in the wounds treated with 1% and 3% Sepropol and compared with the collagen level in healthy skin and wounds treated with dermazin. Granulation and regenerated epithelium formation times were compared, with the 3% Sepropol being by far the most effective. The 3% Sepropol also increased the collagen level to 116% with the control sub-groups scoring between 80% and 98%. The results show the healing process of burn wounds in pigs treated with the Sepropol balm starts earlier and has a faster course than the standard dermazin therapy.

  9. Characterizing neural activities evoked by manual acupuncture through spiking irregularity measures

    International Nuclear Information System (INIS)

    Xue Ming; Wang Jiang; Deng Bin; Wei Xi-Le; Yu Hai-Tao; Chen Ying-Yuan

    2013-01-01

    The neural system characterizes information in external stimulations by different spiking patterns. In order to examine how neural spiking patterns are related to acupuncture manipulations, experiments are designed in such a way that different types of manual acupuncture (MA) manipulations are taken at the ‘Zusanli’ point of experimental rats, and the induced electrical signals in the spinal dorsal root ganglion are detected and recorded. The interspike interval (ISI) statistical histogram is fitted by the gamma distribution, which has two parameters: one is the time-dependent firing rate and the other is a shape parameter characterizing the spiking irregularities. The shape parameter is the measure of spiking irregularities and can be used to identify the type of MA manipulations. The coefficient of variation is mostly used to measure the spike time irregularity, but it overestimates the irregularity in the case of pronounced firing rate changes. However, experiments show that each acupuncture manipulation will lead to changes in the firing rate. So we combine four relatively rate-independent measures to study the irregularity of spike trains evoked by different types of MA manipulations. Results suggest that the MA manipulations possess unique spiking statistics and characteristics and can be distinguished according to the spiking irregularity measures. These studies have offered new insights into the coding processes and information transfer of acupuncture. (interdisciplinary physics and related areas of science and technology)

  10. Mobile-phone pulse triggers evoked potentials.

    Science.gov (United States)

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

    2010-01-18

    If mobile-phone electromagnetic fields (EMFs) are hazardous, as suggested in the literature, processes or mechanisms must exist that allow the body to detect the fields. We hypothesized that the low-frequency pulses produced by mobile phones (217 Hz) were detected by sensory transduction, as evidenced by the ability of the pulses to trigger evoked potentials (EPs). Electroencephalograms (EEGs) were recorded from six standard locations in 20 volunteers and analyzed to detect brain potentials triggered by a pulse of the type produced by mobile phones. Evoked potentials having the expected latency were found in 90% of the volunteers, as assessed using a nonlinear method of EEG analysis. Evoked potentials were not detected when the EEG was analyzed using time averaging. The possibility of systematic error was excluded by sham-exposure analyses. The results implied that mobile-phones trigger EP at the rate of 217 Hz during ordinary phone use. Chronic production of the changes in brain activity might be pertinent to the reports of health hazards among mobile-phone users. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  11. The relationship between nociceptive brain activity, spinal reflex withdrawal and behaviour in newborn infants

    Science.gov (United States)

    Hartley, Caroline; Goksan, Sezgi; Poorun, Ravi; Brotherhood, Kelly; Mellado, Gabriela Schmidt; Moultrie, Fiona; Rogers, Richard; Adams, Eleri; Slater, Rebeccah

    2015-01-01

    Measuring infant pain is complicated by their inability to describe the experience. While nociceptive brain activity, reflex withdrawal and facial grimacing have been characterised, the relationship between these activity patterns has not been examined. As cortical and spinally mediated activity is developmentally regulated, it cannot be assumed that they are predictive of one another in the immature nervous system. Here, using a new experimental paradigm, we characterise the nociceptive-specific brain activity, spinal reflex withdrawal and behavioural activity following graded intensity noxious stimulation and clinical heel lancing in 30 term infants. We show that nociceptive-specific brain activity and nociceptive reflex withdrawal are graded with stimulus intensity (p < 0.001), significantly correlated (r = 0.53, p = 0.001) and elicited at an intensity that does not evoke changes in clinical pain scores (p = 0.55). The strong correlation between reflex withdrawal and nociceptive brain activity suggests that movement of the limb away from a noxious stimulus is a sensitive indication of nociceptive brain activity in term infants. This could underpin the development of new clinical pain assessment measures. PMID:26228435

  12. Asymmetric Frontal Brain Activity and Parental Rejection

    NARCIS (Netherlands)

    Huffmeijer, R.; Alink, L.R.A.; Tops, M.; Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.

    2013-01-01

    Asymmetric frontal brain activity has been widely implicated in reactions to emotional stimuli and is thought to reflect individual differences in approach-withdrawal motivation. Here, we investigate whether asymmetric frontal activity, as a measure of approach-withdrawal motivation, also predicts

  13. Interactions between dyspnea and the brain processing of nociceptive stimuli:experimental air hunger attenuates laser-evoked brain potentials in humans.

    Directory of Open Access Journals (Sweden)

    Laurence eDANGERS

    2015-12-01

    Full Text Available Dyspnea and pain share several characteristics and certain neural networks and interact with each other. Dyspnea-pain counter-irritation consists of attenuation of preexisting pain by intercurrent dyspnea and has been shown to have neurophysiological correlates in the form of inhibition of the nociceptive spinal reflex RIII and laser-evoked potentials (LEPs. Experimentally induced exertional dyspnea inhibits RIII and LEPs, while air hunger dyspnea does not inhibit RIII despite its documented analgesic effects. We hypothesized that air hunger may act centrally and inhibit LEPs. LEPs were obtained in 12 healthy volunteers (age: 21-29 during spontaneous breathing (FB, ventilator-controlled breathing (VC tailored to FB, after inducing air hunger by increasing the inspired fraction of carbon dioxide -FiCO2- (VCCO2, and during ventilator-controlled breathing recovery (VCR. VCCO2 induced intense dyspnea (visual analogue scale = 63% ± 6% of full scale, p<0.001 vs. VC, predominantly of the air hunger type. VC alone reduced the amplitude of the N2-P2 component of LEPs (∆ = 24.0% ± 21.1%, p<0.05, effect-size = 0.74 predominantly through a reduction in P2, and the amplitude of this inhibition was further reduced by inducting air hunger (∆ = 22.6% ± 17.9%, p<0.05, effect-size = 0.53, predominantly through a reduction in N2. Somatosensory-evoked potentials (SEPs were not affected by VC or VCCO2, suggesting that the observed effects are specific to pain transmission. We conclude that air hunger interferes with the cortical mechanisms responsible for the cortical response to painful laser skin stimulation, which provides a neurophysiological substrate to the central nature of its otherwise documented analgesic effects.

  14. Idiosyncratic Brain Activation Patterns Are Associated with Poor Social Comprehension in Autism

    Science.gov (United States)

    Tyszka, J. Michael; Adolphs, Ralph; Kennedy, Daniel P.

    2015-01-01

    Autism spectrum disorder (ASD) features profound social deficits but neuroimaging studies have failed to find any consistent neural signature. Here we connect these two facts by showing that idiosyncratic patterns of brain activation are associated with social comprehension deficits. Human participants with ASD (N = 17) and controls (N = 20) freely watched a television situation comedy (sitcom) depicting seminaturalistic social interactions (“The Office”, NBC Universal) in the scanner. Intersubject correlations in the pattern of evoked brain activation were reduced in the ASD group—but this effect was driven entirely by five ASD subjects whose idiosyncratic responses were also internally unreliable. The idiosyncrasy of these five ASD subjects was not explained by detailed neuropsychological profile, eye movements, or data quality; however, they were specifically impaired in understanding the social motivations of characters in the sitcom. Brain activation patterns in the remaining ASD subjects were indistinguishable from those of control subjects using multiple multivariate approaches. Our findings link neurofunctional abnormalities evoked by seminaturalistic stimuli with a specific impairment in social comprehension, and highlight the need to conceive of ASD as a heterogeneous classification. PMID:25855192

  15. Sensory-evoked perturbations of locomotor activity by sparse sensory input: a computational study

    OpenAIRE

    Bui, Tuan V.; Brownstone, Robert M.

    2015-01-01

    Sensory inputs from muscle, cutaneous, and joint afferents project to the spinal cord, where they are able to affect ongoing locomotor activity. Activation of sensory input can initiate or prolong bouts of locomotor activity depending on the identity of the sensory afferent activated and the timing of the activation within the locomotor cycle. However, the mechanisms by which afferent activity modifies locomotor rhythm and the distribution of sensory afferents to the spinal locomotor networks...

  16. Functional Laterality of Task-Evoked Activation in Sensorimotor Cortex of Preterm Infants: An Optimized 3 T fMRI Study Employing a Customized Neonatal Head Coil.

    Directory of Open Access Journals (Sweden)

    Lukas Scheef

    Full Text Available Functional magnetic resonance imaging (fMRI in neonates has been introduced as a non-invasive method for studying sensorimotor processing in the developing brain. However, previous neonatal studies have delivered conflicting results regarding localization, lateralization, and directionality of blood oxygenation level dependent (BOLD responses in sensorimotor cortex (SMC. Amongst the confounding factors in interpreting neonatal fMRI studies include the use of standard adult MR-coils providing insufficient signal to noise, and liberal statistical thresholds, compromising clinical interpretation at the single subject level.Here, we employed a custom-designed neonatal MR-coil adapted and optimized to the head size of a newborn in order to improve robustness, reliability and validity of neonatal sensorimotor fMRI. Thirteen preterm infants with a median gestational age of 26 weeks were scanned at term-corrected age using a prototype 8-channel neonatal head coil at 3T (Achieva, Philips, Best, NL. Sensorimotor stimulation was elicited by passive extension/flexion of the elbow at 1 Hz in a block design. Analysis of temporal signal to noise ratio (tSNR was performed on the whole brain and the SMC, and was compared to data acquired with an 'adult' 8 channel head coil published previously. Task-evoked activation was determined by single-subject SPM8 analyses, thresholded at p < 0.05, whole-brain FWE-corrected.Using a custom-designed neonatal MR-coil, we found significant positive BOLD responses in contralateral SMC after unilateral passive sensorimotor stimulation in all neonates (analyses restricted to artifact-free data sets = 8/13. Improved imaging characteristics of the neonatal MR-coil were evidenced by additional phantom and in vivo tSNR measurements: phantom studies revealed a 240% global increase in tSNR; in vivo studies revealed a 73% global and a 55% local (SMC increase in tSNR, as compared to the 'adult' MR-coil.Our findings strengthen the

  17. Memory, Cognition and the Endogenous Evoked Potentials of the Brain: the Estimation of the Disturbance of Cognitive Functions and Capacity of Working Memory Without the Psychological Testing.

    Science.gov (United States)

    Gnezditskiy, V V; Korepina, O S; Chatskaya, A V; Klochkova, O I

    2017-01-01

    Cognition, cognitive and memory impairments is widely discussed in the literature, especially in the psycho physiological and the neurologic. In essence, this literature is dedicated to the psycho physiological tests, different scales. However, instrument neurophysiologic methods not so widely are used for these purposes. This review is dedicated to the instrument methods of neurophysiology, in particular to the endogenous evoked potentials method Р 300 (by characteristic latency 300 ms), in the estimation of cognitive functions and memory, to their special features dependent on age and to special features to their changes with the pathology. Method cognitive EP - Р 300 is the response of the brain, recorded under the conditions of the identification of the significant distinguishing stimulus, it facilitates the inspection of cognitive functions and memory in the healthy persons and patients with different manifestation of cognitive impairments. In the review it is shown on the basis of literature and our own data, that working (operative) memory and the capacity of the working memory it can be evaluated with the aid of the indices Р 300 within the normal subject and with the pathology. Testing with the estimation of working memory according to latent period of the peak Р 300 can be carried out and when conducting psychological testing is not possible for any reasons. Together with these cognitive EP are used for evidence pharmacotherapy of many neurotropic drugs.

  18. Hearing impairment in children with congenital cytomegalovirus (CMV) infection based on distortion product otoacoustic emissions (DPOAE) and brain evoked response audiometry stimulus click (BERA Click) examinations

    Science.gov (United States)

    Airlangga, T. J.; Mangunatmadja, I.; Prihartono, J.; Zizlavsky, S.

    2017-08-01

    Congenital cytomegalovirus (congenital CMV) infection is a leading factor of nongenetic sensorineural hearing loss in children. Hearing loss caused by CMV infection does not have a pathognomonic configuration hence further research is needed. The development of knowledge on hearing loss caused by congenital CMV infection is progressing in many countries. Due to a lack of research in the context of Indonesia, this study assesses hearing impairment in children with congenital CMV infection in Indonesia, more specifically in the Cipto Mangunkusumo Hospital. Our objective was to profile hearing impairment in children 0-5 years of age with congenital CMV infection using Distortion Product Otoacoustic Emissions (DPOAE) and Brain Evoked Response Audiometry Stimulus Click (BERA Click) examinations. This cross-sectional study was conducted in the Cipto Mangunkusum Hospital from November, 2015 to May 2016 with 27 children 0-5 years of age with congenital CMV infection. Of individual ears studied, 58.0% exhibited sensorineural hearing loss. There was a significant relationship between developmental delay and incidence of sensorineural hearing loss. Subjects with a developmental delay were 6.57 times more likely (CI 95%; 1.88-22.87) to experience sensorineural hearing loss. Congenital CMV infection has an important role in causing sensorineural hearing loss in children.

  19. Intraoperative cortico-cortical evoked potentials for the evaluation of language function during brain tumor resection: initial experience with 13 cases.

    Science.gov (United States)

    Saito, Taiichi; Tamura, Manabu; Muragaki, Yoshihiro; Maruyama, Takashi; Kubota, Yuichi; Fukuchi, Satoko; Nitta, Masayuki; Chernov, Mikhail; Okamoto, Saori; Sugiyama, Kazuhiko; Kurisu, Kaoru; Sakai, Kuniyoshi L; Okada, Yoshikazu; Iseki, Hiroshi

    2014-10-01

    The objective in the present study was to evaluate the usefulness of cortico-cortical evoked potentials (CCEP) monitoring for the intraoperative assessment of speech function during resection of brain tumors. Intraoperative monitoring of CCEP was applied in 13 patients (mean age 34 ± 14 years) during the removal of neoplasms located within or close to language-related structures in the dominant cerebral hemisphere. For this purpose strip electrodes were positioned above the frontal language area (FLA) and temporal language area (TLA), which were identified with direct cortical stimulation and/or preliminary mapping with the use of implanted chronic subdural grid electrodes. The CCEP response was defined as the highest observed negative peak in either direction of stimulation. In 12 cases the tumor was resected during awake craniotomy. An intraoperative CCEP response was not obtained in one case because of technical problems. In the other patients it was identified from the FLA during stimulation of the TLA (7 cases) and from the TLA during stimulation of the FLA (5 cases), with a mean peak latency of 83 ± 15 msec. During tumor resection the CCEP response was unchanged in 5 cases, decreased in 4, and disappeared in 3. Postoperatively, all 7 patients with a decreased or absent CCEP response after lesion removal experienced deterioration in speech function. In contrast, in 5 cases with an unchanged intraoperative CCEP response, speaking abilities after surgery were preserved at the preoperative level, except in one patient who experienced not dysphasia, but dysarthria due to pyramidal tract injury. This difference was statistically significant (p brain tumors affecting language-related cerebral structures. In the intraoperative evaluation of speech function, it can be a helpful adjunct or can be used in its direct assessment with cortical and subcortical mapping during awake craniotomy. It can also be used to predict the prognosis of language disorders after surgery

  20. Modulation of hippocampal activity with fornix Deep Brain Stimulation.

    Science.gov (United States)

    Stypulkowski, Paul H; Stanslaski, Scott R; Giftakis, Jonathon E

    Deep Brain Stimulation (DBS) within the Papez circuit is under investigation as a treatment for epilepsy and Alzheimer's disease. We previously reported the effects of stimulation at nodes within this network (anterior thalamic nucleus and hippocampus) on hippocampal activity in a large animal model, using a chronic implantable, clinical-grade system that permits concurrent stimulation and recording. In this study we extended earlier work to compare the effects of fornix DBS on evoked potentials (EPs) and local field potential (LFP) activity within the hippocampus, and to assess closed-loop stimulation. Unilateral fornix and hippocampal DBS leads were implanted in three ovine subjects using image-guided, frameless stereotaxy. Chronic, awake recordings of EPs and LFPs in response to fornix and hippocampal stimulation were collected with the implanted device and analyzed off-line. Stimulation of the fornix produced robust, short latency hippocampal EPs. High frequency fornix stimulation generated parameter-dependent effects. At low amplitudes, short lasting inhibition of LFP activity occurred. Above a specific amplitude threshold, DBS elicited pronounced bursts of theta activity, followed by a marked state shift in hippocampal activity. These effects persisted for minutes post-DBS and were reflected as changes in LFP spectral content and phase-amplitude coupling. Real-time modulation of hippocampal activity via the implanted device was demonstrated using LFPs as the control signal for closed-loop stimulation. The current results expand earlier findings and demonstrate target-specific effects produced by DBS within this neural circuit. These changes in network activity may provide insights into stimulation targets and parameter selection for clinical investigations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Brain stimulation used as biofeedback in neuronal activation of the temporal lobe area in autistic children

    Directory of Open Access Journals (Sweden)

    Vernon Furtado da Silva

    2016-08-01

    Full Text Available ABSTRACT This study focused upon the functional capacity of mirror neurons in autistic children. 30 individuals, 10 carriers of the autistic syndrome (GCA, 10 with intellectual impairments (GDI, and 10 non-autistics (GCN had registered eletroencephalogram from the brain area theoretically related to mirror neurons. Data collection procedure occurred prior to brain stimulation and after the stimulation session. During the second session, participants had to alternately process figures evoking neutral, happy, and/or sorrowful feelings. Results proved that, for all groups, the stimulation process in fact produced additional activation in the neural area under study. The level of activation was related to the format of emotional stimuli and the likelihood of boosting such stimuli. Since the increase of activation occurred in a model similar to the one observed for the control group, we may suggest that the difficulty people with autism have at expressing emotions is not due to nonexistence of mirror neurons.

  2. Music-Evoked Emotions—Current Studies

    Science.gov (United States)

    Schaefer, Hans-Eckhardt

    2017-01-01

    The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields. PMID:29225563

  3. Music-Evoked Emotions—Current Studies

    Directory of Open Access Journals (Sweden)

    Hans-Eckhardt Schaefer

    2017-11-01

    Full Text Available The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI and positron emission tomography (PET, which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG, event-related brain potentials (ERP, magnetoencephalography (MEG, skin conductance response (SCR, finger temperature, and goose bump development (piloerection can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

  4. Interactions Between Dyspnea and the Brain Processing of Nociceptive Stimuli: Experimental Air Hunger Attenuates Laser-Evoked Brain Potentials in Humans.

    Science.gov (United States)

    Dangers, Laurence; Laviolette, Louis; Similowski, Thomas; Morélot-Panzini, Capucine

    2015-01-01

    Dyspnea and pain share several characteristics and certain neural networks and interact with each other. Dyspnea-pain counter-irritation consists of attenuation of preexisting pain by intercurrent dyspnea and has been shown to have neurophysiological correlates in the form of inhibition of the nociceptive spinal reflex RIII and laser-evoked potentials (LEPs). Experimentally induced exertional dyspnea inhibits RIII and LEPs, while "air hunger" dyspnea does not inhibit RIII despite its documented analgesic effects. We hypothesized that air hunger may act centrally and inhibit LEPs. LEPs were obtained in 12 healthy volunteers (age: 21-29) during spontaneous breathing (FB), ventilator-controlled breathing (VC) tailored to FB, after inducing air hunger by increasing the inspired fraction of carbon dioxide -FiCO2- (VCCO2), and during ventilator-controlled breathing recovery (VCR). VCCO2 induced intense dyspnea (visual analog scale = 63% ± 6% of full scale, p air hunger type. VC alone reduced the amplitude of the N2-P2 component of LEPs (Δ = 24.0% ± 21.1%, p air hunger (Δ = 22.6% ± 17.9%, p air hunger interferes with the cortical mechanisms responsible for the cortical response to painful laser skin stimulation, which provides a neurophysiological substrate to the central nature of its otherwise documented analgesic effects.

  5. Size matters to function: Brain volume correlates with intrinsic brain activity across healthy individuals.

    Science.gov (United States)

    Qing, Zhao; Gong, Gaolang

    2016-10-01

    A fundamental issue in neuroscience is to understand the structural substrates of neural activities. Intrinsic brain activity has been increasingly recognized as an important functional activity mode and is tightly linked with various cognitive functions. Structurally, cognitive functions have also shown a relation with brain volume/size. Therefore, an association between intrinsic brain activities and brain volume/size can be hypothesized, and brain volume/size may impact intrinsic brain activity in human brains. The present study aimed to explicitly investigate this brain structure-function relationship using two large independent cohorts of 176 and 236 young adults. Structural-MRI was performed to estimate the brain volume, and resting-state functional-MRI was applied to extract the amplitude of low-frequency fluctuations (ALFF), an imaging measure of intrinsic brain activity. Intriguingly, our results revealed a robust linear correlation between whole-brain size and ALFF. Moreover, specific brain lobes/regions, including the frontal lobe, the left middle frontal gyrus, anterior cingulate gyrus, Rolandic operculum, and insula, also showed a reliable, positive volume-ALFF correlation in the two cohorts. These findings offer direct, empirical evidence of a strong association between brain size/volume and intrinsic brain activity, as well as provide novel insight into the structural substrates of the intrinsic brain activity of the human brain. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. [Disturbed brain bioelectric activity in patients with liver encephalopathy and cirrhosis].

    Science.gov (United States)

    Alekseeva, A S; Beloborodova, E I; Rachkovskiĭ, M I; Filippova, L P; Lambrova, E G

    2009-01-01

    Brain bioelectric activity in 52 patients with liver cirrhosis (LC) was measured with respect to the degree of hepatic encephalopathy (HE) from the results of background and reactive EEG using West Haven criteria. As the severity of LC increased, signs of HE on background EEG appeared, index frequency and a-rhythm decreased and its amplitude increased. Reactive EEG was indicative of reduced duration, intensity, and decrement rate of responses to orientational loading (visual, somatosensorial, and auditory evoked potentials). It is concluded that EEG studies permit to predict dynamics of LC clinical course and may be used as an additional diagnostic tool, especially at the preclinical stage of HE.

  7. Sensory-evoked perturbations of locomotor activity by sparse sensory input: a computational study.

    Science.gov (United States)

    Bui, Tuan V; Brownstone, Robert M

    2015-04-01

    Sensory inputs from muscle, cutaneous, and joint afferents project to the spinal cord, where they are able to affect ongoing locomotor activity. Activation of sensory input can initiate or prolong bouts of locomotor activity depending on the identity of the sensory afferent activated and the timing of the activation within the locomotor cycle. However, the mechanisms by which afferent activity modifies locomotor rhythm and the distribution of sensory afferents to the spinal locomotor networks have not been determined. Considering the many sources of sensory inputs to the spinal cord, determining this distribution would provide insights into how sensory inputs are integrated to adjust ongoing locomotor activity. We asked whether a sparsely distributed set of sensory inputs could modify ongoing locomotor activity. To address this question, several computational models of locomotor central pattern generators (CPGs) that were mechanistically diverse and generated locomotor-like rhythmic activity were developed. We show that sensory inputs restricted to a small subset of the network neurons can perturb locomotor activity in the same manner as seen experimentally. Furthermore, we show that an architecture with sparse sensory input improves the capacity to gate sensory information by selectively modulating sensory channels. These data demonstrate that sensory input to rhythm-generating networks need not be extensively distributed. Copyright © 2015 the American Physiological Society.

  8. Brain Regions Associated to a Kinesthetic Illusion Evoked by Watching a Video of One's Own Moving Hand.

    Directory of Open Access Journals (Sweden)

    Fuminari Kaneko

    Full Text Available It is well known that kinesthetic illusions can be induced by stimulation of several sensory systems (proprioception, touch, vision…. In this study we investigated the cerebral network underlying a kinesthetic illusion induced by visual stimulation by using functional magnetic resonance imaging (fMRI in humans. Participants were instructed to keep their hand still while watching the video of their own moving hand (Self Hand or that of someone else's moving hand (Other Hand. In the Self Hand condition they experienced an illusory sensation that their hand was moving whereas the Other Hand condition did not induce any kinesthetic illusion. The contrast between the Self Hand and Other Hand conditions showed significant activation in the left dorsal and ventral premotor cortices, in the left Superior and Inferior Parietal lobules, at the right Occipito-Temporal junction as well as in bilateral Insula and Putamen. Most strikingly, there was no activation in the primary motor and somatosensory cortices, whilst previous studies have reported significant activation in these regions for vibration-induced kinesthetic illusions. To our knowledge, this is the first study that indicates that humans can experience kinesthetic perception without activation in the primary motor and somatosensory areas. We conclude that under some conditions watching a video of one's own moving hand could lead to activation of a network that is usually involved in processing copies of efference, thus leading to the illusory perception that the real hand is indeed moving.

  9. Brain Regions Associated to a Kinesthetic Illusion Evoked by Watching a Video of One's Own Moving Hand.

    Science.gov (United States)

    Kaneko, Fuminari; Blanchard, Caroline; Lebar, Nicolas; Nazarian, Bruno; Kavounoudias, Anne; Romaiguère, Patricia

    2015-01-01

    It is well known that kinesthetic illusions can be induced by stimulation of several sensory systems (proprioception, touch, vision…). In this study we investigated the cerebral network underlying a kinesthetic illusion induced by visual stimulation by using functional magnetic resonance imaging (fMRI) in humans. Participants were instructed to keep their hand still while watching the video of their own moving hand (Self Hand) or that of someone else's moving hand (Other Hand). In the Self Hand condition they experienced an illusory sensation that their hand was moving whereas the Other Hand condition did not induce any kinesthetic illusion. The contrast between the Self Hand and Other Hand conditions showed significant activation in the left dorsal and ventral premotor cortices, in the left Superior and Inferior Parietal lobules, at the right Occipito-Temporal junction as well as in bilateral Insula and Putamen. Most strikingly, there was no activation in the primary motor and somatosensory cortices, whilst previous studies have reported significant activation in these regions for vibration-induced kinesthetic illusions. To our knowledge, this is the first study that indicates that humans can experience kinesthetic perception without activation in the primary motor and somatosensory areas. We conclude that under some conditions watching a video of one's own moving hand could lead to activation of a network that is usually involved in processing copies of efference, thus leading to the illusory perception that the real hand is indeed moving.

  10. Pain-evoked trunk muscle activity changes during fatigue and DOMS

    DEFF Research Database (Denmark)

    Larsen, Lars Henrik; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2017-01-01

    BACKGROUND:Muscle pain may reorganize trunk muscle activity but interactions with exercise-related muscle fatigue and delayed onset muscle soreness (DOMS) is to be clarified.METHODS:In 19 healthy participants, the trunk muscle activity during 20 multi-directional unpredictable surface perturbatio...

  11. Characterization of the cerebral activity by time–frequency representation of evoked EEG potentials

    International Nuclear Information System (INIS)

    Clariá, Francesc; Vallverdú, Montserrat; Romero, Sergio; Caminal, Pere; Riba, Jordi; Barbanoj, Manuel J

    2011-01-01

    Event-related brain potentials (ERPs) are the electrical response of the brain while performing a particular task. Methods traditionally used to study ERPs measure the amplitude and duration of the waveform in order to quantify the changes, being signal morphology dependent. However, the frequency characteristics of those events remain uncovered. The aim of this work was the study of new measures to characterize, by means of time–frequency representation (TFR) techniques, the ERPs recorded while subjects conducted a choice reaction time task (Ericksen flanker task) following the administration of different alprazolam doses. Several measures defined from energy, instantaneous frequency and group delay functions were obtained by means of TFR techniques applied to the Choi–Williams distribution (CWD) of EEG signals. These measures, which are signal morphology independent, were studied in four frequency bands, δ (0–4 Hz), θ (4–8 Hz), α (8–15 Hz), β (15–30 Hz), and for certain time periods. Based on these measures, differences between ERPs were analyzed by comparing the different response types (successes or successfully corrected failures) of the subject performing the task, and comparing the applied drug doses. For each subject, the CWD of EEG signals was applied in two different ways: (a) all ERPs were averaged per channel, and then the CWD was applied; (b) the CWD was applied to each one of the ERPs. When the CWD was applied to each ERP, the energy measures in the δ, θ and β bands, the instantaneous frequency measures in the α and β bands, and the group delay measures in the δ, θ and α bands showed a statistically significant level p < 0.0005 in the analysis of the response type. Also, the energy measures in the θ and β bands and the instantaneous frequency measures in the α band showed statistically significant differences (p < 0.0005) between placebo and low and high drug doses. In contrast, poor results were obtained when all epochs of

  12. Evaluation of the evoked brain potentials of patients with asthenia and anxiety symptoms and the partial loss of sight

    Directory of Open Access Journals (Sweden)

    Tsira Abdryakhimova

    2017-03-01

    Full Text Available Background. Loss of sight, even partial, especially in adulthood, is accompanied by emotional, motivational and social consequences that directly affect the psychophysiological state of the individual himself, his communication in society and, often, the social status of the subject.  Methods. From the group of patients-volunteers (n=15 with a partial loss of sight of traumatic genesis two groups were formed for carrying out neurophysiological studies: with predominant asthenia and predominant anxiety. The controle group (CG constisted from patients of the same age (n=20 without psychiatric comorbidity. A study of acoustic event-related potentials of the brain (ERP was carried out in the oddball paradigm with the recording of the time and correctness of a simple sensorimotor reaction. Results. Comparative analysis of the asthenia group with the comparison group revealed a sufficient number of indicators of the ERP, which have significant statistical differences. The correctness of the sensorimotor reaction in this group was 98.3 ± 2.44%, whereas in the CG - 92.5 ± 5.74% (U [15; 20] = 62.5, p <0.01. The values of the amplitude of the early positivity of P1 in the asthenia group were 4.25 ± 3.312 μV, and in the CG -4.15 ± 7.933 μV (U [15, 20] = 50, p <0.001. The early negativity in that group was -2.78 ± 2.377 μV, and in the CG it was 10.55 ± 7.466 μV (U [15; 20] = 75; p <0.05.  Conclusion. In the asthenia group this is the correctness of the sensorimotor reaction and the amplitude of the components: P1, N1, P2, N2. In the anxiety group, such indicators were: latency period P1, intervals P1N1 and N2P3, amplitude swing P1N1. A specific marker of the asthenia group, distinguishing it from the CG, was the more positive values of the amplitude of the components P1, N1, P2, N2. Taking into account the low-frequency nature of the modulation of the amplitudes of these components (circa 2 Hz, it can be assumed that nonspecific brainstem

  13. Time to loss of brain function and activity during circulatory arrest.

    Science.gov (United States)

    Pana, R; Hornby, L; Shemie, S D; Dhanani, S; Teitelbaum, J

    2016-08-01

    Brain function during the dying process and around the time of cardiac arrest is poorly understood. To better inform the clinical physiology of the dying process and organ donation practices, we performed a scoping review of the literature to assess time to loss of brain function and activity after circulatory arrest. Medline and Embase databases were searched from inception to June 2014 for articles reporting the time interval to loss of brain function or activity after loss of systemic circulation. Thirty-nine studies met selection criteria. Seven human studies and 10 animal studies reported that electroencephalography (EEG) activity is lost less than 30seconds after abrupt circulatory arrest. In the setting of existing brain injury, with progressive loss of oxygenated circulation, loss of EEG may occur before circulatory arrest. Cortical evoked potentials may persist for several minutes after loss of circulation. The time required to lose brain function varied according to clinical context and method by which this function is measured. Most studies show that clinical loss of consciousness and loss of EEG activity occur within 30seconds after abrupt circulatory arrest and may occur before circulatory arrest after progressive hypoxia-ischemia. Prospective clinical studies are required to confirm these observations. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    isoform compositions of the Na(+)/K(+)-ATPase remain unresolved. The various cell types in the brain serve a certain temporal contribution in the face of network activity; astrocytes respond directly to the immediate release of K(+) from neurons, whereas the neurons themselves become the primary K......During neuronal activity in the brain, extracellular K(+) rises and is subsequently removed to prevent a widespread depolarization. One of the key players in regulating extracellular K(+) is the Na(+)/K(+)-ATPase, although the relative involvement and physiological impact of the different subunit......(+) absorbers as activity ends. The kinetic characteristics of the catalytic α subunit isoforms of the Na(+)/K(+)-ATPase are, partly, determined by the accessory β subunit with which they combine. The isoform combinations expressed by astrocytes and neurons, respectively, appear to be in line with the kinetic...

  15. The Sum of Its Parts—Effects of Gastric Distention, Nutrient Content and Sensory Stimulation on Brain Activation

    Science.gov (United States)

    Spetter, Maartje S.; de Graaf, Cees; Mars, Monica; Viergever, Max A.; Smeets, Paul A. M.

    2014-01-01

    During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to assess the effect of gastric distention with an intra-gastric load and the additional effect of oral stimulation on brain activity after food administration. Our secondary objective was to study the correlations between hormone responses and appetite-related ratings and brain activation. Fourteen men completed three functional magnetic resonance imaging sessions during which they either received a naso-gastric infusion of water (stomach distention), naso-gastric infusion of chocolate milk (stomach distention + nutrients), or ingested chocolate-milk (stomach distention + nutrients + oral exposure). Appetite ratings and blood parameters were measured at several time points. During gastric infusion, brain activation was observed in the midbrain, amygdala, hypothalamus, and hippocampus for both chocolate milk and water, i.e., irrespective of nutrient content. The thalamus, amygdala, putamen and precuneus were activated more after ingestion than after gastric infusion of chocolate milk, whereas infusion evoked greater activation in the hippocampus and anterior cingulate. Moreover, areas involved in gustation and reward were activated more after oral stimulation. Only insulin responses following naso-gastric infusion of chocolate milk correlated with brain activation, namely in the putamen and insula. In conclusion, we show that normal (oral) food ingestion evokes greater activation than gastric infusion in stomach distention and food intake-related brain areas. This provides neural

  16. The sum of its parts--effects of gastric distention, nutrient content and sensory stimulation on brain activation.

    Directory of Open Access Journals (Sweden)

    Maartje S Spetter

    Full Text Available During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to assess the effect of gastric distention with an intra-gastric load and the additional effect of oral stimulation on brain activity after food administration. Our secondary objective was to study the correlations between hormone responses and appetite-related ratings and brain activation. Fourteen men completed three functional magnetic resonance imaging sessions during which they either received a naso-gastric infusion of water (stomach distention, naso-gastric infusion of chocolate milk (stomach distention + nutrients, or ingested chocolate-milk (stomach distention + nutrients + oral exposure. Appetite ratings and blood parameters were measured at several time points. During gastric infusion, brain activation was observed in the midbrain, amygdala, hypothalamus, and hippocampus for both chocolate milk and water, i.e., irrespective of nutrient content. The thalamus, amygdala, putamen and precuneus were activated more after ingestion than after gastric infusion of chocolate milk, whereas infusion evoked greater activation in the hippocampus and anterior cingulate. Moreover, areas involved in gustation and reward were activated more after oral stimulation. Only insulin responses following naso-gastric infusion of chocolate milk correlated with brain activation, namely in the putamen and insula. In conclusion, we show that normal (oral food ingestion evokes greater activation than gastric infusion in stomach distention and food intake-related brain areas. This

  17. The sum of its parts--effects of gastric distention, nutrient content and sensory stimulation on brain activation.

    Science.gov (United States)

    Spetter, Maartje S; de Graaf, Cees; Mars, Monica; Viergever, Max A; Smeets, Paul A M

    2014-01-01

    During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to assess the effect of gastric distention with an intra-gastric load and the additional effect of oral stimulation on brain activity after food administration. Our secondary objective was to study the correlations between hormone responses and appetite-related ratings and brain activation. Fourteen men completed three functional magnetic resonance imaging sessions during which they either received a naso-gastric infusion of water (stomach distention), naso-gastric infusion of chocolate milk (stomach distention + nutrients), or ingested chocolate-milk (stomach distention + nutrients + oral exposure). Appetite ratings and blood parameters were measured at several time points. During gastric infusion, brain activation was observed in the midbrain, amygdala, hypothalamus, and hippocampus for both chocolate milk and water, i.e., irrespective of nutrient content. The thalamus, amygdala, putamen and precuneus were activated more after ingestion than after gastric infusion of chocolate milk, whereas infusion evoked greater activation in the hippocampus and anterior cingulate. Moreover, areas involved in gustation and reward were activated more after oral stimulation. Only insulin responses following naso-gastric infusion of chocolate milk correlated with brain activation, namely in the putamen and insula. In conclusion, we show that normal (oral) food ingestion evokes greater activation than gastric infusion in stomach distention and food intake-related brain areas. This provides neural

  18. Estradiol suppresses ingestive response evoked by activation of 5-HT1A receptors in the lateral hypothalamus of ovariectomized rats.

    Science.gov (United States)

    Taschetto, Ana P D; Levone, Brunno R; Kochenborger, Larissa; da Silva, Eduardo S; Flores, Rafael A; Faria, Moacir S; Paschoalini, Marta A

    2018-03-08

    The present study investigated the effects of estradiol (E2) on ingestive behavior after activation of 5-HT1A receptors in the lateral hypothalamus (LH) of female rats habituated to eat a wet mash diet. Ovariectomized rats treated with corn oil (OVX) or estradiol cypionate (OVX+E) received local injections into the LH of vehicle or an agonist of 5-HT1A receptors, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT; at a dose of 6 nmol). To determine the involvement of these receptors in food intake, some animals were pretreated with N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide maleate (WAY-100635, a 5-HT1A receptor full antagonist, at a dose of 0.37 nmol), followed by the injection of the agonist 8-OH-DPAT or its vehicle. The results showed that the injection of 8-OH-DPAT into the LH of OVX rats significantly increased food intake, and the duration and frequency of this behavior. The pretreatment with E2 suppressed the hyperphagic response induced by 8-OH-DPAT in OVX animals. The inhibition of 5-HT1A receptors after pretreatment with WAY-100635 blocked the hyperphagic effects evoked by 8-OH-DPAT in OVX. These results indicate that the activity of LH 5-HT1A receptors could be affected by blood E2 levels.

  19. Bayesian Inference for Neural Electromagnetic Source Localization: Analysis of MEG Visual Evoked Activity

    International Nuclear Information System (INIS)

    George, J.S.; Schmidt, D.M.; Wood, C.C.

    1999-01-01

    We have developed a Bayesian approach to the analysis of neural electromagnetic (MEG/EEG) data that can incorporate or fuse information from other imaging modalities and addresses the ill-posed inverse problem by sarnpliig the many different solutions which could have produced the given data. From these samples one can draw probabilistic inferences about regions of activation. Our source model assumes a variable number of variable size cortical regions of stimulus-correlated activity. An active region consists of locations on the cortical surf ace, within a sphere centered on some location in cortex. The number and radi of active regions can vary to defined maximum values. The goal of the analysis is to determine the posterior probability distribution for the set of parameters that govern the number, location, and extent of active regions. Markov Chain Monte Carlo is used to generate a large sample of sets of parameters distributed according to the posterior distribution. This sample is representative of the many different source distributions that could account for given data, and allows identification of probable (i.e. consistent) features across solutions. Examples of the use of this analysis technique with both simulated and empirical MEG data are presented

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

    Science.gov (United States)

    Luo, Zhongchi; Pan, Yingtian; Du, Congwu

    2012-02-01

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

  1. Entrainment pattern between sympathetic and phrenic nerve activities in the Sprague-Dawley rat: hypoxia-evoked sympathetic activity during expiration.

    Science.gov (United States)

    Dick, Thomas E; Hsieh, Y-H; Morrison, Shaun; Coles, Sharon K; Prabhakar, Nanduri

    2004-06-01

    Sympathetic and respiratory motor activities are entrained centrally. We hypothesize that this coupling may partially underlie changes in sympathetic activity evoked by hypoxia due to activity-dependent changes in the respiratory pattern. Specifically, we tested the hypothesis that sympathetic nerve activity (SNA) expresses a short-term potentiation in activity after hypoxia similar to that expressed in phrenic nerve activity (PNA). Adult male, Sprague-Dawley (Zivic Miller) rats (n = 19) were anesthetized (Equithesin), vagotomized, paralyzed, ventilated, and pneumothoracotomized. We recorded PNA and splanchnic SNA (sSNA) and generated cycle-triggered averages (CTAs) of rectified and integrated sSNA before, during, and after exposures to hypoxia (8% O(2) and 92% N(2) for 45 s). Inspiration (I) and expiration (E) were divided in half, and the average and area of integrated sSNA were calculated and compared at the following time points: before hypoxia, at the peak breathing frequency during hypoxia, immediately before the end of hypoxia, immediately after hypoxia, and 60 s after hypoxia. In our animal model, sSNA bursts consistently followed the I-E phase transition. With hypoxia, sSNA increased in both halves of E, but preferentially in the second rather than the first half of E, and decreased in I. After hypoxia, sSNA decreased abruptly, but the coefficient of variation in respiratory modulation of sSNA was significantly less than that at baseline. The hypoxic-evoked changes in sympathetic activity and respiratory pattern resulted in sSNA in the first half of E being correlated negatively to that in the second half of E (r = -0.65, P hypoxia, the variability in the entrainment pattern had returned to baseline. The preferential recruitment of late expiratory sSNA during hypoxia results from either activation by expiratory-modulated neurons or by non-modulated neurons whose excitatory drive is not gated during late E.

  2. 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.

  3. fMRI activation during spike and wave discharges evoked by photic stimulation

    DEFF Research Database (Denmark)

    Moeller, Friederike; Siebner, Hartwig R; Ahlgrimm, Nils

    2009-01-01

    Photoparoxysmal response (PPR) is an electroencephalographic (EEG) trait characterized by the occurrence of epileptiform discharges in response to visual stimulation. Studying this trait helps to learn about mechanisms of epileptogenicity. While simultaneous recordings of EEG and functional MRI...... intermittent photic stimulation (IPS) in a 3 T MR scanner. PPR was elicited in 6 subjects, four diagnosed with idiopathic generalised epilepsy and two with tension-type headache. Because PPR is preceded by synchronization of cortical gamma oscillations, blood oxygenation level-dependent (BOLD) signal changes...... were analysed at the onset of the PPR (standard regressor) and 3 s before the onset of PPR (early regressor) in one model. In all subjects, IPS led to a significant activation of the visual cortex. Based on the early regressor, PPR associated activation was found in the parietal cortex adjacent...

  4. Pain-evoked trunk muscle activity changes during fatigue and DOMS

    DEFF Research Database (Denmark)

    Larsen, Lars Henrik; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2017-01-01

    BACKGROUND:Muscle pain may reorganize trunk muscle activity but interactions with exercise-related muscle fatigue and delayed onset muscle soreness (DOMS) is to be clarified.METHODS:In 19 healthy participants, the trunk muscle activity during 20 multi-directional unpredictable surface perturbations...... were recorded after bilateral isotonic saline injections (control) and during unilateral and bilateral hypertonic saline-induced low back pain (LBP) in conditions of back muscle fatigue (Day-1) and DOMS (Day-2). Pain intensity and distribution were assessed by visual analogue scale (VAS) scores...... and pain drawings. The degree of fatigue and DOMS were assessed by Likert scale scores. Root-mean-square electromyographic (RMS-EMG) signals were recorded post-perturbation from six bilateral trunk muscles and the difference from baseline conditions (Delta-RMS-EMG) was extracted and averaged across...

  5. Pain-evoked trunk muscle activity changes during fatigue and DOMS.

    Science.gov (United States)

    Larsen, L H; Hirata, R P; Graven-Nielsen, T

    2017-05-01

    Muscle pain may reorganize trunk muscle activity but interactions with exercise-related muscle fatigue and delayed onset muscle soreness (DOMS) is to be clarified. In 19 healthy participants, the trunk muscle activity during 20 multi-directional unpredictable surface perturbations were recorded after bilateral isotonic saline injections (control) and during unilateral and bilateral hypertonic saline-induced low back pain (LBP) in conditions of back muscle fatigue (Day-1) and DOMS (Day-2). Pain intensity and distribution were assessed by visual analogue scale (VAS) scores and pain drawings. The degree of fatigue and DOMS were assessed by Likert scale scores. Root-mean-square electromyographic (RMS-EMG) signals were recorded post-perturbation from six bilateral trunk muscles and the difference from baseline conditions (Delta-RMS-EMG) was extracted and averaged across abdominal and back muscles. In DOMS, peak VAS scores were higher during bilateral control and bilateral saline-induced pain than fatigue (p fatigue (p fatigue and DOMS, the back muscle Delta-RMS-EMG increased during bilateral compared with unilateral pain and control injections (p fatigue, the post-perturbation Delta-RMS-EMG in back muscles was higher during bilateral pain and lower during unilateral pain (p muscle responses to surface perturbations in bilateral and unilateral LBP, respectively, was more expressed during exercise-induced back muscle soreness compared with fatigue. Back muscle activity decreased during unilateral and increased during bilateral pain after unpredictable surface perturbations during muscle fatigue and DOMS. Accumulation effects of DOMS on pain intensity and spreading and trunk muscle activity after pain-induction. © 2017 European Pain Federation - EFIC®.

  6. Electrophysiological study in the infraorbital nerve of the rat: Spontaneous and evoked activity

    Energy Technology Data Exchange (ETDEWEB)

    AlbarracIn, A L [Catedra de Neurociencias, Facultad de Medicina, Universidad Nacional de Tucuman, Av. Roca 2200, PC 4000 (Argentina); Farfan, F D [Departamento de BioingenierIa, FACET, Universidad Nacional de Tucuman, INSIBIO - CONICET, CC 327, PC 4000 (Argentina); Felice, C J [Departamento de BioingenierIa, FACET, Universidad Nacional de Tucuman, INSIBIO - CONICET, CC 327, PC 4000 (Argentina)

    2007-11-15

    In this work we present some studies in the afferent nerve of the rat vibrissae. Studies on spontaneous activity (SA) in this sensorial system are of long data. Nevertheless, SA recordings in the nerve of a single vibrissa have not been made until present. In this work, we use an algorithm based on signal decomposition with Continuous Wavelet Transform (CWT) to analyse the discharges of two nerves. The action potentials of both nerves were detected and the firing rates were calculated. These results suggest that the firing rate of one vibrissa innervation is low considering that this nerve contains hundred of fibers. In addition, we present preliminary studies suggesting important effects of the hair shaft length in the afferent discharge during the vibrissae movements. The experiments consisted in recording the nerve activity after the vibrissae were sectioned at two different levels. The results showed important differences in the signal energy contents. It suggests that the hair shaft length would produce a differential activation of the mechanoreceptors located in the vibrissae follicle.

  7. Heterosynaptic modulation of evoked synaptic potentials in layer II of the entorhinal cortex by activation of the parasubiculum.

    Science.gov (United States)

    Sparks, Daniel W; Chapman, C Andrew

    2016-08-01

    The superficial layers of the entorhinal cortex receive sensory and associational cortical inputs and provide the hippocampus with the majority of its cortical sensory input. The parasubiculum, which receives input from multiple hippocampal subfields, sends its single major output projection to layer II of the entorhinal cortex, suggesting that it may modulate processing of synaptic inputs to the entorhinal cortex. Indeed, stimulation of the parasubiculum can enhance entorhinal responses to synaptic input from the piriform cortex in vivo. Theta EEG activity contributes to spatial and mnemonic processes in this region, and the current study assessed how stimulation of the parasubiculum with either single pulses or short, five-pulse, theta-frequency trains may modulate synaptic responses in layer II entorhinal stellate neurons evoked by stimulation of layer I afferents in vitro. Parasubicular stimulation pulses or trains suppressed responses to layer I stimulation at intervals of 5 ms, and parasubicular stimulation trains facilitated layer I responses at a train-pulse interval of 25 ms. This suggests that firing of parasubicular neurons during theta activity may heterosynaptically enhance incoming sensory inputs to the entorhinal cortex. Bath application of the hyperpolarization-activated cation current (Ih) blocker ZD7288 enhanced the facilitation effect, suggesting that cholinergic inhibition of Ih may contribute. In addition, repetitive pairing of parasubicular trains and layer I stimulation induced a lasting depression of entorhinal responses to layer I stimulation. These findings provide evidence that theta activity in the parasubiculum may promote heterosynaptic modulation effects that may alter sensory processing in the entorhinal cortex. Copyright © 2016 the American Physiological Society.

  8. Comparative investigation of stimulus-evoked rod outer segment movement and retinal electrophysiological activity

    Science.gov (United States)

    Lu, Yiming; Wang, Benquan; Yao, Xincheng

    2017-02-01

    Transient retinal phototropism (TRP) has been observed in rod photoreceptors activated by oblique visible light flashes. Time-lapse confocal microscopy and optical coherence tomography (OCT) revealed rod outer segment (ROS) movements as the physical source of TRP. However, the physiological source of TRP is still not well understood. In this study, concurrent TRP and electroretinogram (ERG) measurements disclosed a remarkably earlier onset time of the ROS movements (treatment reversibly blocked the photoreceptor ERG a-wave, which is known to reflect hyperpolarization of retinal photoreceptors, but preserved the TRP associated rod OS movements well. Our experimental results and theoretical analysis suggested that the physiological source of TRP might be attributed to early stages of phototransduction, before the hyperpolarization of retinal photoreceptors.

  9. Sound-Evoked Activity Influences Myelination of Brainstem Axons in the Trapezoid Body.

    Science.gov (United States)

    Sinclair, James L; Fischl, Matthew J; Alexandrova, Olga; Heβ, Martin; Grothe, Benedikt; Leibold, Christian; Kopp-Scheinpflug, Conny

    2017-08-23

    Plasticity of myelination represents a mechanism to tune the flow of information by balancing functional requirements with metabolic and spatial constraints. The auditory system is heavily myelinated and operates at the upper limits of action potential generation frequency and speed observed in the mammalian CNS. This study aimed to characterize the development of myelin within the trapezoid body, a central auditory fiber tract, and determine the influence sensory experience has on this process in mice of both sexes. We find that in vitro conduction speed doubles following hearing onset and the ability to support high-frequency firing increases concurrently. Also in this time, the diameter of trapezoid body axons and the thickness of myelin double, reaching mature-like thickness between 25 and 35 d of age. Earplugs were used to induce ∼50 dB elevation in auditory thresholds. If introduced at hearing onset, trapezoid body fibers developed thinner axons and myelin than age-matched controls. If plugged during adulthood, the thickest trapezoid body fibers also showed a decrease in myelin. These data demonstrate the need for sensory activity in both development and maintenance of myelin and have important implications in the study of myelin plasticity and how this could relate to sensorineural hearing loss following peripheral impairment. SIGNIFICANCE STATEMENT The auditory system has many mechanisms to maximize the dynamic range of its afferent fibers, which operate at the physiological limit of action potential generation, precision, and speed. In this study we demonstrate for the first time that changes in peripheral activity modifies the thickness of myelin in sensory neurons, not only in development but also in mature animals. The current study suggests that changes in CNS myelination occur as a downstream mechanism following peripheral deficit. Given the required submillisecond temporal precision for binaural auditory processing, reduced myelination might

  10. Bradykinin Contributes to Sympathetic and Pressor Responses Evoked by Activation of Skeletal Muscle Afferents P2X in Heart Failure

    Directory of Open Access Journals (Sweden)

    Jihong Xing

    2016-11-01

    Full Text Available Background/Aims: Published data suggest that purinergic P2X receptors of muscle afferent nerves contribute to the enhanced sympathetic nervous activity (SNA and blood pressure (BP responses during static exercise in heart failure (HF. In this study, we examined engagement of bradykinin (BK in regulating responses of SNA and BP evoked by P2X stimulation in rats with HF. We further examined cellular mechanisms responsible for BK. We hypothesized that BK potentiates P2X currents of muscle dorsal root ganglion (DRG neurons, and this effect is greater in HF due to upregulation of BK kinin B2 and P2X3 receptor. As a result, BK amplifies muscle afferents P2X-mediated SNA and BP responses. Methods: Renal SNA and BP responses were recorded in control rats and rats with HF. Western Blot analysis and patch-clamp methods were employed to examine the receptor expression and function of DRG neurons involved in the effects of BK. Results: BK injected into the arterial blood supply of the hindlimb muscles heightened the reflex SNA and BP responses induced by P2X activation with α,β-methylene ATP to a greater degree in HF rats. In addition, HF upregulated the protein expression of kinin B2 and P2X3 in DRG and the prior application of BK increased the magnitude of α,β-methylene ATP-induced currents in muscle DRG neurons from HF rats. Conclusion: BK plays a facilitating role in modulating muscle afferent P2X-engaged reflex sympathetic and pressor responses. In HF, P2X responsivness is augmented due to increases in expression of kinin B2 and P2X3 receptors and P2X current activity.

  11. Using Brain Electrical Activity Mapping to Diagnose Learning Disabilities.

    Science.gov (United States)

    Torello, Michael, W.; Duffy, Frank H.

    1985-01-01

    Cognitive neuroscience assumes that measurement of brain electrical activity should relate to cognition. Brain Electrical Activity Mapping (BEAM), a non-invasive technique, is used to record changes in activity from one brain area to another and is 80 to 90 percent successful in classifying subjects as dyslexic or normal. (MT)

  12. Influence of denture treatment on brain function activity

    Directory of Open Access Journals (Sweden)

    Toshio Hosoi

    2011-02-01

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

  13. A review of alpha activity in integrative brain function: fundamental physiology, sensory coding, cognition and pathology.

    Science.gov (United States)

    Başar, Erol

    2012-10-01

    Questions related to the genesis and functional correlates of the brain's alpha oscillations around 10Hz (Alpha) are one of the fundamental research areas in neuroscience. In recent decades, analysis of this activity has been not only the focus of interest for description of sensory-cognitive processes, but has also led to trials for establishing new hypotheses. The present review and the companion review aim to constitute an ensemble of "reasonings and suggestions" to understand alpha oscillations based on a wide range of accumulated findings rather than a trial to launch a new "alpha theory". The review starts with descriptions of earlier extracellular recordings, field potentials and also considers earlier alpha hypotheses. Analytical descriptions of evoked and event-related responses, event-related desynchronization, the relationship between spontaneous activity and evoked potentials, aging brain, pathology and alpha response in cognitive impairment are in the content of this review. In essence, the gamut of the survey includes a multiplicity of evidence on functional correlates in sensory processing, cognition, memory and vegetative system, including the spinal cord and heart. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Brain activity modifications following spinal cord stimulation for chronic neuropathic pain: A systematic review.

    Science.gov (United States)

    Bentley, L D; Duarte, R V; Furlong, P L; Ashford, R L; Raphael, J H

    2016-04-01

    Spinal cord stimulation (SCS) is believed to exert supraspinal effects; however, these mechanisms are still far from fully elucidated. This systematic review aims to assess existing neurophysiological and functional neuroimaging literature to reveal current knowledge regarding the effects of SCS for chronic neuropathic pain on brain activity, to identify gaps in knowledge, and to suggest directions for future research. Electronic databases and hand-search of reference lists were employed to identify publications investigating brain activity associated with SCS in patients with chronic neuropathic pain, using neurophysiological and functional neuroimaging techniques (fMRI, PET, MEG, EEG). Studies investigating patients with SCS for chronic neuropathic pain and studying brain activity related to SCS were included. Demographic data (age, gender), study factors (imaging modality, patient diagnoses, pain area, duration of SCS at recording, stimulus used) and brain areas activated were extracted from the included studies. Twenty-four studies were included. Thirteen studies used neuroelectrical imaging techniques, eight studies used haemodynamic imaging techniques, two studies employed both neuroelectrical and haemodynamic techniques separately, and one study investigated cerebral neurobiology. The limited available evidence regarding supraspinal mechanisms of SCS does not allow us to develop any conclusive theories. However, the studies included appear to show an inhibitory effect of SCS on somatosensory evoked potentials, as well as identifying the thalamus and anterior cingulate cortex as potential mediators of the pain experience. The lack of substantial evidence in this area highlights the need for large-scale controlled studies of this kind. © 2015 European Pain Federation - EFIC®

  15. Auditory evoked field measurement using magneto-impedance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K., E-mail: o-kabou@echo.nuee.nagoya-u.ac.jp; Tajima, S.; Song, D.; Uchiyama, T. [Graduate School of Engineering, Nagoya University, Nagoya (Japan); Hamada, N.; Cai, C. [Aichi Steel Corporation, Tokai (Japan)

    2015-05-07

    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement.

  16. An allosteric regulator of R7-RGS proteins influences light-evoked activity and glutamatergic waves in the inner retina.

    Directory of Open Access Journals (Sweden)

    Matthew D Cain

    Full Text Available In the outer retina, G protein-coupled receptor (GPCR signaling mediates phototransduction and synaptic transmission between photoreceptors and ON bipolar cells. In contrast, the functions of modulatory GPCR signaling networks in the inner retina are less well understood. We addressed this question by determining the consequences of augmenting modulatory Gi/o signaling driven by endogenous transmitters. This was done by analyzing the effects of genetically ablating the R7 RGS-binding protein (R7BP, a membrane-targeting protein and positive allosteric modulator of R7-RGS (regulator of the G protein signaling 7 family that deactivates Gi/oα subunits. We found that R7BP is expressed highly in starburst amacrine cells and retinal ganglion cells (RGCs. As indicated by electroretinography and multielectrode array recordings of adult retina, ablation of R7BP preserved outer retina function, but altered the firing rate and latency of ON RGCs driven by rods and cones but not rods alone. In developing retina, R7BP ablation increased the burst duration of glutamatergic waves whereas cholinergic waves were unaffected. This effect on glutamatergic waves did not result in impaired segregation of RGC projections to eye-specific domains of the dorsal lateral geniculate nucleus. R7BP knockout mice exhibited normal spatial contrast sensitivity and visual acuity as assessed by optomotor reflexes. Taken together these findings indicate that R7BP-dependent regulation of R7-RGS proteins shapes specific aspects of light-evoked and spontaneous activity of RGCs in mature and developing retina.

  17. An allosteric regulator of R7-RGS proteins influences light-evoked activity and glutamatergic waves in the inner retina.

    Science.gov (United States)

    Cain, Matthew D; Vo, Bradly Q; Kolesnikov, Alexander V; Kefalov, Vladimir J; Culican, Susan M; Kerschensteiner, Daniel; Blumer, Kendall J

    2013-01-01

    In the outer retina, G protein-coupled receptor (GPCR) signaling mediates phototransduction and synaptic transmission between photoreceptors and ON bipolar cells. In contrast, the functions of modulatory GPCR signaling networks in the inner retina are less well understood. We addressed this question by determining the consequences of augmenting modulatory Gi/o signaling driven by endogenous transmitters. This was done by analyzing the effects of genetically ablating the R7 RGS-binding protein (R7BP), a membrane-targeting protein and positive allosteric modulator of R7-RGS (regulator of the G protein signaling 7) family that deactivates Gi/oα subunits. We found that R7BP is expressed highly in starburst amacrine cells and retinal ganglion cells (RGCs). As indicated by electroretinography and multielectrode array recordings of adult retina, ablation of R7BP preserved outer retina function, but altered the firing rate and latency of ON RGCs driven by rods and cones but not rods alone. In developing retina, R7BP ablation increased the burst duration of glutamatergic waves whereas cholinergic waves were unaffected. This effect on glutamatergic waves did not result in impaired segregation of RGC projections to eye-specific domains of the dorsal lateral geniculate nucleus. R7BP knockout mice exhibited normal spatial contrast sensitivity and visual acuity as assessed by optomotor reflexes. Taken together these findings indicate that R7BP-dependent regulation of R7-RGS proteins shapes specific aspects of light-evoked and spontaneous activity of RGCs in mature and developing retina.

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

    Science.gov (United States)

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

    2015-08-01

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

  19. Brain mapping of median nerve somatosensory evoked potential with combined {sup 99m}Tc-ECD single-photon emission tomography and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zifko, U.A. [Dept. of Clinical Neurological Sciences, Victoria Hospital, Univ. of Western Ontario, London, ON (Canada); Slomka, P.J. [Dept. of Diagnostic Radiology and Nuclear Medicine, Victoria Hospital, Univ. of Western Ontario, London, ON (Canada); Young, G.B. [Dept. of Clinical Neurological Sciences, Victoria Hospital, Univ. of Western Ontario, London, ON (Canada); Reid, R.H. [Dept. of Diagnostic Radiology and Nuclear Medicine, Victoria Hospital, Univ. of Western Ontario, London, ON (Canada); Bolton, C.F. [Dept. of Clinical Neurological Sciences, Victoria Hospital, Univ. of Western Ontario, London, ON (Canada)

    1996-05-01

    Single-photon emission tomography (SPET) was performed during electrical median nerve stimulation and used to detect focal neuronal activation in the somatosensory pathways. Intravenously administered technetium-99m ethyl cysteinate dimer (ECD) was used as a blood flow tracer to obtain baseline and activated images in each of three subjects. After image registration, baseline images were compared voxel by voxel with the activation images. In addition, the mean summation of the activated-state images of the subjects was compared with the mean summation of the baseline-state images of ten normal subjects. Discrete brain regions occupying 0.9%-1.6% of total brain volume showed an increase in signal from 33.6% to 35.0%. For further anatomical localization of regional increases in signal, the MRI scan of each subject was registered and superimposed on the activated-state SPET image. This method may be used to localize lesions in various disorders of the central nervous system. (orig.)

  20. The brain smell centres - comparison of localisation and activation in male and female subjects using functional MR imaging

    International Nuclear Information System (INIS)

    Marchwicka-Wasiak, M.; Goraj, B.

    2004-01-01

    The study was conducted in order to determine and to compare the location and activation of smell brain centres in females and males brains using olfactory nerve-mediated (geraniol) and combined olfactory and trigeminal nerve-mediated (patchouli) stimulants. 10 normal volunteers (five women and five men), right-handed, non-smokers, without any CNS diseases were examined to determine the activated cortex areas during stimulation by geraniol and patchouli. MR brain scans were obtained using a 1.5 T clinical scanner, with the head-neck coil. The imaging was performed in each subject using SE and EPI sequences with a blood-oxygen-level-dependent (BOLD) effect. The individual inhaled odorized air during the 30 seconds period and alternating room air over the same period. The mean pixel intensity of activated images was substracted from the mean pixel intensity of preactivated images. The olfactory system-mediated stimuli (geraniol) evoked bilateral activation of female brains smell centres and right hemisphere centres activation in male brains. The exposure to the olfactory and trigeminal nerve-mediated stimuli (patchouli) showed more activated regions in both sexes than to the olfactory nerve-ediated stimuli. fMRI proved to be a useful method to compare the location and activation of male and female brain smell centres. (author)

  1. Altered Coupling between Motion-Related Activation and Resting-State Brain Activity in the Ipsilesional Sensorimotor Cortex after Cerebral Stroke

    Directory of Open Access Journals (Sweden)

    Jianping Hu

    2017-07-01

    Full Text Available Functional connectivity maps using resting-state functional magnetic resonance imaging (rs-fMRI can closely resemble task fMRI activation patterns, suggesting that resting-state brain activity may predict task-evoked activation or behavioral performance. However, this conclusion was mostly drawn upon a healthy population. It remains unclear whether the predictive ability of resting-state brain activity for task-evoked activation would change under different pathological conditions. This study investigated dynamic changes of coupling between patterns of resting-state functional connectivity (RSFC and motion-related activation in different stages of cerebral stroke. Twenty stroke patients with hand motor function impairment were involved. rs-fMRI and hand motion-related fMRI data were acquired in the acute, subacute, and early chronic stages of cerebral stroke on a 3-T magnetic resonance (MR scanner. Sixteen healthy participants were enrolled as controls. For each subject, an activation map of the affected hand was first created using general linear model analysis on task fMRI data, and then an RSFC map was determined by seeding at the peak region of hand motion activation during the intact hand task. We then measured the extent of coupling between the RSFC maps and motion-related activation maps. Dynamic changes of the coupling between the two fMRI maps were estimated using one-way repeated measures analysis of variance across the three stages. Moreover, imaging parameters were correlated with motor performances. Data analysis showed that there were different coupling patterns between motion-related activation and RSFC maps associating with the affected motor regions during the acute, subacute, and early chronic stages of stroke. Coupling strengths increased as the recovery from stroke progressed. Coupling strengths were correlated with hand motion performance in the acute stage, while coupling recovery was negatively correlated with the recovery

  2. In vivo imaging of brain metabolism activity using a phosphorescent oxygen-sensitive probe

    Science.gov (United States)

    Tsytsarev, Vassiliy; Arakawa, Hiroyuki; Borisov, Sergei; Pumbo, Elena; Erzurumlu, Reha S.; Papkovsky, Dmitri B.

    2013-01-01

    Several approaches have been adopted for real-time imaging of neural activity in vivo. We tested a new cell-penetrating phosphorescent oxygen-sensitive probe, NanO2-IR, to monitor temporal and spatial dynamics of oxygen metabolism in the neocortex following peripheral sensory stimulation. Probe solution was applied to the surface of anesthetized mouse brain; optical imaging was performed using a MiCAM-02 system. Trains of whisker stimuli were delivered and associated changes in phosphorescent signal were recorded in the contralateral somatosensory (“barrel”) cortex. Sensory stimulation led to changes in oxygenation of activated areas of the barrel cortex. The oxygen imaging results were compared to those produced by the voltage-sensitive dye RH-1691. While the signals emitted by the two probes differed in shape and amplitude, they both faithfully indicated specific whisker evoked cortical activity. Thus, NanO2-IR probe can be used as a tool in visualization and realtime analysis of sensory- evoked neural activity in vivo. PMID:23624034

  3. Evoked Electrical and Cerebral Vascular Responses Following Sleep Deprivation

    Science.gov (United States)

    Schei, Jennifer L.; Rector, David M.

    2011-01-01

    Neuronal activity elicits vascular dilation, delivering additional blood and metabolites to the activated region. With increasing neural activity, vessels stretch and may become less compliant. Most functional imaging studies assume that limits to vascular expansion are not normally reached except under pathological conditions, with the possibility that metabolism could outpace supply. However, we previously demonstrated that evoked hemodynamic responses were larger during quiet sleep when compared to both waking and REM sleep, suggesting that high basal activity during wake may elicit blunted evoked hemodynamic responses due to vascular expansion limits. We hypothesized that extended brain activity through sleep deprivation will further dilate blood vessels, and exacerbate the blunted evoked hemodynamic responses observed during wake, and dampen responses in subsequent sleep. We measured evoked electrical and hemodynamic responses from rats using auditory clicks (0.5 s, 10 Hz, 2–13 s random ISIs) for one hour following 2, 4, or 6 hours of sleep deprivation. Time-of-day matched controls were recorded continuously for 7 hours. Within quiet sleep periods following deprivation, ERP amplitude did not differ; however, the evoked vascular response was smaller with longer sleep deprivation periods. These results suggest that prolonged neural activity periods 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 sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma. PMID:21854966

  4. Neural Activity Patterns in the Human Brain Reflect Tactile Stickiness Perception

    Science.gov (United States)

    Kim, Junsuk; Yeon, Jiwon; Ryu, Jaekyun; Park, Jang-Yeon; Chung, Soon-Cheol; Kim, Sung-Phil

    2017-01-01

    Our previous human fMRI study found brain activations correlated with tactile stickiness perception using the uni-variate general linear model (GLM) (Yeon et al., 2017). Here, we conducted an in-depth investigation on neural correlates of sticky sensations by employing a multivoxel pattern analysis (MVPA) on the same dataset. In particular, we statistically compared multi-variate neural activities in response to the three groups of sticky stimuli: A supra-threshold group including a set of sticky stimuli that evoked vivid sticky perception; an infra-threshold group including another set of sticky stimuli that barely evoked sticky perception; and a sham group including acrylic stimuli with no physically sticky property. Searchlight MVPAs were performed to search for local activity patterns carrying neural information of stickiness perception. Similar to the uni-variate GLM results, significant multi-variate neural activity patterns were identified in postcentral gyrus, subcortical (basal ganglia and thalamus), and insula areas (insula and adjacent areas). Moreover, MVPAs revealed that activity patterns in posterior parietal cortex discriminated the perceptual intensities of stickiness, which was not present in the uni-variate analysis. Next, we applied a principal component analysis (PCA) to the voxel response patterns within identified clusters so as to find low-dimensional neural representations of stickiness intensities. Follow-up clustering analyses clearly showed separate neural grouping configurations between the Supra- and Infra-threshold groups. Interestingly, this neural categorization was in line with the perceptual grouping pattern obtained from the psychophysical data. Our findings thus suggest that different stickiness intensities would elicit distinct neural activity patterns in the human brain and may provide a neural basis for the perception and categorization of tactile stickiness. PMID:28936171

  5. Functional Brain Activation in Response to a Clinical Vestibular Test Correlates with Balance.

    Science.gov (United States)

    Noohi, Fatemeh; Kinnaird, Catherine; DeDios, Yiri; Kofman, Igor S; Wood, Scott; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

    2017-01-01

    The current study characterizes brain fMRI activation in response to two modes of vestibular stimulation: Skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either a vestibulo-spinal reflex [saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)], or an ocular muscle response [utricle-mediated ocular VEMP (oVEMP)]. Research suggests that the skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for subjects than the high decibel tones required to elicit VEMPs. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of brain activity. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that pneumatically powered skull taps would elicit a similar pattern of brain activity as shown in previous studies. Our results provide the first evidence of using pneumatically powered skull taps to elicit vestibular activity inside the MRI scanner. A conjunction analysis revealed that skull taps elicit overlapping activation with auditory tone bursts in the canonical vestibular cortical regions. Further, our postural control assessments revealed that greater amplitude of brain activation in response to vestibular stimulation was associated with better balance control for both techniques. Additionally, we found that skull taps elicit more robust vestibular activity compared to auditory tone bursts, with less reported aversive effects, highlighting the utility of this approach for future clinical and basic science research.

  6. Ongoing brain activity fluctuations directly account for intertrial and indirectly for intersubject variability in Stroop task performance.

    Science.gov (United States)

    Coste, Clio P; Sadaghiani, Sepideh; Friston, Karl J; Kleinschmidt, Andreas

    2011-11-01

    Recent studies have established a relation between ongoing brain activity fluctuations and intertrial variability in evoked neural responses, perception, and motor performance. Here, we extended these investigations into the domain of cognitive control. Using functional neuroimaging and a sparse event-related design (with long and unpredictable intervals), we measured ongoing activity fluctuations and evoked responses in volunteers performing a Stroop task with color-word interference. Across trials, prestimulus activity of several regions predicted subsequent response speed and across subjects this effect scaled with the Stroop effect size, being significant only in subjects manifesting behavioral interference. These effects occurred only in task relevant as the dorsal anterior cingulate and dorsolateral prefrontal cortex as well as ventral visual areas sensitive to color and visual words. Crucially, in subjects showing a Stroop effect, reaction times were faster when prestimulus activity was higher in task-relevant (color) regions and slower when activity was higher in irrelevant (word form) regions. These findings suggest that intrinsic brain activity fluctuations modulate neural mechanisms underpinning selective voluntary attention and cognitive control. Rephrased in terms of predictive coding models, ongoing activity can hence be considered a proxy of the precision (gain) with which prediction error signals are transmitted upon sensory stimulation.

  7. 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.

  8. Functional magnetic resonance imaging of higher brain activity

    International Nuclear Information System (INIS)

    Cui He; Wang Yunjiu; Chen Runsheng; Tang Xiaowei.

    1996-01-01

    Functional magnetic resonance images (fMRIs) exhibit small differences in the magnetic resonance signal intensity in positions corresponding to focal areas of brain activation. These signal are caused by variation in the oxygenation state of the venous vasculature. Using this non-invasive and dynamic method, it is possible to localize functional brain activation, in vivo, in normal individuals, with an accuracy of millimeters and a temporal resolution of seconds. Though a series of technical difficulties remain, fMRI is increasingly becoming a key method for visualizing the working brain, and uncovering the topographical organization of the human brain, and understanding the relationship between brain and the mind

  9. Calcium influx through hyperpolarization-activated cation channels (I(h) channels) contributes to activity-evoked neuronal secretion.

    Science.gov (United States)

    Yu, Xiao; Duan, Kai-Lai; Shang, Chun-Feng; Yu, Han-Gang; Zhou, Zhuan

    2004-01-27

    The hyperpolarization-activated cation channels (I(h)) play a distinct role in rhythmic activities in a variety of tissues, including neurons and cardiac cells. In the present study, we investigated whether Ca(2+) can permeate through the hyperpolarization-activated pacemaker channels (HCN) expressed in HEK293 cells and I(h) channels in dorsal root ganglion (DRG) neurons. Using combined measurements of whole-cell currents and fura-2 Ca(2+) imaging, we found that there is a Ca(2+) influx in proportion to I(h) induced by hyperpolarization in HEK293 cells. The I(h) channel blockers Cs(+) and ZD7288 inhibit both HCN current and Ca(2+) influx. Measurements of the fractional Ca(2+) current showed that it constitutes 0.60 +/- 0.02% of the net inward current through HCN4 at -120 mV. This fractional current is similar to that of the low Ca(2+)-permeable AMPA-R (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor) channels in Purkinje neurons. In DRG neurons, activation of I(h) for 30 s also resulted in a Ca(2+) influx and an elevated action potential-induced secretion, as assayed by the increase in membrane capacitance. These results suggest a functional significance for I(h) channels in modulating neuronal secretion by permitting Ca(2+) influx at negative membrane potentials.

  10. The differences of brain cortical activation between superficial pain and deep pain

    International Nuclear Information System (INIS)

    Ikemoto, Tatsunori; Ushida, Takahiro; Taniguchi, Shinichirou; Tani, Toshikazu; Morio, Kazuo; Sasaki, Toshikazu; Tanaka, Shigeki

    2006-01-01

    Using functional magnetic resonance imaging (FMRI) technology, we investigated the difference of pain related brain cortical activation derived from noxious stimulation to the skin and muscular tissue. Ten healthy volunteers who have no history of brain vascular disease were enrolled in this study. A cutaneous pain was provoked by isotonic (0.9%) saline injection into intra-dermal space on right lower leg through 24G plastic catheter, and a muscle pain was provoked by hypertonic (3%) saline injection into right tibialis anterior muscle. We used event-related FMRI to measure brain activity during each injection. Visual analogue scale (VAS) was used to quantify pain intensity and unpleasantness, and pain quality was assessed with several verbal descriptions. Pain unpleasantness rating was higher in the muscle pain compared to the cutaneous pain, despite the same pain intensity rating. The cutaneous pain had more acute pain onset than the muscle pain. Pain duration after stimulation was short in the cutaneous pain, but long in the muscle pain. The extent of the painful region tended to be larger with the muscle pain, but there was no statistical significance. Evoked FMRI response from the cutaneous pain showed distinct brain activation in the inferior and superior parietal cortex (BA: Brodmann area 5/7/40), primary and secondary somatosensory cortex (S1 and S2), insula, supplementary motor area (SMA, BA6), posterior cingulate cortex and cerebellum. On the other hand, FMRI response from muscle pain showed distinct brain activation mainly in the contralateral insula. These results suggest that the parietal lobe including the S1 is the essential area for cognition of sharp and well-localized pain conditions such as cutaneous pain, and may not be essential for cognition of diffuse pain derived from muscular tissue. (author)

  11. Activation of serotonin 2A receptors underlies the psilocybin-induced effects on α oscillations, N170 visual-evoked potentials, and visual hallucinations.

    Science.gov (United States)

    Kometer, Michael; Schmidt, André; Jäncke, Lutz; Vollenweider, Franz X

    2013-06-19

    Visual illusions and hallucinations are hallmarks of serotonergic hallucinogen-induced altered states of consciousness. Although the serotonergic hallucinogen psilocybin activates multiple serotonin (5-HT) receptors, recent evidence suggests that activation of 5-HT2A receptors may lead to the formation of visual hallucinations by increasing cortical excitability and altering visual-evoked cortical responses. To address this hypothesis, we assessed the effects of psilocybin (215 μg/kg vs placebo) on both α oscillations that regulate cortical excitability and early visual-evoked P1 and N170 potentials in healthy human subjects. To further disentangle the specific contributions of 5-HT2A receptors, subjects were additionally pretreated with the preferential 5-HT2A receptor antagonist ketanserin (50 mg vs placebo). We found that psilocybin strongly decreased prestimulus parieto-occipital α power values, thus precluding a subsequent stimulus-induced α power decrease. Furthermore, psilocybin strongly decreased N170 potentials associated with the appearance of visual perceptual alterations, including visual hallucinations. All of these effects were blocked by pretreatment with the 5-HT2A antagonist ketanserin, indicating that activation of 5-HT2A receptors by psilocybin profoundly modulates the neurophysiological and phenomenological indices of visual processing. Specifically, activation of 5-HT2A receptors may induce a processing mode in which stimulus-driven cortical excitation is overwhelmed by spontaneous neuronal excitation through the modulation of α oscillations. Furthermore, the observed reduction of N170 visual-evoked potentials may be a key mechanism underlying 5-HT2A receptor-mediated visual hallucinations. This change in N170 potentials may be important not only for psilocybin-induced states but also for understanding acute hallucinatory states seen in psychiatric disorders, such as schizophrenia and Parkinson's disease.

  12. Expression of gp120 in mice evokes anxiety behavior: co-occurrence with increased dendritic spines and brain-derived neurotrophic factor in the amygdala

    Science.gov (United States)

    Bachis, Alessia; Forcelli, Patrick; Masliah, Eliezer; Campbell, Lee; Mocchetti, Italo

    2016-01-01

    Human immunodeficiency virus type 1 (HIV) infection of the brain produces cognitive and motor disorders. In addition, HIV positive individuals exhibit behavioral alterations, such as apathy, and a decrease in spontaneity or emotional responses, typically seen in anxiety disorders. Anxiety can lead to psychological stress, which has been shown to influence HIV disease progression. These considerations underscore the importance of determining if anxiety in HIV is purely psychosocial, or if by contrast, there are the molecular cascades associated directly with HIV infection that may mediate anxiety. The present study had two goals: 1) to determine if chronic exposure to viral proteins would induce anxiety-like behavior in an animal model and 2) to determine if this exposure results in anatomical abnormalities that could explain increased anxiety. We have used gp120 transgenic mice, which display behavior and molecular deficiencies similar to HIV positive subjects with cognitive and motor impairments. In comparison to wild type mice, 6 months old gp120 transgenic mice demonstrated an anxiety like behavior measured by open field, light/dark transition task, and prepulse inhibition tests. Moreover, gp120 transgenic mice have an increased number of spines in the amygdala, as well as higher levels of brain-derived neurotrophic factor and tissue plasminogen activator when compared to age-matched wild type. Our data support the hypothesis that HIV, through gp120, may cause structural changes in the amygdala that lead to maladaptive responses to anxiety. PMID:26845379

  13. Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

    Science.gov (United States)

    Nishida, Kazuhiko; Matsumura, Shinji; Taniguchi, Wataru; Uta, Daisuke; Furue, Hidemasa; Ito, Seiji

    2014-01-01

    The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET)-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

  14. Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

    Directory of Open Access Journals (Sweden)

    Kazuhiko Nishida

    Full Text Available The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

  15. Scent-evoked nostalgia.

    Science.gov (United States)

    Reid, Chelsea A; Green, Jeffrey D; Wildschut, Tim; Sedikides, Constantine

    2015-01-01

    Can scents evoke nostalgia; what might be the psychological implications of such an evocation? Participants sampled 12 scents and rated the extent to which each scent was familiar, arousing and autobiographically relevant, as well as the extent to which each scent elicited nostalgia. Participants who were high (compared to low) in nostalgia proneness reported more scent-evoked nostalgia, and scents elicited greater nostalgia to the extent that they were arousing, familiar and autobiographically relevant. Scent-evoked nostalgia predicted higher levels of positive affect, self-esteem, self-continuity, optimism, social connectedness and meaning in life. In addition, scent-evoked nostalgia was characterised by more positive emotions than either non-nostalgic autobiographical memories or non-nostalgic non-autobiographical memories. Finally, scent-evoked nostalgia predicted in-the-moment feelings of personal (general or object-specific) nostalgia. The findings represent a foray into understanding the triggers and affective signature of scent-evoked nostalgia.

  16. Supervised learning for neural manifold using spatiotemporal brain activity.

    Science.gov (United States)

    Kuo, Po-Chih; Chen, Yong-Sheng; Chen, Li-Fen

    2015-12-01

    Determining the means by which perceived stimuli are compactly represented in the human brain is a difficult task. This study aimed to develop techniques for the construction of the neural manifold as a representation of visual stimuli. We propose a supervised locally linear embedding method to construct the embedded manifold from brain activity, taking into account similarities between corresponding stimuli. In our experiments, photographic portraits were used as visual stimuli and brain activity was calculated from magnetoencephalographic data using a source localization method. The results of 10 × 10-fold cross-validation revealed a strong correlation between manifolds of brain activity and the orientation of faces in the presented images, suggesting that high-level information related to image content can be revealed in the brain responses represented in the manifold. Our experiments demonstrate that the proposed method is applicable to investigation into the inherent patterns of brain activity.

  17. 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.

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

    DEFF Research Database (Denmark)

    Nielsen, Bodil; Hyldig, Tino; Bidstrup, F.

    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...... min of exercise; P

  19. 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.

  20. A comparison of auditory evoked potentials to acoustic beats and to binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2010-04-01

    The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source current density estimates of ERP components to beats-evoked oscillations were determined and compared across beat types, beat frequencies and base (carrier) frequencies. All stimuli evoked tone-onset components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude in response to acoustic than to binaural beats, to 250 than to 1000 Hz base frequency and to 3 Hz than to 6 Hz beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left temporal lobe areas. Differences between estimated sources of potentials to acoustic and binaural beats were not significant. The perceptions of binaural beats involve cortical activity that is not different than acoustic beats in distribution and in the effects of beat- and base frequency, indicating similar cortical processing. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Slow fluctuations in eye position and resting-state functional magnetic resonance imaging brain activity during visual fixation.

    Science.gov (United States)

    Fransson, Peter; Flodin, Pär; Seimyr, Gustaf Öqvist; Pansell, Tony

    2014-12-01

    The neuronal circuitry that supports voluntary changes in eye position in tasks that require attention-driven oculo-motor control is well known. However, less is known about the neuronal basis for eye control during visual fixation. This, together with the fact that visual fixation is one of the most commonly used baseline conditions in resting-state functional magnetic resonance imaging (fMRI) studies, prompted us to conduct a study in which we employed resting-state fMRI and concurrent recordings of eye gaze to investigate the relationship between spontaneous changes in eye position during passive visual fixation and intrinsic brain activity. As a control experiment, we recorded fMRI brain activity related to cued voluntary vertical and horizontal changes in eye position in a block-related task-evoked fMRI experiment. Our results for the voluntarily performed changes in eye position elicited brain activity in the bilateral occipitotemporal cortex, supplementary motor cortex and frontal eye fields. In contrast, we show that slow fluctuations in eye position during passive visual fixation are linked to intrinsic brain activity, foremost in midline cortical brain regions located in the posteromedial parietal cortex and the medial prefrontal cortex, brain regions that act as core cortical hubs in the brain's default mode network. Our results suggest that subconscious and sustained changes in behavior are tied to intrinsic brain activity on a moment-by-moment basis. © 2014 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  2. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...

  3. Identification of neonatal hearing impairment: evaluation of transient evoked otoacoustic emission, distortion product otoacoustic emission, and auditory brain stem response test performance.

    Science.gov (United States)

    Norton, S J; Gorga, M P; Widen, J E; Folsom, R C; Sininger, Y; Cone-Wesson, B; Vohr, B R; Mascher, K; Fletcher, K

    2000-10-01

    The purpose of this study was to compare the performance of transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), and auditory brain stem responses (ABRs) as tools for identification of neonatal hearing impairment. A total of 4911 infants including 4478 graduates of neonatal intensive care units, 353 well babies with one or more risk factors for hearing loss (Joint Committee on Infant Hearing, 1994) and 80 well babies without risk factor who did not pass one or more neonatal test were targeted as the potential subject pool on which test performance would be assessed. During the neonatal period, they were evaluated using TEOAEs in response to an 80 dB pSPL click, DPOAE responses to two stimulus conditions (L1 = L2 = 75 dB SPL and L1 = 65 dB SPL L2 = 50 dB SPL), and ABR elicited by a 30 dB nHL click. In an effort to describe test performance, these "at-risk" infants were asked to return for behavioral audiologic assessments, using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age, regardless of neonatal test results. Sixty-four percent of these subjects returned and reliable VRA data were obtained on 95.6% of these returnees. This approach is in contrast to previous studies in which, by necessity, efforts were made to follow only those infants who "failed" the neonatal screening tests. The accuracy of the neonatal measures in predicting hearing status at 8 to 12 mo corrected age was determined. Only those infants who provided reliable, monaural VRA test results were included in the analysis. Separate analyses were performed without regard to intercurrent events (i.e., events between the neonatal and VRA tests that could cause their results to disagree), and then after accounting for the possible influence of intercurrent events such as otitis media and late-onset or progressive hearing loss. Low refer rates were achieved for the stopping criteria used in the present study, especially when a protocol

  4. 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.

  5. Nicotinic receptor activation contrasts pathophysiological bursting and neurodegeneration evoked by glutamate uptake block on rat hypoglossal motoneurons.

    Science.gov (United States)

    Corsini, Silvia; Tortora, Maria; Nistri, Andrea

    2016-11-15

    Impaired uptake of glutamate builds up the extracellular level of this excitatory transmitter to trigger rhythmic neuronal bursting and delayed cell death in the brainstem motor nucleus hypoglossus. This process is the expression of the excitotoxicity that underlies motoneuron degeneration in diseases such as amyotrophic lateral sclerosis affecting bulbar motoneurons. In a model of motoneuron excitotoxicity produced by pharmacological block of glutamate uptake in vitro, rhythmic bursting is suppressed by activation of neuronal nicotinic receptors with their conventional agonist nicotine. Emergence of bursting is facilitated by nicotinic receptor antagonists. Following excitotoxicity, nicotinic receptor activity decreases mitochondrial energy dysfunction, endoplasmic reticulum stress and production of toxic radicals. Globally, these phenomena synergize to provide motoneuron protection. Nicotinic receptors may represent a novel target to contrast pathological overactivity of brainstem motoneurons and therefore to prevent their metabolic distress and death. Excitotoxicity is thought to be one of the early processes in the onset of amyotrophic lateral sclerosis (ALS) because high levels of glutamate have been detected in the cerebrospinal fluid of such patients due to dysfunctional uptake of this transmitter that gradually damages brainstem and spinal motoneurons. To explore potential mechanisms to arrest ALS onset, we used an established in vitro model of rat brainstem slice preparation in which excitotoxicity is induced by the glutamate uptake blocker dl-threo-β-benzyloxyaspartate (TBOA). Because certain brain neurons may be neuroprotected via activation of nicotinic acetylcholine receptors (nAChRs) by nicotine, we investigated if nicotine could arrest excitotoxic damage to highly ALS-vulnerable hypoglossal motoneurons (HMs). On 50% of patch-clamped HMs, TBOA induced intense network bursts that were inhibited by 1-10 μm nicotine, whereas nAChR antagonists

  6. Nicotinic receptor activation contrasts pathophysiological bursting and neurodegeneration evoked by glutamate uptake block on rat hypoglossal motoneurons

    Science.gov (United States)

    Corsini, Silvia; Tortora, Maria

    2016-01-01

    Key points Impaired uptake of glutamate builds up the extracellular level of this excitatory transmitter to trigger rhythmic neuronal bursting and delayed cell death in the brainstem motor nucleus hypoglossus.This process is the expression of the excitotoxicity that underlies motoneuron degeneration in diseases such as amyotrophic lateral sclerosis affecting bulbar motoneurons.In a model of motoneuron excitotoxicity produced by pharmacological block of glutamate uptake in vitro, rhythmic bursting is suppressed by activation of neuronal nicotinic receptors with their conventional agonist nicotine. Emergence of bursting is facilitated by nicotinic receptor antagonists.Following excitotoxicity, nicotinic receptor activity decreases mitochondrial energy dysfunction, endoplasmic reticulum stress and production of toxic radicals. Globally, these phenomena synergize to provide motoneuron protection.Nicotinic receptors may represent a novel target to contrast pathological overactivity of brainstem motoneurons and therefore to prevent their metabolic distress and death. Abstract Excitotoxicity is thought to be one of the early processes in the onset of amyotrophic lateral sclerosis (ALS) because high levels of glutamate have been detected in the cerebrospinal fluid of such patients due to dysfunctional uptake of this transmitter that gradually damages brainstem and spinal motoneurons. To explore potential mechanisms to arrest ALS onset, we used an established in vitro model of rat brainstem slice preparation in which excitotoxicity is induced by the glutamate uptake blocker dl‐threo‐β‐benzyloxyaspartate (TBOA). Because certain brain neurons may be neuroprotected via activation of nicotinic acetylcholine receptors (nAChRs) by nicotine, we investigated if nicotine could arrest excitotoxic damage to highly ALS‐vulnerable hypoglossal motoneurons (HMs). On 50% of patch‐clamped HMs, TBOA induced intense network bursts that were inhibited by 1–10 μm nicotine

  7. Commonality of neural representations of sentences across languages: Predicting brain activation during Portuguese sentence comprehension using an English-based model of brain function.

    Science.gov (United States)

    Yang, Ying; Wang, Jing; Bailer, Cyntia; Cherkassky, Vladimir; Just, Marcel Adam

    2017-02-01

    The aim of the study was to test the cross-language generative capability of a model that predicts neural activation patterns evoked by sentence reading, based on a semantic characterization of the sentence. In a previous study on English monolingual speakers (Wang et al., submitted), a computational model performed a mapping from a set of 42 concept-level semantic features (Neurally Plausible Semantic Features, NPSFs) as well as 6 thematic role markers to neural activation patterns (assessed with fMRI), to predict activation levels in a network of brain locations. The model used two types of information gained from the English-based fMRI data to predict the activation for individual sentences in Portuguese. First, it used the mapping weights from NPSFs to voxel activation levels derived from the model for English reading. Second, the brain locations for which the activation levels were predicted were derived from a factor analysis of the brain activation patterns during English reading. These meta-language locations were defined by the clusters of voxels with high loadings on each of the four main dimensions (factors), namely people, places, actions and feelings, underlying the neural representations of the stimulus sentences. This cross-language model succeeded in predicting the brain activation patterns associated with the reading of 60 individual Portuguese sentences that were entirely new to the model, attaining accuracies reliably above chance level. The prediction accuracy was not affected by whether the Portuguese speaker was monolingual or Portuguese-English bilingual. The model's confusion errors indicated an accurate capture of the events or states described in the sentence at a conceptual level. Overall, the cross-language predictive capability of the model demonstrates the neural commonality between speakers of different languages in the representations of everyday events and states, and provides an initial characterization of the common meta

  8. Monitoring User’s Brain Activity for a Virtual Coach

    NARCIS (Netherlands)

    van de Laar, B.L.A.; Nijholt, Antinus; Zwiers, Jakob; Yang, Hyung Seung; Malaka, Rainer; Hoshino, Junichi; Han, Jung Hyun

    2010-01-01

    The system described in this paper is an attempt at developing a coach for sports using a virtual world and multimodal interaction, including brain activity. Users can ride a bicycle through a virtual world while the coach monitors the user’s performance. The system incorporates the user’s brain

  9. Modulating spontaneous brain activity using repetitive transcranial magnetic stimulation

    NARCIS (Netherlands)

    van der Werf, Y.D.; Sanz-Arigita, E.J.; Menning, S.; van den Heuvel, O.A.

    2010-01-01

    Background: When no specific stimulus or task is presented, spontaneous fluctuations in brain activity occur. Brain regions showing such coherent fluctuations are thought to form organized networks known as 'resting-state' networks, a main representation of which is the default mode network.

  10. Lost for emotion words: What motor and limbic brain activity reveals about autism and semantic theory

    Science.gov (United States)

    Moseley, Rachel L.; Shtyrov, Yury; Mohr, Bettina; Lombardo, Michael V.; Baron-Cohen, Simon; Pulvermüller, Friedemann

    2015-01-01

    Autism spectrum conditions (ASC) are characterised by deficits in understanding and expressing emotions and are frequently accompanied by alexithymia, a difficulty in understanding and expressing emotion words. Words are differentially represented in the brain according to their semantic category and these difficulties in ASC predict reduced activation to emotion-related words in limbic structures crucial for affective processing. Semantic theories view ‘emotion actions’ as critical for learning the semantic relationship between a word and the emotion it describes, such that emotion words typically activate the cortical motor systems involved in expressing emotion actions such as facial expressions. As ASC are also characterised by motor deficits and atypical brain structure and function in these regions, motor structures would also be expected to show reduced activation during emotion-semantic processing. Here we used event-related fMRI to compare passive processing of emotion words in comparison to abstract verbs and animal names in typically-developing controls and individuals with ASC. Relatively reduced brain activation in ASC for emotion words, but not matched control words, was found in motor areas and cingulate cortex specifically. The degree of activation evoked by emotion words in the motor system was also associated with the extent of autistic traits as revealed by the Autism Spectrum Quotient. We suggest that hypoactivation of motor and limbic regions for emotion word processing may underlie difficulties in processing emotional language in ASC. The role that sensorimotor systems and their connections might play in the affective and social-communication difficulties in ASC is discussed. PMID:25278250

  11. Spatial heterogeneity analysis of brain activation in fMRI

    Directory of Open Access Journals (Sweden)

    Lalit Gupta

    2014-01-01

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

  12. Disentangling brain activity related to the processing of emotional visual information and emotional arousal.

    Science.gov (United States)

    Kuniecki, Michał; Wołoszyn, Kinga; Domagalik, Aleksandra; Pilarczyk, Joanna

    2018-05-01

    Processing of emotional visual information engages cognitive functions and induces arousal. We aimed to examine the modulatory role of emotional valence on brain activations linked to the processing of visual information and those linked to arousal. Participants were scanned and their pupil size was measured while viewing negative and neutral images. The visual noise was added to the images in various proportions to parametrically manipulate the amount of visual information. Pupil size was used as an index of physiological arousal. We show that arousal induced by the negative images, as compared to the neutral ones, is primarily related to greater amygdala activity while increasing visibility of negative content to enhanced activity in the lateral occipital complex (LOC). We argue that more intense visual processing of negative scenes can occur irrespective of the level of arousal. It may suggest that higher areas of the visual stream are fine-tuned to process emotionally relevant objects. Both arousal and processing of emotional visual information modulated activity within the ventromedial prefrontal cortex (vmPFC). Overlapping activations within the vmPFC may reflect the integration of these aspects of emotional processing. Additionally, we show that emotionally-evoked pupil dilations are related to activations in the amygdala, vmPFC, and LOC.

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

    National Research Council Canada - National Science Library

    West, Bruce

    1988-01-01

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

  14. Brain activation during human male ejaculation

    NARCIS (Netherlands)

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

    2003-01-01

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

  15. Neural responses to nostalgia-evoking music modeled by elements of dynamic musical structure and individual differences in affective traits.

    Science.gov (United States)

    Barrett, Frederick S; Janata, Petr

    2016-10-01

    Nostalgia is an emotion that is most commonly associated with personally and socially relevant memories. It is primarily positive in valence and is readily evoked by music. It is also an idiosyncratic experience that varies between individuals based on affective traits. We identified frontal, limbic, paralimbic, and midbrain brain regions in which the strength of the relationship between ratings of nostalgia evoked by music and blood-oxygen-level-dependent (BOLD) signal was predicted by affective personality measures (nostalgia proneness and the sadness scale of the Affective Neuroscience Personality Scales) that are known to modulate the strength of nostalgic experiences. We also identified brain areas including the inferior frontal gyrus, substantia nigra, cerebellum, and insula in which time-varying BOLD activity correlated more strongly with the time-varying tonal structure of nostalgia-evoking music than with music that evoked no or little nostalgia. These findings illustrate one way in which the reward and emotion regulation networks of the brain are recruited during the experiencing of complex emotional experiences triggered by music. These findings also highlight the importance of considering individual differences when examining the neural responses to strong and idiosyncratic emotional experiences. Finally, these findings provide a further demonstration of the use of time-varying stimulus-specific information in the investigation of music-evoked experiences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Regional brain activity in women grieving a romantic relationship breakup.

    Science.gov (United States)

    Najib, Arif; Lorberbaum, Jeffrey P; Kose, Samet; Bohning, Daryl E; George, Mark S

    2004-12-01

    Separation from loved ones commonly leads to grief reactions. In some individuals, grief can evolve into a major depressive episode. The brain regions involved in grief have not been specifically studied. The authors studied brain activity in women actively grieving a recent romantic relationship breakup. It was hypothesized that while remembering their ex-partner, subjects would have altered brain activity in regions identified in sadness imaging studies: the cerebellum, anterior temporal cortex, insula, anterior cingulate, and prefrontal cortex. Nine right-handed women whose romantic relationship ended within the preceding 4 months were studied. Subjects were scanned using blood-oxygen-level-dependent functional magnetic resonance imaging while they alternated between recalling a sad, ruminative thought about their loved one (grief state) and a neutral thought about a different person they knew an equally long time. Acute grief (grief minus neutral state) was associated with increased group activity in posterior brain regions, including the cerebellum, posterior brainstem, and posterior temporoparietal and occipital brain regions. Decreased activity was more prominent anteriorly and on the left and included the anterior brainstem, thalamus, striatum, temporal cortex, insula, and dorsal and ventral anterior cingulate/prefrontal cortex. When a more lenient statistical threshold for regions of interest was used, additional increases were found in the lateral temporal cortex, supragenual anterior cingulate/medial prefrontal cortex, and right inferomedial dorsolateral prefrontal cortex, all of which were adjacent to spatially more prominent decreases. In nearly all brain regions showing brain activity decreases with acute grief, activity decreases were greater in women reporting higher grief levels over the past 2 weeks. During acute grief, subjects showed brain activity changes in the cerebellum, anterior temporal cortex, insula, anterior cingulate, and prefrontal

  17. The neurobiology of brain and cognitive reserve: mental and physical activity as modulators of brain disorders.

    Science.gov (United States)

    Nithianantharajah, Jess; Hannan, Anthony J

    2009-12-01

    The concept of 'cognitive reserve', and a broader theory of 'brain reserve', were originally proposed to help explain epidemiological data indicating that individuals who engaged in higher levels of mental and physical activity via education, occupation and recreation, were at lower risk of developing Alzheimer's disease and other forms of dementia. Subsequently, behavioral, cellular and molecular studies in animals (predominantly mice and rats) have revealed dramatic effects of environmental enrichment, which involves enhanced levels of sensory, cognitive and motor stimulation via housing in novel, complex environments. Furthermore, increasing levels of voluntary physical exercise, via ad libitum access to running wheels, can have significant effects on brain and behavior, thus informing the relative effects of mental and physical activity. More recently, animal models of brain disorders have been compared under environmentally stimulating and standard housing conditions, and this has provided new insights into environmental modulators and gene-environment interactions involved in pathogenesis. Here, we review animal studies that have investigated the effects of modifying mental and physical activity via experimental manipulations, and discuss their relevance to brain and cognitive reserve (BCR). Recent evidence suggests that the concept of BCR is not only relevant to brain aging, neurodegenerative diseases and dementia, but also to other neurological and psychiatric disorders. Understanding the cellular and molecular mechanisms mediating BCR may not only facilitate future strategies aimed at optimising healthy brain aging, but could also identify molecular targets for novel pharmacological approaches aimed at boosting BCR in 'at risk' and symptomatic individuals with various brain disorders.

  18. Functional connectivity and brain activation: a synergistic approach.

    Science.gov (United States)

    Tomasi, Dardo; Wang, Ruiliang; Wang, Gene-Jack; Volkow, Nora D

    2014-10-01

    Traditional functional magnetic resonance imaging (fMRI) studies exploit endogenous brain activity for mapping brain activation during "periodic" cognitive/emotional challenges or brain functional connectivity during the "resting state". Previous studies demonstrated that these approaches provide a limited view of brain function which can be complemented by each other. We hypothesized that graph theory functional connectivity density (FCD) mapping would demonstrate regional FCD decreases between resting-state scan and a continuous "task-state" scan. Forty-five healthy volunteers underwent functional connectivity MRI during resting-state as well as a continuous visual attention task, and standard fMRI with a blocked version of the visual attention task. High-resolution data-driven FCD mapping was used to measure task-related connectivity changes without a priori hypotheses. Results demonstrate that task performance was associated with FCD decreases in brain regions weakly activated/deactivated by the task. Furthermore, a pronounced negative correlation between blood oxygen level-dependent-fMRI activation and task-related FCD decreases emerged across brain regions that also suggest the disconnection of task-irrelevant networks during task performance. The correlation between improved accuracy and stronger FCD decreases further suggests the disconnection of task-irrelevant networks during task performance. Functional connectivity can potentiate traditional fMRI studies and offer a more complete picture of brain function. Published by Oxford University Press 2013. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  19. Extension of non-invasive EEG into the kHz range for evoked thalamocortical activity by means of very low noise amplifiers.

    Science.gov (United States)

    Scheer, H J; Fedele, T; Curio, G; Burghoff, M

    2011-12-01

    Ultrafast electroencephalographic signals, having frequencies above 500 Hz, can be observed in somatosensory evoked potential measurements. Usually, these recordings have a poor signal-to-noise ratio (SNR) because weak signals are overlaid by intrinsic noise of much higher amplitude like that generated by biological sources and the amplifier. As an example, recordings at the scalp taken during electrical stimulation of the median nerve show a 600 Hz burst with submicro-volt amplitudes which can be extracted from noise by the use of massive averaging and digital signal processing only. We have investigated this signal by means of a very low noise amplifier made in-house (minimal voltage noise 2.7 nV Hz(-1/2), FET inputs). We examined how the SNR of the data is altered by the bandwidth and the use of amplifiers with different intrinsic amplifier noise levels of 12 and 4.8 nV Hz(-1/2), respectively. By analyzing different frequency contributions of the signal, we found an extremely weak 1 kHz component superimposed onto the well-known 600 Hz burst. Previously such high-frequency electroencephalogram responses around 1 kHz have only been observed by deep brain electrodes implanted for tremor therapy of Parkinson patients. For the non-invasive measurement of such signals, we recommend that amplifier noise should not exceed 4 nV Hz(-1/2).

  20. Topographic Brain Mapping: A Window on Brain Function?

    Science.gov (United States)

    Karniski, Walt M.

    1989-01-01

    The article reviews the method of topographic mapping of the brain's electrical activity. Multiple electroencephalogram (EEG) electrodes and computerized analysis of the EEG signal are used to generate maps of frequency and voltage (evoked potential). This relatively new technique holds promise in the evaluation of children with behavioral and…

  1. Light touch induces ERK activation in superficial dorsal horn neurons after inflammation: involvement of spinal astrocytes and JNK signaling in touch-evoked central sensitization and mechanical allodynia

    Science.gov (United States)

    Gao, Yong-Jing; Ji, Ru-Rong

    2010-01-01

    Activation of extracellular signal-regulated kinase (ERK) in spinal cord neurons could serve as a marker for sensitization of dorsal horn neurons in persistent pain. ERK is normally activated by high-threshold noxious stimuli. We investigated how low-threshold mechanical stimuli could activate ERK after complete Freund’s adjuvant (CFA)-induced inflammation. Unilateral injection of CFA induced ipsilateral heat hyperalgesia and bilateral mechanical allodynia. CFA-induced ERK activation in ipsilateral dorsal horn neurons declined after 2 days. Interestingly, low threshold mechanical stimulation given by light touch either on the inflamed paw or the contralateral non-inflamed paw dramatically increased ERK phosphorylation (pERK) in the dorsal horn ipsilateral to touch stimulation. Notably, light touch induced pERK mainly in superficial neurons in laminae I-IIo. Intrathecal administration of the astroglial toxin L-α-aminoadipate (L-α-AA) on post-CFA day 2 reversed CFA-induced bilateral mechanical allodynia but not heat hyperalgesia. Furthermore, L-α-AA, the glial inhibitor fluorocitrate, and a peptide inhibitor of c-Jun N-terminal Kinase (JNK) all reduced light touch-evoked ERK activation ipsilateral to touch. Collectively, these data suggest that (a) ERK can be activated in superficial dorsal horn neurons by low threshold mechanical stimulation under pathological condition and (b) ERK activation by light touch is associated with mechanical allodynia and requires an astrocyte network. PMID:20722971

  2. 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.

  3. Evoked electrical and cerebral vascular responses during sleep and following sleep deprivation.

    Science.gov (United States)

    Schei, Jennifer L; Rector, David M

    2011-01-01

    Neuronal activity elicits vascular dilation, delivering additional blood and metabolites to the activated region. With increasing neural activity, vessels stretch and may become less compliant. Most functional imaging studies assume that limits to vascular expansion are not normally reached except under pathological conditions, with the possibility that metabolism could outpace supply. However, we previously demonstrated that evoked hemodynamic responses were larger during quiet sleep when compared to both waking and rapid eye movement (REM) sleep, suggesting that high basal activity during wake may elicit blunted evoked hemodynamic responses due to vascular expansion limits. We hypothesized that extended brain activity through sleep deprivation will further dilate blood vessels and exacerbate the blunted evoked hemodynamic responses observed during wake, and dampen responses in subsequent sleep. We measured evoked electrical and hemodynamic responses from rats using auditory clicks (0.5s, 10 Hz, 2-13s random ISIs) for 1h following 2, 4, or 6h of sleep deprivation. Time-of-day matched controls were recorded continuously for 7h. Within quiet sleep periods following deprivation, evoked response potential (ERP) amplitude did not differ; however, the evoked vascular response was smaller with longer sleep deprivation periods. These results suggest that prolonged neural activity periods 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 sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    Directory of Open Access Journals (Sweden)

    Roberto Vincis

    2015-07-01

    Full Text Available Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independent of neurotransmitter release and neurovascular coupling. Furthermore, our results suggest that odor-evoked parenchymal IOSs originate from changes in light scattering of olfactory sensory neuron axons, mostly due to water movement following action potential propagation. Our study sheds light on a direct correlate of neuronal activity, which may be used for large-scale functional brain imaging.

  5. 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.

  6. From abstract topology to real thermodynamic brain activity.

    Science.gov (United States)

    Tozzi, Arturo; Peters, James F

    2017-06-01

    Recent approaches to brain phase spaces reinforce the foremost role of symmetries and energy requirements in the assessment of nervous activity. Changes in thermodynamic parameters and dimensions occur in the brain during symmetry breakings and transitions from one functional state to another. Based on topological results and string-like trajectories into nervous energy landscapes, we provide a novel method for the evaluation of energetic features and constraints in different brain functional activities. We show how abstract approaches, namely the Borsuk-Ulam theorem and its variants, may display real, energetic physical counterparts. When topology meets the physics of the brain, we arrive at a general model of neuronal activity, in terms of multidimensional manifolds and computational geometry, that has the potential to be operationalized.

  7. A contribution to the study of spontaneous and evoked electrical activities of the adult rabbit hypothalamus and application of digital analysis

    International Nuclear Information System (INIS)

    Lasmoles, Francoise

    1974-01-01

    The spontaneous and evoked electrical activities of the hypothalamus were studied in 18 adult rabbits chronically implanted with electrodes. The graphic study of the EEG was completed by digital analyses of the signal considered as a random process and processed both by statistical analysis in order to know the distribution function of the signal amplitude and harmonic analysis allowing classification of power density spectra by the calculation of the autocorrelation function and its Fourier transform. Absolute values and percentage of energy distribution were obtained from 0 to 40 Hz for each frequency rate (0.25 Hz) and in various frequency bands (0-3, 3-6, 7-9, 9-15, 15-20, 20-30 and 30-40 Hz). The experimental methods (electrode implantation, data acquisition and processing) are described: 240 sequences corresponding to stable physiological states were analyzed after analogical-digital conversion (sampling rate: 10 ms, period of integration: 20 s). Whatever the state of vigilance, the hypothalamus had a fairly homogeneous function different from the spontaneous electrical activity of the cortex. The signal characteristics both in amplitude and frequency allowed to distinguish the hypothalamic areas studied (supra-optic area, mammillary body, postero-lateral hypothalamus). The results were reproducible and verified the information supplied by visual examination of the EEG. Following light stimulus, the evoked potentials were collected in the hypothalamus; there should therefore be convergence, yet since the answers are unstable and long latent, the neuronal paths followed by the impulse must not be direct. (author) [fr

  8. Voluntary breath holding affects spontaneous brain activity measured by magnetoencephalography

    NARCIS (Netherlands)

    Schellart, N. A.; Reits, D.

    1999-01-01

    Spontaneous brain activity was measured by multichannel magnetoencephalography (MEG) during voluntary breath holds. Significant changes in the activity are limited to the alpha rhythm: 0.25 Hz frequency increase and narrowing of the peak. The area of alpha activity shifts slightly toward (fronto-)

  9. To what extent can dry and water-based EEG electrodes replace conductive gel ones?: A Steady State Visual Evoked Potential Brain-Computer Interface Case Study

    NARCIS (Netherlands)

    Mihajlovic, V.; Garcia Molina, G.; Peuscher, J

    2011-01-01

    Recent technological advances in the field of skin electrodes and on-body sensors indicate a possibility of having an alternative to the traditionally used conductive gel electrodes for measuring electrical signals of the brain (electroencephalogram, EEG). This paper evaluates whether water-based

  10. Decoding the dynamic representation of musical pitch from human brain activity.

    Science.gov (United States)

    Sankaran, N; Thompson, W F; Carlile, S; Carlson, T A

    2018-01-16

    In music, the perception of pitch is governed largely by its tonal function given the preceding harmonic structure of the music. While behavioral research has advanced our understanding of the perceptual representation of musical pitch, relatively little is known about its representational structure in the brain. Using Magnetoencephalography (MEG), we recorded evoked neural responses to different tones presented within a tonal context. Multivariate Pattern Analysis (MVPA) was applied to "decode" the stimulus that listeners heard based on the underlying neural activity. We then characterized the structure of the brain's representation using decoding accuracy as a proxy for representational distance, and compared this structure to several well established perceptual and acoustic models. The observed neural representation was best accounted for by a model based on the Standard Tonal Hierarchy, whereby differences in the neural encoding of musical pitches correspond to their differences in perceived stability. By confirming that perceptual differences honor those in the underlying neuronal population coding, our results provide a crucial link in understanding the cognitive foundations of musical pitch across psychological and neural domains.

  11. Passive Double-Sensory Evoked Coherence Correlates with Long-Term Memory Capacity

    OpenAIRE

    Horwitz, Anna; Mortensen, Erik L.; Osler, Merete; Fagerlund, Birgitte; Lauritzen, Martin; Benedek, Krisztina

    2017-01-01

    HIGHLIGHTS Memory correlates with the difference between single and double-sensory evoked steady-state coherence in the gamma range (ΔC). The correlation is most pronounced for the anterior brain region (ΔC A ). The correlation is not driven by birth size, education, speed of processing, or intelligence. The sensitivity of ΔC A for detecting low memory capacity is 90%. Cerebral rhythmic activity and oscillations are important pathways of communication between cortical cell assemblies and may ...

  12. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    OpenAIRE

    Vincis; Lagier; van de Ville; Rodriguez; Carleton

    2015-01-01

    Summary Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS) imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely ...

  13. Brain activity of women is more fractal than men.

    Science.gov (United States)

    Ahmadi, Khodabakhsh; Ahmadlou, Mehran; Rezazade, Majid; Azad-Marzabadi, Esfandiar; Sajedi, Firoozeh

    2013-02-22

    Investigating gender differences of the brain is of both scientific and clinical importance, as understanding such differences may be helpful for improving gender specific treatments of neuropsychiatric disorders. As brain is a highly complex system, it is crucial to investigate its activity in terms of nonlinear dynamics. However, there are few studies that investigated gender differences based on dynamical characteristics of the brain. Fractal dimension (FD) is a key characteristic of the brain dynamics which indicates the level of complexity on which the neuronal regions function or interact and quantifies the associated brain processes on a scale ranging from fully deterministic to fully random. This study investigates the gender differences of brain dynamics, comparing fractal dimension of scalp EEGs (in eyes-closed resting state) of 34 female and 34 male healthy adults. The results showed significantly greater FDs in females compared to males in all brain regions except in lateral and occipital lobes. This indicates a higher complexity of the brain dynamics in females relative to males. The high accuracies of 87.8% and 93.1% obtained by logistic regression and enhanced probabilistic neural network, respectively, in discriminating between the gender groups based on the FDs also confirmed the great gender differences of complexity of brain activities. The results showed that delta, alpha, and beta bands are the frequency bands that contribute most to the gender differences in brain complexity. Furthermore, the lateralization analysis showed the leftward lateralization of complexity in females is greater than in males. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Patterns of brain and cardiovascular activation while solving rule-discovery and rule-application numeric tasks.

    Science.gov (United States)

    Sosnowski, Tytus; Rynkiewicz, Andrzej; Wordecha, Małgorzata; Kępkowicz, Anna; Majewska, Adrianna; Pstrągowska, Aleksandra; Oleksy, Tomasz; Wypych, Marek; Marchewka, Artur

    2017-07-01

    It is known that solving mental tasks leads to tonic increase in cardiovascular activity. Our previous research showed that tasks involving rule application (RA) caused greater tonic increase in cardiovascular activity than tasks requiring rule discovery (RD). However, it is not clear what brain mechanisms are responsible for this difference. The aim of two experimental studies was to compare the patterns of brain and cardiovascular activity while both RD and the RA numeric tasks were being solved. The fMRI study revealed greater brain activation while solving RD tasks than while solving RA tasks. In particular, RD tasks evoked greater activation of the left inferior frontal gyrus and selected areas in the parietal, and temporal cortices, including the precuneus, supramarginal gyrus, angular gyrus, inferior parietal lobule, and the superior temporal gyrus, and the cingulate cortex. In addition, RA tasks caused larger increases in HR than RD tasks. The second study, carried out in a cardiovascular laboratory, showed greater increases in heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) while solving RA tasks than while solving RD tasks. The results support the hypothesis that RD and RA tasks involve different modes of information processing, but the neuronal mechanism responsible for the observed greater cardiovascular response to RA tasks than to RD tasks is not completely clear. Copyright © 2017. Published by Elsevier B.V.

  15. Adverse Weather Evokes Nostalgia.

    Science.gov (United States)

    van Tilburg, Wijnand A P; Sedikides, Constantine; Wildschut, Tim

    2018-03-01

    Four studies examined the link between adverse weather and the palliative role of nostalgia. We proposed and tested that (a) adverse weather evokes nostalgia (Hypothesis 1); (b) adverse weather causes distress, which predicts elevated nostalgia (Hypothesis 2); (c) preventing nostalgia exacerbates weather-induced distress (Hypothesis 3); and (d) weather-evoked nostalgia confers psychological benefits (Hypothesis 4). In Study 1, participants listened to recordings of wind, thunder, rain, and neutral sounds. Adverse weather evoked nostalgia. In Study 2, participants kept a 10-day diary recording weather conditions, distress, and nostalgia. We also obtained meteorological data. Adverse weather perceptions were positively correlated with distress, which predicted higher nostalgia. Also, adverse natural weather was associated with corresponding weather perceptions, which predicted elevated nostalgia. (Results were mixed for rain.) In Study 3, preventing nostalgia (via cognitive load) increased weather-evoked distress. In Study 4, weather-evoked nostalgia was positively associated with psychological benefits. The findings pioneer the relevance of nostalgia as source of comfort in adverse weather.

  16. The role of calcium, calcium-activated K+ channels, and tyrosine/kinase in psoralen-evoked responses in human melanoma cells

    Directory of Open Access Journals (Sweden)

    Isoldi M.C.

    2004-01-01

    Full Text Available 8-Methoxy psoralen (8-MOP exerts a short-term (24 h mitogenic action, and a long-term (48-72 h anti-proliferative and melanogenic action on two human melanoma cell lines, SK-Mel 28 and C32TG. An increase of intracellular calcium concentration was observed by spectrofluorometry immediately after the addition of 0.1 mM 8-MOP to both cell lines, previously incubated with calcium probe fluo-3 AM (5 µM. The intracellular Ca2+ chelator BAPTA/AM (1 µM blocked both early (mitogenic and late (anti-proliferative and melanogenic 8-MOP effects on both cell lines, thus revealing the importance of the calcium signal in both short- and long-term 8-MOP-evoked responses. Long-term biological assays with 5 and 10 mM tetraethylammonium chloride (TEA, an inhibitor of Ca2+-dependent K+ channels did not affect the responses to psoralen; however, in 24-h assays 10 mM TEA blocked the proliferative peak, indicating a modulation of Ca2+-dependent K+ channels by 8-MOP. No alteration of cAMP basal levels or forskolin-stimulated cAMP levels was promoted by 8-MOP in SK-Mel 28 cells, as determined by radioimmunoassay. However, in C32TG cells forskolin-stimulated cAMP levels were further increased in the presence of 8-MOP. In addition, assays with 1 µM protein kinase C and calcium/calmodulin-dependent kinase inhibitors, Ro 31-8220 and KN-93, respectively, excluded the participation of these kinases in the responses evoked by 8-MOP. Western blot with antibodies anti-phosphotyrosine indicated a 92% increase of the phosphorylated state of a 43-kDa band, suggesting that the phosphorylation of this protein is a component of the cascade that leads to the increase of tyrosinase activity.

  17. Human brain activity with functional NIR optical imager

    Science.gov (United States)

    Luo, Qingming

    2001-08-01

    In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

  18. Maternal insulin sensitivity is associated with oral glucose-induced changes in fetal brain activity.

    Science.gov (United States)

    Linder, Katarzyna; Schleger, Franziska; Ketterer, Caroline; Fritsche, Louise; Kiefer-Schmidt, Isabelle; Hennige, Anita; Häring, Hans-Ulrich; Preissl, Hubert; Fritsche, Andreas

    2014-06-01

    Fetal programming plays an important role in the pathogenesis of type 2 diabetes. The aim of the present study was to investigate whether maternal metabolic changes during OGTT influence fetal brain activity. Thirteen healthy pregnant women underwent an OGTT (75 g). Insulin sensitivity was determined by glucose and insulin measurements at 0, 60 and 120 min. At each time point, fetal auditory evoked fields were recorded with a fetal magnetoencephalographic device and response latencies were determined. Maternal insulin increased from a fasting level of 67 ± 25 pmol/l (mean ± SD) to 918 ± 492 pmol/l 60 min after glucose ingestion and glucose levels increased from 4.4 ± 0.3 to 7.4 ± 1.1 mmol/l. Over the same time period, fetal response latencies decreased from 297 ± 99 to 235 ± 84 ms (p = 0.01) and then remained stable until 120 min (235 ± 84 vs 251 ± 91 ms, p = 0.39). There was a negative correlation between maternal insulin sensitivity and fetal response latencies 60 min after glucose ingestion (r = 0.68, p = 0.02). After a median split of the group based on maternal insulin sensitivity, fetuses of insulin-resistant mothers showed a slower response to auditory stimuli (283 ± 79 ms) than those of insulin-sensitive mothers (178 ± 46 ms, p = 0.03). Lower maternal insulin sensitivity is associated with slower fetal brain responses. These findings provide the first evidence of a direct effect of maternal metabolism on fetal brain activity and suggest that central insulin resistance may be programmed during fetal development.

  19. Visual short term memory related brain activity predicts mathematical abilities.

    Science.gov (United States)

    Boulet-Craig, Aubrée; Robaey, Philippe; Lacourse, Karine; Jerbi, Karim; Oswald, Victor; Krajinovic, Maja; Laverdière, Caroline; Sinnett, Daniel; Jolicoeur, Pierre; Lippé, Sarah

    2017-07-01

    Previous research suggests visual short-term memory (VSTM) capacity and mathematical abilities are significantly related. Moreover, both processes activate similar brain regions within the parietal cortex, in particular, the intraparietal sulcus; however, it is still unclear whether the neuronal underpinnings of VSTM directly correlate with mathematical operation and reasoning abilities. The main objective was to investigate the association between parieto-occipital brain activity during the retention period of a VSTM task and performance in mathematics. The authors measured mathematical abilities and VSTM capacity as well as brain activity during memory maintenance using magnetoencephalography (MEG) in 19 healthy adult participants. Event-related magnetic fields (ERFs) were computed on the MEG data. Linear regressions were used to estimate the strength of the relation between VSTM related brain activity and mathematical abilities. The amplitude of parieto-occipital cerebral activity during the retention of visual information was related to performance in 2 standardized mathematical tasks: mathematical reasoning and calculation fluency. The findings show that brain activity during retention period of a VSTM task is associated with mathematical abilities. Contributions of VSTM processes to numerical cognition should be considered in cognitive interventions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Principal tools for exploring the brain and mapping its activity

    International Nuclear Information System (INIS)

    Mazoyer, B.; Mashaal, M.

    1996-01-01

    The electro-encephalography (EEG), magneto-encephalography (MEG), scanner, positron computed tomography, single photon emission computed tomography (SPECT) and NMR imaging are the main methods used to explore human brain and to do a mapping of its activity. These methods are described into details (principle, visualization, uses, advantages, disadvantages). They can be useful to detect the possible anomalies of the human brain. (O.M.)

  1. Intraoperative Functional Ultrasound Imaging of Human Brain Activity

    OpenAIRE

    Imbault, Marion; Chauvet, Dorian; Gennisson, Jean-Luc; Capelle, Laurent; Tanter, Mickael

    2017-01-01

    International audience; The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz), fUS is performed during surgery to measure transient changes in cerebral blood volume with a high spatiotemporal resoluti...

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

    Directory of Open Access Journals (Sweden)

    Yong He

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

  3. Plug&Play Brain-Computer Interfaces for effective Active and Assisted Living control.

    Science.gov (United States)

    Mora, Niccolò; De Munari, Ilaria; Ciampolini, Paolo; Del R Millán, José

    2017-08-01

    Brain-Computer Interfaces (BCI) rely on the interpretation of brain activity to provide people with disabilities with an alternative/augmentative interaction path. In light of this, BCI could be considered as enabling technology in many fields, including Active and Assisted Living (AAL) systems control. Interaction barriers could be removed indeed, enabling user with severe motor impairments to gain control over a wide range of AAL features. In this paper, a cost-effective BCI solution, targeted (but not limited) to AAL system control is presented. A custom hardware module is briefly reviewed, while signal processing techniques are covered in more depth. Steady-state visual evoked potentials (SSVEP) are exploited in this work as operating BCI protocol. In contrast with most common SSVEP-BCI approaches, we propose the definition of a prediction confidence indicator, which is shown to improve overall classification accuracy. The confidence indicator is derived without any subject-specific approach and is stable across users: it can thus be defined once and then shared between different persons. This allows some kind of Plug&Play interaction. Furthermore, by modelling rest/idle periods with the confidence indicator, it is possible to detect active control periods and separate them from "background activity": this is capital for real-time, self-paced operation. Finally, the indicator also allows to dynamically choose the most appropriate observation window length, improving system's responsiveness and user's comfort. Good results are achieved under such operating conditions, achieving, for instance, a false positive rate of 0.16 min -1 , which outperform current literature findings.

  4. 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.

  5. Working memory training: improving intelligence--changing brain activity.

    Science.gov (United States)

    Jaušovec, Norbert; Jaušovec, Ksenija

    2012-07-01

    The main objectives of the study were: to investigate whether training on working memory (WM) could improve fluid intelligence, and to investigate the effects WM training had on neuroelectric (electroencephalography - EEG) and hemodynamic (near-infrared spectroscopy - NIRS) patterns of brain activity. In a parallel group experimental design, respondents of the working memory group after 30 h of training significantly increased performance on all tests of fluid intelligence. By contrast, respondents of the active control group (participating in a 30-h communication training course) showed no improvements in performance. The influence of WM training on patterns of neuroelectric brain activity was most pronounced in the theta and alpha bands. Theta and lower-1 alpha band synchronization was accompanied by increased lower-2 and upper alpha desynchronization. The hemodynamic patterns of brain activity after the training changed from higher right hemispheric activation to a balanced activity of both frontal areas. The neuroelectric as well as hemodynamic patterns of brain activity suggest that the training influenced WM maintenance functions as well as processes directed by the central executive. The changes in upper alpha band desynchronization could further indicate that processes related to long term memory were also influenced. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Individual Variability in Brain Activity: A Nuisance or an Opportunity?

    Science.gov (United States)

    Van Horn, John Darrell; Grafton, Scott T; Miller, Michael B

    2008-12-01

    Functional imaging research has been heavily influenced by results based on population-level inference. However, group average results may belie the unique patterns of activity present in the individual that ordinarily are considered random noise. Recent advances in the evolution of MRI hardware have led to significant improvements in the stability and reproducibility of blood oxygen level dependent (BOLD) measurements. These enhancements provide a unique opportunity for closer examination of individual patterns of brain activity. Three objectives can be accomplished by considering brain scans at the individual level; (1) Mapping functional anatomy at a fine grained analysis; (2) Determining if an individual scan is normative with respect to a reference population; and (3) Understanding the sources of intersubject variability in brain activity. In this review, we detail these objectives, briefly discuss their histories and present recent trends in the analyses of individual variability. Finally, we emphasize the unique opportunities and challenges for understanding individual differences through international collaboration among Pacific Rim investigators.

  8. Brain feminization requires active repression of masculinization via DNA methylation

    Science.gov (United States)

    Nugent, Bridget M.; Wright, Christopher L.; Shetty, Amol C.; Hodes, Georgia E.; Lenz, Kathryn M.; Mahurkar, Anup; Russo, Scott J.; Devine, Scott E.; McCarthy, Margaret M.

    2015-01-01

    The developing mammalian brain is destined for a female phenotype unless exposed to gonadal hormones during a perinatal sensitive period. It has been assumed that the undifferentiated brain is masculinized by direct induction of transcription by ligand-activated nuclear steroid receptors. We found that a primary effect of gonadal steroids in the highly sexually-dimorphic preoptic area (POA) is to reduce activity of DNA methyltransferase (Dnmt) enzymes, thereby decreasing DNA methylation and releasing masculinizing genes from epigenetic repression. Pharmacological inhibition of Dnmts mimicked gonadal steroids, resulting in masculinized neuronal markers and male sexual behavior in females. Conditional knockout of the de novo Dnmt isoform, Dnmt3a, also masculinized sexual behavior in female mice. RNA sequencing revealed gene and isoform variants modulated by methylation that may underlie the divergent reproductive behaviors of males versus females. Our data show that brain feminization is maintained by the active suppression of masculinization via DNA methylation. PMID:25821913

  9. Visceral Inflammation and Immune Activation Stress the Brain

    Science.gov (United States)

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

    2017-01-01

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

  10. On a Mathematical Model of Brain Activities

    International Nuclear Information System (INIS)

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

    2007-01-01

    The procedure of recognition can be described as follows: There is a set of complex signals stored in the memory. Choosing one of these signals may be interpreted as generating a hypothesis concerning an 'expexted view of the world'. Then the brain compares a signal arising from our senses with the signal chosen from the memory leading to a change of the state of both signals. Furthermore, measurements of that procedure like EEG or MEG are based on the fact that recognition of signals causes a certain loss of excited neurons, i.e. the neurons change their state from 'excited' to 'nonexcited'. For that reason a statistical model of the recognition process should reflect both--the change of the signals and the loss of excited neurons. A first attempt to explain the process of recognition in terms of quantum statistics was given. In the present note it is not possible to present this approach in detail. In lieu we will sketch roughly a few of the basic ideas and structures of the proposed model of the recognition process (Section). Further, we introduce the basic spaces and justify the choice of spaces used in this approach. A more elaborate presentation including all proofs will be given in a series of some forthcoming papers. In this series also the procedures of creation of signals from the memory, amplification, accumulation and transformation of input signals, and measurements like EEG and MEG will be treated in detail

  11. Supplementation of American ginseng berry extract mitigated cisplatin-evoked nephrotoxicity by suppressing ROS-mediated activation of MAPK and NF-κB signaling pathways.

    Science.gov (United States)

    Ma, Zhi-Na; Liu, Zhi; Wang, Zi; Ren, Shen; Tang, Shan; Wang, Ying-Ping; Xiao, Sheng-Yuan; Chen, Chen; Li, Wei

    2017-12-01

    Nephrotoxicity induced by cisplatin in 30% of all cisplatin treated patients seriously limits its clinical implication as a widely used anticancer agent, and may even cause patients to alter or give up cisplatin therapy. The purpose of this study is to test a protective effect of American ginseng berry extract (AGBE) on cisplatin-induced nephrotoxicity in mice. In this study, the histopathological changes and elevated levels of serum creatinine (CRE) and urea nitrogen (BUN) caused by cisplatin were significantly diminished by AGBE treatment. Oxidative stress caused by cisplatin, evidenced by increases in kidney tissues malondialdehyde (MDA) content, cytochrome P450 E1 (CYP2E1), renal 4-hydroxynonenal (4-HNE) levels and decreases of glutathione (GSH) and superoxide dismutase (SOD) contents, was significantly ameliorated by AGBE pretreatment. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were inhibited by AGBE treatment, suggesting a suppression of inflammatory response. Additionally, AGBE clearly inhibited cisplatin-induced activations of nuclear factor-kappa B (NF-κB) and mitogen activated protein kinase (MAPK) signal pathways. Supplementation of cisplatin-intoxicated mice with AGBE also significantly reduced apoptotic protein levels of Bax, cleaved caspase-3, cytochrome c and increased anti-apoptotic protein Bcl-2. These findings highlight nephroprotective effect of AGBE against cisplatin-evoked nephrotoxicity through ROS-mediated MAPK and NF-κB signaling pathways. Copyright © 2017. Published by Elsevier Ltd.

  12. Assessment of D-methionine protecting cisplatin-induced otolith toxicity by vestibular-evoked myogenic potential tests, ATPase activities and oxidative state in guinea pigs.

    Science.gov (United States)

    Lo, Wu-Chia; Chang, Chih-Ming; Liao, Li-Jen; Wang, Chi-Te; Young, Yi-Ho; Chang, Yih-Leong; Cheng, Po-Wen

    2015-01-01

    To date, inadequate study has been devoted to the toxic vestibular effects caused by cisplatin. In addition, no electrophysiological examination has been conducted to assess cisplatin-induced otolith toxicity. The purposes of this study are thus two-fold: 1) to determine whether cervical vestibular-evoked myogenic potentials (VEMPs) and ocular VEMPs are practical electrophysiological methods of testing for cisplatin-induced otolith toxicity and 2) to examine if D-methionine (D-met) pre-injection would protect the otolith organs against cisplatin-induced changes in enzyme activities and/or oxidative status. Guinea pigs were intraperitoneally treated once daily with the following injections for seven consecutive days: sterile 0.9% saline control, cisplatin (5 mg/kg) only, D-met (300 mg/kg) only, or a combination of d-met (300 mg/kg) and cisplatin (5 mg/kg), respectively, with a 30 minute window in between. Each animal underwent the oVEMP and cVEMP tests before and after treatment. The changes in the biochemistry of the otolith organs, including membranous Na(+), K(+)-ATPase and Ca(2+)-ATPase, lipid peroxidation (LPO) levels and nitric oxide (NO) levels, were also evaluated. In the cisplatin-only treated guinea pigs, the mean amplitudes of the oVEMP tests were significantly (potolith dysfunction. D-Met attenuated the reduced ATPase activities and increased oxidative stress induced by cisplatin toxicity in the otolith organs. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Potenciais evocados auditivos de tronco encefálico de ex-usuários de drogas Brain stem evoked response audiometry of former drug users

    Directory of Open Access Journals (Sweden)

    Tainara Milbradt Weich

    2012-10-01

    Full Text Available As drogas ilícitas são conhecidas pelos seus efeitos deletérios no sistema nervoso central; no entanto, elas também podem atingir o sistema auditivo, provocando alterações. OBJETIVOS: Analisar e comparar os resultados dos potenciais evocados auditivos de tronco encefálico (PEATE de frequentadores de grupos de apoio a ex-usuários de drogas. MÉTODO: Estudo transversal, não experimental, descritivo e quantitativo. A amostra foi composta por 17 indivíduos divididos conforme o tipo de droga mais consumida: 10 indivíduos no grupo maconha (G1 e sete no grupo crack/cocaína (G2. Eles foram subdivididos pelo tempo de uso de drogas: um a cinco anos, seis a 10 anos e mais que 15 anos. A avaliação foi feita por meio de anamnese, audiometria tonal liminar, medidas de imitância acústica e PEATE. RESULTADOS: Ao comparar os resultados de G1 e G2, independente do tempo de uso de drogas, não se observou diferença estatisticamente significante nas latências absolutas e nos intervalos interpicos. No entanto, apenas cinco dos 17 indivíduos tiveram PEATE com resultados adequados para a faixa etária. CONCLUSÃO: Independentemente do tempo de utilização das drogas, o uso de maconha e crack/cocaína pode provocar alterações difusas no tronco encefálico, comprometendo a transmissão do estímulo auditivo.Illicit drugs are known for their deleterious effects upon the central nervous system and more specifically for how they adversely affect hearing. OBJECTIVE: This study aims to analyze and compare the hearing complaints and the results of brainstem evoked response audiometry (BERA of former drug user support group goers. METHODS: This is a cross-sectional non-experimental descriptive quantitative study. The sample consisted of 17 subjects divided by their preferred drug of use. Ten individuals were placed in the marijuana group (G1 and seven in the crack/cocaine group (G2. The subjects were further divided based on how long they had been using

  14. Astrocyte-derived CCL2 participates in surgery-induced cognitive dysfunction and neuroinflammation via evoking microglia activation.

    Science.gov (United States)

    Xu, Jiawen; Dong, Hongquan; Qian, Qingqing; Zhang, Xiang; Wang, Yiwei; Jin, Wenjie; Qian, Yanning

    2017-08-14

    Neuroinflammation induced by peripheral trauma plays a key role in the development of postoperative cognitive dysfunction (POCD). Substantial evidence points to reactive glia as a pivotal factor during the inflammation process. However, little is known about the functional interactions between astrocytes and microglia. Recent evidence suggests the involvement of the CCL2-CCR2 pathway in CNS inflammation-related diseases. Our previous studies have suggested that astrocyte-derived CCL2 can induce microglial activation in vitro. Within this context, we sought to determine if the CCL2/CCR2 axis is involved in the crosstalk between astrocytes and microglia, contributing to increased neuroinflammation. Here, we show that tibial fracture surgery promoted CCL2 upregulation in activated astrocytes, increased CCR2 expression in activated microglia, and induced deficits in learning and memory. Site-directed pre-injection of RS504393, a CCR2 antagonist, inhibited this effect by reducing microglial activation, M1 polarization, inflammatory cytokines, and neuronal injury and death and improving cognitive function. Taken together, these data implicate CCL2-CCR2 signaling in astrocyte-mediated microglial activation in central nervous system (CNS) inflammation and suggest that interference with CCL2 signaling could constitute another potential therapeutic target for POCD. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Contribution of α-adrenoceptors to depolarization and contraction evoked by continuous asynchronous sympathetic nerve activity in rat tail artery

    Science.gov (United States)

    Brock, J A; McLachlan, E M; Rayner, S E

    1997-01-01

    The effects of continuous but asynchronous nerve activity induced by ciguatoxin (CTX-1) on the membrane potential and contraction of smooth muscle cells have been investigated in rat proximal tail arteries isolated in vitro. These effects have been compared with those produced by the continuous application of phenylephrine (PE).CTX-1 (0.4 nM) and PE (10 μM) produced a maintained depolarization of the arterial smooth muscle that was almost completely blocked by α-adrenoceptor blockade. In both cases, the depolarization was more sensitive to the selective α2-adrenoceptor antagonist, idazoxan (0.1 μM), than to the selective α1-adrenoceptor antagonist, prazosin (0.01 μM).In contrast, the maintained contraction of the tail artery induced by CTX-1 (0.2 nM) and PE (2 and 10 μM) was more sensitive to prazosin (0.01) μM, than to idazoxan (0.01 μM). In combination, these antagonists almost completely inhibited contraction to both agents.Application of the calcium channel antagonist, nifedipine (1 μM), had no effect on the depolarization induced by either CTX-1 or PE but maximally reduced the force of the maintained contraction to both agents by about 50%.We conclude that the constriction of the tail artery induced by CTX-1, which mimics the natural discharge of postganglionic perivascular axons, is due almost entirely to α-adrenoceptor activation. The results indicate that neuronally released noradrenaline activates more than one α-adrenoceptor subtype. The depolarization is dependent primarily on α2-adrenoceptor activation whereas the contraction is dependent primarily on α1-adrenoceptor activation. The links between α-adrenoceptor activation and the voltage-dependent and voltage-independent mechanisms that deliver Ca2+ to the contractile apparatus appear to be complex. PMID:9113373

  16. Quantification of task-dependent cortical activation evoked by robotic continuous wrist joint manipulation in chronic hemiparetic stroke

    NARCIS (Netherlands)

    Vlaar, M.P.; Solis Escalante, T.; Dewald, J.P.A.; Van Wegen, Erwin E H; Schouten, A.C.; Kwakkel, G.; van der Helm, F.C.T.

    2017-01-01

    Background: Cortical damage after stroke can drastically impair sensory and motor function of the upper limb, affecting the execution of activities of daily living and quality of life. Motor impairment after stroke has been thoroughly studied, however sensory impairment and its relation to movement

  17. Altered brain activation during response inhibition in obstructive sleep apnea.

    Science.gov (United States)

    Ayalon, Liat; Ancoli-Israel, Sonia; Drummond, Sean Pa

    2009-06-01

    This study examined response inhibition during a Go-NoGo task in individuals with obstructive sleep apnea (OSA). Fourteen OSA patients and 14 controls were studied with functional magnetic resonance imaging. Compared to controls, the OSA group showed more false positives (error of commission) during the NoGo trials with decreased brain activation in the left postcentral gyrus, cingulate gyrus and inferior parietal lobe, as well as right insula and putamen. This is consistent with previous findings of impaired performance and decreased brain activation in OSA patients during a working memory task, suggesting that compromised brain function in response to cognitive challenges may underlie some of the cognitive deficits seen in patients with OSA.

  18. Brain activation studies with PET and functional MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-01

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

  19. 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

  20. Evoked Potentials and Memory/Cognition Tests Validate Brain Atrophy as Measured by 3T MRI (NeuroQuant) in Cognitively Impaired Patients

    Science.gov (United States)

    Braverman, Eric R.; Blum, Kenneth; Hussman, Karl L.; Han, David; Dushaj, Kristina; Li, Mona; Marin, Gabriela; Badgaiyan, Rajendra D.; Smayda, Richard; Gold, Mark S.

    2015-01-01

    To our knowledge, this is the largest study evaluating relationships between 3T Magnetic Resonance Imaging (MRI) and P300 and memory/cognitive tests in the literature. The 3T MRI using NeuroQuant has an increased resolution 15 times that of 1.5T MRI. Utilizing NeuroQuant 3T MRI as a diagnostic tool in primary care, subjects (N=169; 19–90 years) displayed increased areas of anatomical atrophy: 34.62% hippocampal atrophy (N=54), 57.14% central atrophy (N=88), and 44.52% temporal atrophy (N=69). A majority of these patients exhibited overlap in measured areas of atrophy and were cognitively impaired. These results positively correlated with decreased P300 values and WMS-III (WMS-III) scores differentially across various brain loci. Delayed latency (p=0.0740) was marginally associated with temporal atrophy; reduced fractional anisotropy (FA) in frontal lobes correlated with aging, delayed P300 latency, and decreased visual and working memory (p=0.0115). Aging and delayed P300 latency correlated with lower FA. The correlation between working memory and reduced FA in frontal lobes is marginally significant (p=0.0787). In the centrum semiovale (CS), reduced FA correlated with visual memory (p=0.0622). Lower demyelination correlated with higher P300 amplitude (p=0.0002). Compared to males, females have higher demyelination (p=0.0064). Along these lines, the higher the P300 amplitude, the lower the bilateral atrophy (p=0.0165). Hippocampal atrophy correlated with increased auditory memory and gender, especially in males (p=0.0087). In considering temporal lobe atrophy correlations: delayed P300 latency and high temporal atrophy (p=0.0740); high auditory memory and low temporal atrophy (p=0.0417); and high working memory and low temporal atrophy (p=0.0166). Central atrophy correlated with aging and immediate memory (p=0.0294): the higher the immediate memory, the lower the central atrophy. Generally, the validation of brain atrophy by P300 and WMS-III could lead to cost

  1. Evoked Potentials and Memory/Cognition Tests Validate Brain Atrophy as Measured by 3T MRI (NeuroQuant in Cognitively Impaired Patients.

    Directory of Open Access Journals (Sweden)

    Eric R Braverman

    Full Text Available To our knowledge, this is the largest study evaluating relationships between 3T Magnetic Resonance Imaging (MRI and P300 and memory/cognitive tests in the literature. The 3T MRI using NeuroQuant has an increased resolution 15 times that of 1.5T MRI. Utilizing NeuroQuant 3T MRI as a diagnostic tool in primary care, subjects (N=169; 19-90 years displayed increased areas of anatomical atrophy: 34.62% hippocampal atrophy (N=54, 57.14% central atrophy (N=88, and 44.52% temporal atrophy (N=69. A majority of these patients exhibited overlap in measured areas of atrophy and were cognitively impaired. These results positively correlated with decreased P300 values and WMS-III (WMS-III scores differentially across various brain loci. Delayed latency (p=0.0740 was marginally associated with temporal atrophy; reduced fractional anisotropy (FA in frontal lobes correlated with aging, delayed P300 latency, and decreased visual and working memory (p=0.0115. Aging and delayed P300 latency correlated with lower FA. The correlation between working memory and reduced FA in frontal lobes is marginally significant (p=0.0787. In the centrum semiovale (CS, reduced FA correlated with visual memory (p=0.0622. Lower demyelination correlated with higher P300 amplitude (p=0.0002. Compared to males, females have higher demyelination (p=0.0064. Along these lines, the higher the P300 amplitude, the lower the bilateral atrophy (p=0.0165. Hippocampal atrophy correlated with increased auditory memory and gender, especially in males (p=0.0087. In considering temporal lobe atrophy correlations: delayed P300 latency and high temporal atrophy (p=0.0740; high auditory memory and low temporal atrophy (p=0.0417; and high working memory and low temporal atrophy (p=0.0166. Central atrophy correlated with aging and immediate memory (p=0.0294: the higher the immediate memory, the lower the central atrophy. Generally, the validation of brain atrophy by P300 and WMS-III could lead to cost

  2. Evoked Potentials and Memory/Cognition Tests Validate Brain Atrophy as Measured by 3T MRI (NeuroQuant) in Cognitively Impaired Patients.

    Science.gov (United States)

    Braverman, Eric R; Blum, Kenneth; Hussman, Karl L; Han, David; Dushaj, Kristina; Li, Mona; Marin, Gabriela; Badgaiyan, Rajendra D; Smayda, Richard; Gold, Mark S

    2015-01-01

    To our knowledge, this is the largest study evaluating relationships between 3T Magnetic Resonance Imaging (MRI) and P300 and memory/cognitive tests in the literature. The 3T MRI using NeuroQuant has an increased resolution 15 times that of 1.5T MRI. Utilizing NeuroQuant 3T MRI as a diagnostic tool in primary care, subjects (N=169; 19-90 years) displayed increased areas of anatomical atrophy: 34.62% hippocampal atrophy (N=54), 57.14% central atrophy (N=88), and 44.52% temporal atrophy (N=69). A majority of these patients exhibited overlap in measured areas of atrophy and were cognitively impaired. These results positively correlated with decreased P300 values and WMS-III (WMS-III) scores differentially across various brain loci. Delayed latency (p=0.0740) was marginally associated with temporal atrophy; reduced fractional anisotropy (FA) in frontal lobes correlated with aging, delayed P300 latency, and decreased visual and working memory (p=0.0115). Aging and delayed P300 latency correlated with lower FA. The correlation between working memory and reduced FA in frontal lobes is marginally significant (p=0.0787). In the centrum semiovale (CS), reduced FA correlated with visual memory (p=0.0622). Lower demyelination correlated with higher P300 amplitude (p=0.0002). Compared to males, females have higher demyelination (p=0.0064). Along these lines, the higher the P300 amplitude, the lower the bilateral atrophy (p=0.0165). Hippocampal atrophy correlated with increased auditory memory and gender, especially in males (p=0.0087). In considering temporal lobe atrophy correlations: delayed P300 latency and high temporal atrophy (p=0.0740); high auditory memory and low temporal atrophy (p=0.0417); and high working memory and low temporal atrophy (p=0.0166). Central atrophy correlated with aging and immediate memory (p=0.0294): the higher the immediate memory, the lower the central atrophy. Generally, the validation of brain atrophy by P300 and WMS-III could lead to cost

  3. Differential brain network activity across mood states in bipolar disorder.

    Science.gov (United States)

    Brady, Roscoe O; Tandon, Neeraj; Masters, Grace A; Margolis, Allison; Cohen, Bruce M; Keshavan, Matcheri; Öngür, Dost

    2017-01-01

    This study aimed to identify how the activity of large-scale brain networks differs between mood states in bipolar disorder. The authors measured spontaneous brain activity in subjects with bipolar disorder in mania and euthymia and compared these states to a healthy comparison population. 23 subjects with bipolar disorder type I in a manic episode, 24 euthymic bipolar I subjects, and 23 matched healthy comparison (HC) subjects underwent resting state fMRI scans. Using an existing parcellation of the whole brain, we measured functional connectivity between brain regions and identified significant differences between groups. In unbiased whole-brain analyses, functional connectivity between parietal, occipital, and frontal nodes within the dorsal attention network (DAN) were significantly greater in mania than euthymia or HC subjects. In the default mode network (DMN), connectivity between dorsal frontal nodes and the rest of the DMN differentiated both mood state and diagnosis. The bipolar groups were separate cohorts rather than subjects imaged longitudinally across mood states. Bipolar mood states are associated with highly significant alterations in connectivity in two large-scale brain networks. These same networks also differentiate bipolar mania and euthymia from a HC population. State related changes in DAN and DMN connectivity suggest a circuit based pathology underlying cognitive dysfunction as well as activity/reactivity in bipolar mania. Altered activities in neural networks may be biomarkers of bipolar disorder diagnosis and mood state that are accessible to neuromodulation and are promising novel targets for scientific investigation and possible clinical intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Nishimura, Masahiko; Yoshii, Yoshihiko; Hyodo, Akio; Sugimoto, Koichi; Tsuchida, Yukihiro; Yonaha, Hirokatsu; Ito, Koichi

    2007-01-01

    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)

  5. Immature pattern of brain activity in Rett syndrome

    DEFF Research Database (Denmark)

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

    1990-01-01

    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...

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

    Science.gov (United States)

    Jausovec, Norbert; Jausovec, Ksenija

    2012-01-01

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

  7. 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…

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

    African Journals Online (AJOL)

    JTEkanem

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

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

    African Journals Online (AJOL)

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

  10. Activating Nrf-2 signaling depresses unilateral ureteral obstruction-evoked mitochondrial stress-related autophagy, apoptosis and pyroptosis in kidney.

    Directory of Open Access Journals (Sweden)

    Shue Dong Chung

    Full Text Available Exacerbated oxidative stress and inflammation may induce three types of programmed cell death, autophagy, apoptosis and pyroptosis in unilateral ureteral obstruction (UUO kidney. Sulforaphane activating NF-E2-related nuclear factor erythroid-2 (Nrf-2 signaling may ameliorate UUO-induced renal damage. UUO was induced in the left kidney of female Wistar rats. The level of renal blood flow, cortical and medullary oxygen tension and reactive oxygen species (ROS was evaluated. Fibrosis, ED-1 (macrophage/monocyte infiltration, oxidative stress, autophagy, apoptosis and pyroptosis were evaluated by immunohistochemistry and Western blot in UUO kidneys. Effects of sulforaphane, an Nrf-2 activator, on Nrf-2- and mitochondrial stress-related proteins and renal injury were examined. UUO decreased renal blood flow and oxygen tension and increased renal ROS, 3-nitrotyrosine stain, ED-1 infiltration and fibrosis. Enhanced renal tubular Beclin-1 expression started at 4 h UUO and further enhanced at 3d UUO, whereas increased Atg-5-Atg12 and LC3-II expression were found at 3d UUO. Increased renal Bax/Bcl-2 ratio, caspase 3 and PARP fragments, apoptosis formation associated with increased caspase 1 and IL-1β expression for pyroptosis formation were started from 3d UUO. UUO reduced nuclear Nrf-2 translocation, increased cytosolic and inhibitory Nrf-2 expression, increased cytosolic Bax translocation to mitochondrial and enhanced mitochondrial Cytochrome c release into cytosol of the UUO kidneys. Sulforaphane significantly increased nuclear Nrf-2 translocation and decreased mitochondrial Bax translocation and Cytochrome c release into cytosol resulting in decreased renal injury. In conclusion, sulforaphane via activating Nrf-2 signaling preserved mitochondrial function and suppressed UUO-induced renal oxidative stress, inflammation, fibrosis, autophagy, apoptosis and pyroptosis.

  11. Effect of a temperature increase in the non-noxious range on proton-evoked ASIC and TRPV1 activity.

    Science.gov (United States)

    Blanchard, Maxime G; Kellenberger, Stephan

    2011-01-01

    Acid-sensing ion channels (ASICs) are neuronal H(+)-gated cation channels, and the transient receptor potential vanilloid 1 channel (TRPV1) is a multimodal cation channel activated by low pH, noxious heat, capsaicin, and voltage. ASICs and TRPV1 are present in sensory neurons. It has been shown that raising the temperature increases TRPV1 and decreases ASIC H(+)-gated current amplitudes. To understand the underlying mechanisms, we have analyzed ASIC and TRPV1 function in a recombinant expression system and in dorsal root ganglion (DRG) neurons at room and physiological temperature. We show that temperature in the range studied does not affect the pH dependence of ASIC and TRPV1 activation. A temperature increase induces, however, a small alkaline shift of the pH dependence of steady-state inactivation of ASIC1a, ASIC1b, and ASIC2a. The decrease in ASIC peak current amplitudes at higher temperatures is likely in part due to the observed accelerated open channel inactivation kinetics and for some ASIC types to the changed pH dependence of steady-state inactivation. The increase in H(+)-activated TRPV1 current at the higher temperature is at least in part due to a hyperpolarizing shift in its voltage dependence. The contribution of TRPV1 relative to ASICs to H(+)-gated currents in DRG neurons increases with higher temperature and acidity. Still, ASICs remain the principal pH sensors of DRG neurons at 35°C in the pH range ≥6.

  12. Menopause-related brain activation patterns during visual sexual arousal in menopausal women: An fMRI pilot study using time-course analysis.

    Science.gov (United States)

    Kim, Gwang-Won; Jeong, Gwang-Woo

    2017-02-20

    The aging process and menopausal transition are important factors in sexual dysfunction of menopausal women. No neuroimaging study has assessed the age- and menopause-related changes on brain activation areas associated with sexual arousal in menopausal women. The purpose of this study was to evaluate the time course of regional brain activity associated with sexual arousal evoked by visual stimulation in premenopausal and menopausal women, and further to assess the effect of menopause on the brain areas associated with sexual arousal in menopausal women using functional magnetic resonance imaging (fMRI). Thirty volunteers consisting of 15 premenopausal and 15 menopausal women underwent the fMRI. For the activation condition, volunteers viewed sexually arousing visual stimulation. The brain areas with significantly higher activation in premenopausal women compared with menopausal women included the thalamus, amygdala, and anterior cingulate cortex (ACC) using analysis of covariance adjusting for age (pchanges in the amygdala while viewing erotic video were positively correlated with estrogen levels in the two groups. Our findings suggest that reduced brain activity of the thalamus, amygdala, and ACC in menopausal women may be associated with menopause-related decrease in sexual arousal. These findings might help elucidate the neural mechanisms associated with sexual dysfunction in menopausal women. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2018-02-27

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

  14. You can count on the motor cortex: Finger counting habits modulate motor cortex activation evoked by numbers

    Science.gov (United States)

    Tschentscher, Nadja; Hauk, Olaf; Fischer, Martin H.; Pulvermüller, Friedemann

    2012-01-01

    The embodied cognition framework suggests that neural systems for perception and action are engaged during higher cognitive processes. In an event-related fMRI study, we tested this claim for the abstract domain of numerical symbol processing: is the human cortical motor system part of the representation of numbers, and is organization of numerical knowledge influenced by individual finger counting habits? Developmental studies suggest a link between numerals and finger counting habits due to the acquisition of numerical skills through finger counting in childhood. In the present study, digits 1 to 9 and the corresponding number words were presented visually to adults with different finger counting habits, i.e. left- and right-starters who reported that they usually start counting small numbers with their left and right hand, respectively. Despite the absence of overt hand movements, the hemisphere contralateral to the hand used for counting small numbers was activated when small numbers were presented. The correspondence between finger counting habits and hemispheric motor activation is consistent with an intrinsic functional link between finger counting and number processing. PMID:22133748

  15. Participation in leisure activities during brain injury rehabilitation.

    Science.gov (United States)

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

    2011-01-01

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

  16. Laterality of Brain Activation for Risk Factors of Addiction.

    Science.gov (United States)

    Gordon, Harold W

    2016-01-01

    Laterality of brain activation is reported for tests of risk factors of addiction- impulsivity and craving-but authors rarely address the potential significance of those asymmetries. The purpose of this study is to demonstrate this laterality and discuss its relevance to cognitive and neurophysiological asymmetries associated with drug abuse vulnerability in order to provide new insights for future research in drug abuse. From published reports, brain areas of activation for two tests of response inhibition or craving for drugs of abuse were compiled from fMRI activation peaks and were tabulated for eight sections (octants) in each hemisphere. Percent asymmetries were calculated (R-L/R+L) across studies for each area. For impulsivity, most activation peaks favored the right hemisphere. Overall, the percent difference was 32% (Χ2 = 16.026; p laterality into consideration is a missed opportunity in designing studies and gaining insight into the etiology of drug abuse and pathways for treatment.

  17. Amygdala lesions disrupt modulation of functional MRI activity evoked by facial expression in the monkey inferior temporal cortex

    Science.gov (United States)

    Hadj-Bouziane, Fadila; Liu, Ning; Bell, Andrew H.; Gothard, Katalin M.; Luh, Wen-Ming; Tootell, Roger B. H.; Murray, Elisabeth A.; Ungerleider, Leslie G.

    2012-01-01

    We previously showed that facial expressions modulate functional MRI activity in the face-processing regions of the macaque monkey’s amygdala and inferior temporal (IT) cortex. Specifically, we showed that faces expressing emotion yield greater activation than neutral faces; we term this difference the “valence effect.” We hypothesized that amygdala lesions would disrupt the valence effect by eliminating the modulatory feedback from the amygdala to the IT cortex. We compared the valence effects within the IT cortex in monkeys with excitotoxic amygdala lesions (n = 3) with those in intact control animals (n = 3) using contrast agent-based functional MRI at 3 T. Images of four distinct monkey facial expressions—neutral, aggressive (open mouth threat), fearful (fear grin), and appeasing (lip smack)—were presented to the subjects in a blocked design. Our results showed that in monkeys with amygdala lesions the valence effects were strongly disrupted within the IT cortex, whereas face responsivity (neutral faces > scrambled faces) and face selectivity (neutral faces > non-face objects) were unaffected. Furthermore, sparing of the anterior amygdala led to intact valence effects in the anterior IT cortex (which included the anterior face-selective regions), whereas sparing of the posterior amygdala led to intact valence effects in the posterior IT cortex (which included the posterior face-selective regions). Overall, our data demonstrate that the feedback projections from the amygdala to the IT cortex mediate the valence effect found there. Moreover, these modulatory effects are consistent with an anterior-to-posterior gradient of projections, as suggested by classical tracer studies. PMID:23184972

  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...

  19. Learning sculpts the spontaneous activity of the resting human brain

    OpenAIRE

    Lewis, Christopher M.; Baldassarre, Antonello; Committeri, Giorgia; Romani, Gian Luca; Corbetta, Maurizio

    2009-01-01

    The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brai...

  20. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

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

    Science.gov (United States)

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

    2009-04-01

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

  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. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

    Directory of Open Access Journals (Sweden)

    Ong John M

    2007-03-01

    Full Text Available Abstract Background The blood-brain tumor barrier (BTB impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB permeability in brain tumors, but not in normal brain. Iberiotoxin, a KCa channel antagonist, significantly attenuated NS1619-induced BTB permeability increase. We found KCa channels and bradykinin type 2 receptors (B2R expressed in cultured human metastatic brain tumor cells (CRL-5904, non-small cell lung cancer, metastasized to brain, human brain microvessel endothelial cells (HBMEC and human lung cancer brain metastasis tissues. Potentiometric assays demonstrated the activity of KCa channels in metastatic brain tumor cells and HBMEC. Furthermore, we detected higher expression of KCa channels in the metastatic brain tumor tissue and tumor capillary endothelia as compared to normal brain tissue. Co-culture of metastatic brain tumor cells and brain microvessel endothelial cells showed an upregulation of KCa channels, which may contribute to the overexpression of KCa channels in tumor microvessels and selectivity of BTB opening. Conclusion These findings suggest that KCa channels in metastatic brain tumors may serve as an effective target for biochemical modulation of BTB permeability to enhance selective delivery of chemotherapeutic drugs to metastatic brain tumors.

  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. Brain Activity at the Embryonic Stages of Development

    Directory of Open Access Journals (Sweden)

    D.R. Akhmetshina

    2015-06-01

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

  6. 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.

  7. Central GLP-1 receptor activation modulates cocaine-evoked phasic dopamine signaling in the nucleus accumbens core.

    Science.gov (United States)

    Fortin, Samantha M; Roitman, Mitchell F

    2017-07-01

    Drugs of abuse increase the frequency and magnitude of brief (1-3s), high concentration (phasic) dopamine release events in terminal regions. These are thought to be a critical part of drug reinforcement and ultimately the development of addiction. Recently, metabolic regulatory peptides, including the satiety signal glucagon-like peptide-1 (GLP-1), have been shown to modulate cocaine reward-driven behavior and sustained dopamine levels after cocaine administration. Here, we use fast-scan cyclic voltammetry (FSCV) to explore GLP-1 receptor (GLP-1R) modulation of dynamic dopamine release in the nucleus accumbens (NAc) during cocaine administration. We analyzed dopamine release events in both the NAc shell and core, as these two subregions are differentially affected by cocaine and uniquely contribute to motivated behavior. We found that central delivery of the GLP-1R agonist Exendin-4 suppressed the induction of phasic dopamine release events by intravenous cocaine. This effect was selective for dopamine signaling in the NAc core. Suppression of phasic signaling in the core by Exendin-4 could not be attributed to interference with cocaine binding to one of its major substrates, the dopamine transporter, as cocaine-induced increases in reuptake were unaffected. The results suggest that GLP-1R activation, instead, exerts its suppressive effects by altering dopamine release - possibly by suppressing the excitability of dopamine neurons. Given the role of NAc core dopamine in the generation of conditioned responses based on associative learning, suppression of cocaine-induced dopamine signaling in this subregion by GLP-1R agonism may decrease the reinforcing properties of cocaine. Thus, GLP-1Rs remain viable targets for the treatment and prevention of cocaine seeking, taking and relapse. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Environmental CO2 inhibits Caenorhabditis elegans egg-laying by modulating olfactory neurons and evokes widespread changes in neural activity

    Science.gov (United States)

    Fenk, Lorenz A.; de Bono, Mario

    2015-01-01

    Carbon dioxide (CO2) gradients are ubiquitous and provide animals with information about their environment, such as the potential presence of prey or predators. The nematode Caenorhabditis elegans avoids elevated CO2, and previous work identified three neuron pairs called “BAG,” “AFD,” and “ASE” that respond to CO2 stimuli. Using in vivo Ca2+ imaging and behavioral analysis, we show that C. elegans can detect CO2 independently of these sensory pathways. Many of the C. elegans sensory neurons we examined, including the AWC olfactory neurons, the ASJ and ASK gustatory neurons, and the ASH and ADL nociceptors, respond to a rise in CO2 with a rise in Ca2+. In contrast, glial sheath cells harboring the sensory endings of C. elegans’ major chemosensory neurons exhibit strong and sustained decreases in Ca2+ in response to high CO2. Some of these CO2 responses appear to be cell intrinsic. Worms therefore may couple detection of CO2 to that of other cues at the earliest stages of sensory processing. We show that C. elegans persistently suppresses oviposition at high CO2. Hermaphrodite-specific neurons (HSNs), the executive neurons driving egg-laying, are tonically inhibited when CO2 is elevated. CO2 modulates the egg-laying system partly through the AWC olfactory neurons: High CO2 tonically activates AWC by a cGMP-dependent mechanism, and AWC output inhibits the HSNs. Our work shows that CO2 is a more complex sensory cue for C. elegans than previously thought, both in terms of behavior and neural circuitry. PMID:26100886

  9. Brain Activity in Fairness Consideration during Asset Distribution: Does the Initial Ownership Play a Role?

    Science.gov (United States)

    Wu, Yin; Hu, Jie; van Dijk, Eric; Leliveld, Marijke C.; Zhou, Xiaolin

    2012-01-01

    Previous behavioral studies have shown that initial ownership influences individuals’ fairness consideration and other-regarding behavior. However, it is not entirely clear whether initial ownership influences the brain activity when a recipient evaluates the fairness of asset distribution. In this study, we randomly assigned the bargaining property (monetary reward) to either the allocator or the recipient in the ultimatum game and let participants of the study, acting as recipients, receive either disadvantageous unequal, equal, or advantageous unequal offers from allocators while the event-related potentials (ERPs) were recorded. Behavioral results showed that participants were more likely to reject disadvantageous unequal and equal offers when they initially owned the property as compared to when they did not. The two types of unequal offers evoked more negative going ERPs (the MFN) than the equal offers in an early time window and the differences were not modulated by the initial ownership. In a late time window, however, the P300 responses to division schemes were affected not only by the type of unequal offers but also by whom the property was initially assigned to. These findings suggest that while the MFN may function as a general mechanism that evaluates whether the offer is consistent or inconsistent with the equity rule, the P300 is sensitive to top-down controlled processes, into which factors related to the allocation of attentional resources, including initial ownership and personal interests, come to play. PMID:22761850

  10. Metabolic dysfunction in the brain: implications of astrocyte activation

    Directory of Open Access Journals (Sweden)

    Sonia Luz Albarracin

    2015-02-01

    Full Text Available Astrocytes are the most abundant cells in the central nervous system (CNS. They participate in different processes such as maintaining the blood–brain barrier and ion homeostasis, uptake and turnover of neurotransmitters, and formation of synapses. In addition, astrocytes also respond to brain insults to prevent the damage. For instance, astrocyte activation plays a central role in the cellular response to brain insults like trauma, infections, stroke, tumorigenesis, and neurodegeneration. However, chronic astrocyte activation can also interfere with normal brain function. Neurodegenerative diseases like Alzheimer’s, Parkinson and amyotrophic lateral sclerosis are characterized by an inflammatory response that is considered the main cause of damage in these CNS disorders. This response is mediated by activated glial cells, which overexpress cytokines like TNF-a, IL-1β, IL-6, and other different pro-inflammatory factors. These pro-inflammatory signalling cascades can cause neurotoxicity and cell-death by reducing the astrocyte capacity of releasing neurotrophic factors, therefore decreasing their repair capability. Astrocyte activation is a dynamic process and its regulation is critical for maintaining an optimal neurological function that avoids the deleterious effects in neuronal survival. However, cellular and functional changes during astrocyte activation can be regulated in a context-specific manner by inter- and intracellular signalling molecules, for example increases in ammonium, glutamate, reactive oxygen species, and nitric oxide favoured astrocyte activation. In this review, we will discuss the state of the art of the metabolic changes that can lead to astrocyte activation and the possible therapeutic approaches to regulate these metabolic changes in astrocytes and their impact in neurons.

  11. Somatic Activation of AKT3 Causes Hemispheric Developmental Brain Malformations

    Science.gov (United States)

    Poduri, Annapurna; Evrony, Gilad D.; Cai, Xuyu; Elhosary, Princess Christina; Beroukhim, Rameen; Lehtinen, Maria K.; Hills, L. Benjamin; Heinzen, Erin L.; Hill, Anthony; Hill, R. Sean; Barry, Brenda J.; Bourgeois, Blaise F.D.; Riviello, James J.; Barkovich, A. James; Black, Peter M.; Ligon, Keith L.; Walsh, Christopher A.

    2012-01-01

    Summary Hemimegalencephaly (HMG) is a developmental brain disorder characterized by an enlarged, malformed cerebral hemisphere, typically causing epilepsy that requires surgical resection. We studied resected HMG tissue to test whether the condition might reflect somatic mutations affecting genes critical to brain development. We found that 2/8 HMG samples showed trisomy of chromosome 1q, encompassing many genes, including AKT3, which is known to regulate brain size. A third case showed a known activating mutation in AKT3 (c.49G→A, creating p.E17K) that was not present in the patient’s blood cells. Remarkably, the E17K mutation in AKT3 is exactly paralogous to E17K mutations in AKT1 and AKT2 recently discovered in somatic overgrowth syndromes. We show that AKT3 is the most abundant AKT paralogue in brain during neurogenesis and that phosphorylated AKT is abundant in cortical progenitor cells. Our data suggest that somatic mutations limited to brain could represent an important cause of complex neurogenetic disease. PMID:22500628

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

    Science.gov (United States)

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

    2017-01-01

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

  13. Nucleus accumbens deep brain stimulation results in insula and prefrontal activation: a large animal FMRI study.

    Directory of Open Access Journals (Sweden)

    Emily J Knight

    Full Text Available Deep Brain Stimulation (DBS of the nucleus accumbens (NAc has previously been investigated clinically for the treatment of several psychiatric conditions, including obsessive-compulsive disorder and treatment resistant depression. However, the mechanism underlying the therapeutic benefit of DBS, including the brain areas that are activated, remains largely unknown. Here, we utilized 3.0 T functional Magnetic Resonance Imaging (fMRI changes in Blood Oxygenation Level-Dependent (BOLD signal to test the hypothesis that NAc/internal capsule DBS results in global neural network activation in a large animal (porcine modelAnimals (n = 10 were implanted in the NAc/internal capsule with DBS electrodes and received stimulation (1, 3, and 5 V, 130 Hz, and pulse widths of 100 and 500 µsec. BOLD signal changes were evaluated using a gradient echo-echo planar imaging (GRE-EPI sequence in 3.0 T MRI. We used a normalized functional activation map for group analysis and applied general linear modeling across subjects (FDR<0.001. The anatomical location of the implanted DBS lead was confirmed with a CT scanWe observed stimulation-evoked activation in the ipsilateral prefrontal cortex, insula, cingulate and bilateral parahippocampal region along with decrease in BOLD signal in the ipsilateral dorsal region of the thalamus. Furthermore, as the stimulation voltage increased from 3 V to 5 V, the region of BOLD signal modulation increased in insula, thalamus, and parahippocampal cortex and decreased in the cingulate and prefrontal cortex. We also demonstrated that right and left NAc/internal capsule stimulation modulates identical areas ipsilateral to the side of the stimulationOur results suggest that NAc/internal capsule DBS results in modulation of psychiatrically important brain areas notably the prefrontal cortex, cingulate, and insular cortex, which may underlie the therapeutic effect of NAc DBS in psychiatric disorders. Finally, our fMRI setup in the large

  14. Estrogen modulation of the ethanol-evoked myocardial oxidative stress and dysfunction via DAPK3/Akt/ERK activation in male rats

    Energy Technology Data Exchange (ETDEWEB)

    El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Abdel-Rahman, Abdel A., E-mail: abdelrahmana@ecu.edu

    2015-09-15

    Evidence suggests that male rats are protected against the hypotensive and myocardial depressant effects of ethanol compared with females. We investigated whether E{sub 2} modifies the myocardial and oxidative effects of ethanol in male rats. Conscious male rats received ethanol (0.5, 1 or 1.5 g/kg i.v.) 30-min after E{sub 2} (1 μg/kg i.v.) or its vehicle (saline), and hearts were collected at the conclusion of hemodynamic measurements for ex vivo molecular studies. Ethanol had no effect in vehicle-treated rats, but it caused dose-related reductions in LV developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of rise in LV pressure (dP/dt{sub max}) and systolic (SBP) and diastolic (DBP) blood pressures in E{sub 2}-pretreated rats. These effects were associated with elevated (i) indices of reactive oxygen species (ROS), (ii) malondialdehyde (MDA) protein adducts, and (iii) phosphorylated death-associated protein kinase-3 (DAPK3), Akt, and extracellular signal-regulated kinases (ERK1/2). Enhanced myocardial anti-oxidant enzymes (heme oxygenase-1, catalase and aldehyde dehydrogenase 2) activities were also demonstrated. In conclusion, E{sub 2} promotes ethanol-evoked myocardial oxidative stress and dysfunction in male rats. The present findings highlight the risk of developing myocardial dysfunction in men who consume alcohol while receiving E{sub 2} for specific medical conditions. - Highlights: • Ethanol lowers blood pressure and causes LV dysfunction in E{sub 2}-treated rats. • E{sub 2}/ethanol aggravates cardiac oxidative state via of DAPK3/Akt/ERK activation. • E{sub 2}/ethanol causes a feedback increase in cardiac HO-1, catalase and ALDH2. • Alcohol might increase risk of myocardial dysfunction in men treated with E{sub 2}.

  15. Predicting human brain activity associated with the meanings of nouns.

    Science.gov (United States)

    Mitchell, Tom M; Shinkareva, Svetlana V; Carlson, Andrew; Chang, Kai-Min; Malave, Vicente L; Mason, Robert A; Just, Marcel Adam

    2008-05-30

    The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a computational model that predicts the functional magnetic resonance imaging (fMRI) neural activation associated with words for which fMRI data are not yet available. This model is trained with a combination of data from a trillion-word text corpus and observed fMRI data associated with viewing several dozen concrete nouns. Once trained, the model predicts fMRI activation for thousands of other concrete nouns in the text corpus, with highly significant accuracies over the 60 nouns for which we currently have fMRI data.

  16. Experience modulates motor imagery-based brain activity.

    Science.gov (United States)

    Kraeutner, Sarah N; McWhinney, Sean R; Solomon, Jack P; Dithurbide, Lori; Boe, Shaun G

    2018-03-07

    Whether or not brain activation during motor imagery (MI), the mental rehearsal of movement, is modulated by experience (i.e. skilled performance, achieved through long-term practice) remains unclear. Specifically, MI is generally associated with diffuse activation patterns that closely resemble novice physical performance, which may be attributable to a lack of experience with the task being imagined vs. being a distinguishing feature of MI. We sought to examine how experience modulates brain activity driven via MI, implementing a within- and between-group design to manipulate experience across tasks as well as expertise of the participants. Two groups of 'experts' (basketball/volleyball athletes) and 'novices' (recreational controls) underwent magnetoencephalography (MEG) while performing MI of four multi-articular tasks, selected to ensure that the degree of experience that participants had with each task varied. Source-level analysis was applied to MEG data and linear mixed effects modelling was conducted to examine task-related changes in activity. Within- and between-group comparisons were completed post hoc and difference maps were plotted. Brain activation patterns observed during MI of tasks for which participants had a low degree of experience were more widespread and bilateral (i.e. within-groups), with limited differences observed during MI of tasks for which participants had similar experience (i.e. between-groups). Thus, we show that brain activity during MI is modulated by experience; specifically, that novice performance is associated with the additional recruitment of regions across both hemispheres. Future investigations of the neural correlates of MI should consider prior experience when selecting the task to be performed. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  17. Rapid Modulation of Aromatase Activity in the Vertebrate Brain

    Directory of Open Access Journals (Sweden)

    Thierry D. Charlier

    2013-01-01

    Full Text Available Numerous steroid hormones, including 17β-estradiol (E2, activate rapid and transient cellular, physiological, and behavioral changes in addition to their well-described genomic effects. Aromatase is the key-limiting enzyme in the production of estrogens, and the rapid modulation of this enzymatic activity could produce rapid changes in local E2 concentrations. The mechanisms that might mediate such rapid enzymatic changes are not fully understood but are currently under intense scrutiny. Recent studies in our laboratory indicate that brain aromatase activity is rapidly inhibited by an increase in intracellular calcium concentration resulting from potassium-induced depolarization or from the activation of glutamatergic receptors. Phosphorylating conditions also reduce aromatase activity within minutes, and this inhibition is blocked by the addition of multiple protein kinase inhibitors. This rapid modulation of aromatase activity by phosphorylating conditions is a general mechanism observed in different cell types and tissues derived from a variety of species, including human aromatase expressed in various cell lines. Phosphorylation processes affect aromatase itself and do not involve changes in aromatase protein concentration. The control of aromatase activity by multiple kinases suggests that several amino acids must be concomitantly phosphorylated to modify enzymatic activity but site-directed mutagenesis of several amino acids alone or in combination has not to date revealed the identity of the targeted residue(s. Altogether, the phosphorylation processes affecting aromatase activity provide a new general mechanism by which the concentration of estrogens can be rapidly altered in the brain.

  18. Effects of Long-Term Acupuncture Treatment on Resting-State Brain Activity in Migraine Patients: A Randomized Controlled Trial on Active Acupoints and Inactive Acupoints

    Science.gov (United States)

    Zhao, Ling; Liu, Jixin; Zhang, Fuwen; Dong, Xilin; Peng, Yulin; Qin, Wei; Wu, Fumei; Li, Ying; Yuan, Kai; von Deneen, Karen M.; Gong, Qiyong; Tang, Zili; Liang, Fanrong

    2014-01-01

    Background Acupuncture has been commonly used for preventing migraine attacks and relieving pain during a migraine, although there is limited knowledge on the physiological mechanism behind this method. The objectives of this study were to compare the differences in brain activities evoked by active acupoints and inactive acupoints and to investigate the possible correlation between clinical variables and brain responses. Methods and Results A randomized controlled trial and resting-state functional magnetic resonance imaging (fMRI) were conducted. A total of eighty migraineurs without aura were enrolled to receive either active acupoint acupuncture or inactive acupoint acupuncture treatment for 8 weeks, and twenty patients in each group were randomly selected for the fMRI scan at the end of baseline and at the end of treatment. The neuroimaging data indicated that long-term active acupoint therapy elicited a more extensive and remarkable cerebral response compared with acupuncture at inactive acupoints. Most of the regions were involved in the pain matrix, lateral pain system, medial pain system, default mode network, and cognitive components of pain processing. Correlation analysis showed that the decrease in the visual analogue scale (VAS) was significantly related to the increased average Regional homogeneity (ReHo) values in the anterior cingulate cortex in the two groups. Moreover, the decrease in the VAS was associated with increased average ReHo values in the insula which could be detected in the active acupoint group. Conclusions Long-term active acupoint therapy and inactive acupoint therapy have different brain activities. We postulate that acupuncture at the active acupoint might have the potential effect of regulating some disease-affected key regions and the pain circuitry for migraine, and promote establishing psychophysical pain homeostasis. Trial Registration Chinese Clinical Trial Registry ChiCTR-TRC-13003635 PMID:24915066

  19. 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.

  20. Contributions of Glycogen to Astrocytic Energetics during Brain Activation

    Science.gov (United States)

    Dienel, Gerald A.; Cruz, Nancy F.

    2014-01-01

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

  1. 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

  2. The influence of active hexose correlated compound (AHCC) on cisplatin-evoked chemotherapeutic and side effects in tumor-bearing mice

    International Nuclear Information System (INIS)

    Hirose, Aya; Sato, Eri; Fujii, Hajime; Sun Buxiang; Nishioka, Hiroshi; Aruoma, Okezie I.

    2007-01-01

    Cisplatin (cis-diaminedichloroplatinum (II) or CDDP) (a widely used platinum-containing anticancer drug) is nephrotoxic and has a low percentage of tolerance in patients during chemotherapy. The active hexose correlated compound (AHCC) is an extract of Basidiomycotina marketed as a supplement for cancer patients due to its nutrients and fibre content and its ability to strengthen and optimize the capacity of the immune system. The possibility that AHCC could reduce the side effects of cisplatin was assessed in the tumor-bearing BALB/cA mice on the basis of the ability to ameliorate the cisplatin-induced body weight loss, anorexia, nephrotoxicity and hematopoietic toxicity. Although cisplatin (8 mg/kg body weight) reduced the size and weight of the solid tumors, supplementation with AHCC significantly enhanced cisplatin-induced antitumor effect in both the size (p < 0.05) and weight (p < 0.05). Food intake in the cisplatin-treated mice were decreased following commencement of treatment and this remained low compared with the cisplatin-untreated group (control) throughout the experiment period. Supplementation with AHCC increased the food intake in the cisplatin-treated mice. The blood urea nitrogen and serum creatinine concentrations, and the ratio of blood urea nitrogen to serum creatinine were significantly increased in the cisplatin alone treated group compared to the control group. Their increased levels were mitigated by supplementation with AHCC (100 mg/kg body weight) in the cisplatin-treated group. AHCC was also able to modulate the suppression of bone marrow due to cisplatin and the improvement was statistically significant. The histopathological examination of the kidney revealed the presence of cisplatin-induced damage and this was modulated by AHCC treatment. The potential for AHCC to ameliorate the cisplatin-evoked toxicity as well as the chemotherapeutic effect could have beneficial economic implications for patients undergoing chemotherapy with

  3. The influence of active hexose correlated compound (AHCC) on cisplatin-evoked chemotherapeutic and side effects in tumor-bearing mice.

    Science.gov (United States)

    Hirose, Aya; Sato, Eri; Fujii, Hajime; Sun, Buxiang; Nishioka, Hiroshi; Aruoma, Okezie I

    2007-07-15

    Cisplatin (cis-diaminedichloroplatinum (II) or CDDP) (a widely used platinum-containing anticancer drug) is nephrotoxic and has a low percentage of tolerance in patients during chemotherapy. The active hexose correlated compound (AHCC) is an extract of Basidiomycotina marketed as a supplement for cancer patients due to its nutrients and fibre content and its ability to strengthen and optimize the capacity of the immune system. The possibility that AHCC could reduce the side effects of cisplatin was assessed in the tumor-bearing BALB/cA mice on the basis of the ability to ameliorate the cisplatin-induced body weight loss, anorexia, nephrotoxicity and hematopoietic toxicity. Although cisplatin (8 mg/kg body weight) reduced the size and weight of the solid tumors, supplementation with AHCC significantly enhanced cisplatin-induced antitumor effect in both the size (pcisplatin-treated mice were decreased following commencement of treatment and this remained low compared with the cisplatin-untreated group (control) throughout the experiment period. Supplementation with AHCC increased the food intake in the cisplatin-treated mice. The blood urea nitrogen and serum creatinine concentrations, and the ratio of blood urea nitrogen to serum creatinine were significantly increased in the cisplatin alone treated group compared to the control group. Their increased levels were mitigated by supplementation with AHCC (100 mg/kg body weight) in the cisplatin-treated group. AHCC was also able to modulate the suppression of bone marrow due to cisplatin and the improvement was statistically significant. The histopathological examination of the kidney revealed the presence of cisplatin-induced damage and this was modulated by AHCC treatment. The potential for AHCC to ameliorate the cisplatin-evoked toxicity as well as the chemotherapeutic effect could have beneficial economic implications for patients undergoing chemotherapy with cisplatin.

  4. [Correlation of brain electrical activity and motivation in healthy people].

    Science.gov (United States)

    Bogovin, L V; Nakhamchen, D L; Kolosov, V P; Perel'man, Iu M

    2014-01-01

    Motivation dominates in the structure of the personality and is one of the basic notions which explains the dynamics of the behavior. The literature has little data about neurophysiology of motivation. The aim of the research was to study the correlation between the motivational sphere and electrical activity of the brain at the influence of different provocations. 24 healthy people at the age of 26-36 years were examined. The results of motivation tests turned out to be uniform (the motivation to success was of a moderate or high level, there were mean values of readiness to risk and low motivation to achievement and approval). Multiple correlations between different types of motivation and electrical activity of the brain at rest, at hyperventilation with room temperature air and at isocapnic cold air hyperventilation were revealed.

  5. Human brain activity with near-infrared spectroscopy

    Science.gov (United States)

    Luo, Qingming; Chance, Britton

    1999-09-01

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

  6. 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.

  7. Altered brain activation during response inhibition in obstructive sleep apnea

    OpenAIRE

    Ayalon, Liat; Ancoli-Israel, Sonia; Drummond, Sean PA

    2009-01-01

    This study examined response inhibition during a Go-NoGo task in individuals with obstructive sleep apnea (OSA). Fourteen OSA patients and 14 controls were studied with functional magnetic resonance imaging (FMRI). Compared to Controls, the OSA group showed more false positives (error of commission) during the NoGo trials with decreased brain activation in the left postcentral gyrus, cingulate gyrus, and inferior parietal lobe, as well as right insula and putamen. This is consistent with prev...

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

    Science.gov (United States)

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

    2015-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Hércules Rezende Freitas

    2017-11-01

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

  10. Using human brain activity to guide machine learning.

    Science.gov (United States)

    Fong, Ruth C; Scheirer, Walter J; Cox, David D

    2018-03-29

    Machine learning is a field of computer science that builds algorithms that learn. In many cases, machine learning algorithms are used to recreate a human ability like adding a caption to a photo, driving a car, or playing a game. While the human brain has long served as a source of inspiration for machine learning, little effort has been made to directly use data collected from working brains as a guide for machine learning algorithms. Here we demonstrate a new paradigm of "neurally-weighted" machine learning, which takes fMRI measurements of human brain activity from subjects viewing images, and infuses these data into the training process of an object recognition learning algorithm to make it more consistent with the human brain. After training, these neurally-weighted classifiers are able to classify images without requiring any additional neural data. We show that our neural-weighting approach can lead to large performance gains when used with traditional machine vision features, as well as to significant improvements with already high-performing convolutional neural network features. The effectiveness of this approach points to a path forward for a new class of hybrid machine learning algorithms which take both inspiration and direct constraints from neuronal data.

  11. Consciousness as a global property of brain dynamic activity.

    Science.gov (United States)

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

    2017-12-01

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

  12. Consciousness as a global property of brain dynamic activity

    Science.gov (United States)

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

    2017-12-01

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

  13. International Evoked Potentials Symposium

    CERN Document Server

    1980-01-01

    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  14. Auditory evoked responses upon awakening from sleep in human subjects.

    Science.gov (United States)

    Ferrara, M; De Gennaro, L; Ferlazzo, F; Curcio, G; Barattucci, M; Bertini, M

    2001-09-14

    The hypothesis that a state of hypoarousal upon awakening should lead to a decrease in amplitude and an increase in latency of the N1-P2 components of the Auditory Evoked Potentials (AEPs) as compared to presleep wakefulness levels, was evaluated after two nocturnal awakenings and after the final morning awakening from a 7.5-h night of sleep. The amplitude of the N1-P2 complex was reduced upon awakening as compared to presleep wakefulness levels, but only following the first nocturnal awakening, scheduled after the first 2 h of sleep. This result is interpreted as indicating a link between slow wave sleep amount, mainly present during the first part of the night, and lowered levels of brain activation upon awakening. The reaction times, recorded concomitantly to AEPs, were more sensitive to the negative effects of sleep inertia.

  15. Is the auditory evoked P2 response a biomarker of learning?

    Directory of Open Access Journals (Sweden)

    Kelly eTremblay

    2014-02-01

    Full Text Available Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography and magnetoencephalography have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP, as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What’s more, these effects were retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN wave 600-900 ms post-stimulus onset, post-training, exclusively for the group that learned to identify the pre

  16. Retrieving Binary Answers Using Whole-Brain Activity Pattern Classification.

    Science.gov (United States)

    Nawa, Norberto E; Ando, Hiroshi

    2015-01-01

    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.

  17. 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

  18. Guiding transcranial brain stimulation by EEG/MEG to interact with ongoing brain activity and associated functions

    DEFF Research Database (Denmark)

    Thut, Gregor; Bergmann, Til Ole; Fröhlich, Flavio

    2017-01-01

    Non-invasive transcranial brain stimulation (NTBS) techniques have a wide range of applications but also suffer from a number of limitations mainly related to poor specificity of intervention and variable effect size. These limitations motivated recent efforts to focus on the temporal dimension...... of NTBS with respect to the ongoing brain activity. Temporal patterns of ongoing neuronal activity, in particular brain oscillations and their fluctuations, can be traced with electro- or magnetoencephalography (EEG/MEG), to guide the timing as well as the stimulation settings of NTBS. These novel, online...... and offline EEG/MEG-guided NTBS-approaches are tailored to specifically interact with the underlying brain activity. Online EEG/MEG has been used to guide the timing of NTBS (i.e., when to stimulate): by taking into account instantaneous phase or power of oscillatory brain activity, NTBS can be aligned...

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

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2017-07-01

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

  1. 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.

  2. Activation of dominant hemisphere association cortex during naming as a function of cognitive performance in mild traumatic brain injury: Insights into mechanisms of lexical access

    Directory of Open Access Journals (Sweden)

    Mihai Popescu

    2017-01-01

    Full Text Available Patients with a history of mild traumatic brain injury (mTBI and objective cognitive deficits frequently experience word finding difficulties in normal conversation. We sought to improve our understanding of this phenomenon by determining if the scores on standardized cognitive testing are correlated with measures of brain activity evoked in a word retrieval task (confrontational picture naming. The study participants (n = 57 were military service members with a history of mTBI. The General Memory Index (GMI determined after administration of the Rivermead Behavioral Memory Test, Third Edition, was used to assign subjects to three groups: low cognitive performance (Group 1: GMI ≤ 87, n = 18, intermediate cognitive performance (Group 2: 88 ≤ GMI ≤ 99, n = 18, and high cognitive performance (Group 3: GMI ≥ 100, n = 21. Magnetoencephalography data were recorded while participants named eighty pictures of common objects. Group differences in evoked cortical activity were observed relatively early (within 200 ms from picture onset over a distributed network of left hemisphere cortical regions including the fusiform gyrus, the entorhinal and parahippocampal cortex, the supramarginal gyrus and posterior part of the superior temporal gyrus, and the inferior frontal and rostral middle frontal gyri. Differences were also present in bilateral cingulate cortex and paracentral lobule, and in the right fusiform gyrus. All differences reflected a lower amplitude of the evoked responses for Group 1 relative to Groups 2 and 3. These findings may indicate weak afferent inputs to and within an extended cortical network including association cortex of the dominant hemisphere in patients with low cognitive performance. The association between word finding difficulties and low cognitive performance may therefore be the result of a diffuse pathophysiological process affecting distributed neuronal networks serving a wide range of cognitive

  3. Recognition of stimulus-evoked neuronal optical response by identifying chaos levels of near-infrared spectroscopy time series.

    Science.gov (United States)

    Hu, Xiao-Su; Hong, Keum-Shik; Ge, Shuzhi Sam

    2011-10-24

    Near-infrared spectroscopy (NIRS) can detect two different kinds of signals from the human brain: the hemodynamic response (slow) and the neuronal response (fast). This paper explores a nonlinear aspect in the tactile-stimulus-evoked neuronal optical response over a NIRS time series (light intensity variation). The existence of the fast optical responses (FORs) over the time series recorded in stimulus sessions is confirmed by event-related averaging. The chaos levels of the NIRS time series recorded both in stimulus and in rest sessions are then identified according to the estimated largest Lyapunov exponent. The obtained results ascertain that stimulus-evoked neuronal optical responses can be detected in the somatosensory cortex using continuous-wave NIRS equipment. Further, the results strongly suggest that the chaos level can be used to recognize the FORs in NIRS time series and, thereby, the state of the pertinent brain activity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Resting-State Brain Activity in Adult Males Who Stutter

    Science.gov (United States)

    Zhu, Chaozhe; Wang, Liang; Yan, Qian; Lin, Chunlan; Yu, Chunshui

    2012-01-01

    Although developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI), few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF), region of interest (ROI)-based functional connectivity (FC) and independent component analysis (ICA)-based FC. Forty-four adult males with developmental stuttering and 46 age-matched fluent male controls were scanned using resting-state fMRI. ALFF, ROI-based FCs and ICA-based FCs were compared between male stuttering subjects and fluent controls in a voxel-wise manner. Compared with fluent controls, stuttering subjects showed increased ALFF in left brain areas related to speech motor and auditory functions and bilateral prefrontal cortices related to cognitive control. However, stuttering subjects showed decreased ALFF in the left posterior language reception area and bilateral non-speech motor areas. ROI-based FC analysis revealed decreased FC between the posterior language area involved in the perception and decoding of sensory information and anterior brain area involved in the initiation of speech motor function, as well as increased FC within anterior or posterior speech- and language-associated areas and between the prefrontal areas and default-mode network (DMN) in stuttering subjects. ICA showed that stuttering subjects had decreased FC in the DMN and increased FC in the sensorimotor network. Our findings support the concept that stuttering subjects have deficits in multiple functional systems (motor, language, auditory and DMN) and in the connections between them. PMID:22276215

  5. Resting-state brain activity in adult males who stutter.

    Directory of Open Access Journals (Sweden)

    Yun Xuan

    Full Text Available Although developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI, few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF, region of interest (ROI-based functional connectivity (FC and independent component analysis (ICA-based FC. Forty-four adult males with developmental stuttering and 46 age-matched fluent male controls were scanned using resting-state fMRI. ALFF, ROI-based FCs and ICA-based FCs were compared between male stuttering subjects and fluent controls in a voxel-wise manner. Compared with fluent controls, stuttering subjects showed increased ALFF in left brain areas related to speech motor and auditory functions and bilateral prefrontal cortices related to cognitive control. However, stuttering subjects showed decreased ALFF in the left posterior language reception area and bilateral non-speech motor areas. ROI-based FC analysis revealed decreased FC between the posterior language area involved in the perception and decoding of sensory information and anterior brain area involved in the initiation of speech motor function, as well as increased FC within anterior or posterior speech- and language-associated areas and between the prefrontal areas and default-mode network (DMN in stuttering subjects. ICA showed that stuttering subjects had decreased FC in the DMN and increased FC in the sensorimotor network. Our findings support the concept that stuttering subjects have deficits in multiple functional systems (motor, language, auditory and DMN and in the connections between them.

  6. Amplitude-modulated stimuli reveal auditory-visual interactions in brain activity and brain connectivity

    Directory of Open Access Journals (Sweden)

    Mark eLaing

    2015-10-01

    Full Text Available The temporal congruence between auditory and visual signals coming from the same source can be a powerful means by which the brain integrates information from different senses. To investigate how the brain uses temporal information to integrate auditory and visual information from continuous yet unfamiliar stimuli, we use amplitude-modulated tones and size-modulated shapes with which we could manipulate the temporal congruence between the sensory signals. These signals were independently modulated at a slow or a fast rate. Participants were presented with auditory-only, visual-only or auditory-visual (AV trials in the scanner. On AV trials, the auditory and visual signal could have the same (AV congruent or different modulation rates (AV incongruent. Using psychophysiological interaction analyses, we found that auditory regions showed increased functional connectivity predominantly with frontal regions for AV incongruent relative to AV congruent stimuli. We further found that superior temporal regions, shown previously to integrate auditory and visual signals, showed increased connectivity with frontal and parietal regions for the same contrast. Our findings provide evidence that both activity in a network of brain regions and their connectivity are important for auditory-visual integration, and help to bridge the gap between transient and familiar AV stimuli used in previous studies.

  7. Amplitude-modulated stimuli reveal auditory-visual interactions in brain activity and brain connectivity.

    Science.gov (United States)

    Laing, Mark; Rees, Adrian; Vuong, Quoc C

    2015-01-01

    The temporal congruence between auditory and visual signals coming from the same source can be a powerful means by which the brain integrates information from different senses. To investigate how the brain uses temporal information to integrate auditory and visual information from continuous yet unfamiliar stimuli, we used amplitude-modulated tones and size-modulated shapes with which we could manipulate the temporal congruence between the sensory signals. These signals were independently modulated at a slow or a fast rate. Participants were presented with auditory-only, visual-only, or auditory-visual (AV) trials in the fMRI scanner. On AV trials, the auditory and visual signal could have the same (AV congruent) or different modulation rates (AV incongruent). Using psychophysiological interaction analyses, we found that auditory regions showed increased functional connectivity predominantly with frontal regions for AV incongruent relative to AV congruent stimuli. We further found that superior temporal regions, shown previously to integrate auditory and visual signals, showed increased connectivity with frontal and parietal regions for the same contrast. Our findings provide evidence that both activity in a network of brain regions and their connectivity are important for AV integration, and help to bridge the gap between transient and familiar AV stimuli used in previous studies.

  8. Echoic memory of a single pure tone indexed by change-related brain activity

    Directory of Open Access Journals (Sweden)

    Motomura Eishi

    2010-10-01

    Full Text Available Abstract Background The rapid detection of sensory change is important to survival. The process should relate closely to memory since it requires that the brain separate a new stimulus from an ongoing background or past event. Given that sensory memory monitors current sensory status and works to pick-up changes in real-time, any change detected by this system should evoke a change-related cortical response. To test this hypothesis, we examined whether the single presentation of a sound is enough to elicit a change-related cortical response, and therefore, shape a memory trace enough to separate a subsequent stimulus. Results Under a paradigm where two pure sounds 300 ms in duration and 800 or 840 Hz in frequency were presented in a specific order at an even probability, cortical responses to each sound were measured with magnetoencephalograms. Sounds were grouped to five events regardless of their frequency, 1D, 2D, and 3D (a sound preceded by one, two, or three different sounds, and 1S and 2S (a sound preceded by one or two same sounds. Whereas activation in the planum temporale did not differ among events, activation in the superior temporal gyrus (STG was clearly greater for the different events (1D, 2D, 3D than the same event (1S and 2S. Conclusions One presentation of a sound is enough to shape a memory trace for comparison with a subsequent physically different sound and elicits change-related cortical responses in the STG. The STG works as a real-time sensory gate open to a new event.

  9. Echoic memory of a single pure tone indexed by change-related brain activity.

    Science.gov (United States)

    Inui, Koji; Urakawa, Tomokazu; Yamashiro, Koya; Otsuru, Naofumi; Takeshima, Yasuyuki; Nishihara, Makoto; Motomura, Eishi; Kida, Tetsuo; Kakigi, Ryusuke

    2010-10-20

    The rapid detection of sensory change is important to survival. The process should relate closely to memory since it requires that the brain separate a new stimulus from an ongoing background or past event. Given that sensory memory monitors current sensory status and works to pick-up changes in real-time, any change detected by this system should evoke a change-related cortical response. To test this hypothesis, we examined whether the single presentation of a sound is enough to elicit a change-related cortical response, and therefore, shape a memory trace enough to separate a subsequent stimulus. Under a paradigm where two pure sounds 300 ms in duration and 800 or 840 Hz in frequency were presented in a specific order at an even probability, cortical responses to each sound were measured with magnetoencephalograms. Sounds were grouped to five events regardless of their frequency, 1D, 2D, and 3D (a sound preceded by one, two, or three different sounds), and 1S and 2S (a sound preceded by one or two same sounds). Whereas activation in the planum temporale did not differ among events, activation in the superior temporal gyrus (STG) was clearly greater for the different events (1D, 2D, 3D) than the same event (1S and 2S). One presentation of a sound is enough to shape a memory trace for comparison with a subsequent physically different sound and elicits change-related cortical responses in the STG. The STG works as a real-time sensory gate open to a new event.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  12. 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.

  13. Brain activation in high-functioning older adults and falls

    Science.gov (United States)

    Wang, Cuiling; Ayers, Emmeline; Izzetoglu, Meltem; Holtzer, Roee

    2017-01-01

    Objective: To determine whether brain activity over the prefrontal cortex measured in real time during walking predicts falls in high-functioning older adults. Method: We examined166 older persons (mean age 75 years, 51% women) enrolled in a prospective aging study. High-functioning status defined as the absence of dementia or disability with normal gait diagnosed by study clinicians. The magnitude of task-related changes in oxygenated hemoglobin levels over the prefrontal cortex was measured with functional near-infrared spectroscopy during motor (walking at normal pace) and cognitive (reciting alternate letters of the alphabet) single tasks and a dual-task condition (walking while reciting alternate letters of the alphabet). Incident falls were prospectively assessed over a 50-month study period. Results: Over a mean follow-up of 33.9 ± 11.9 months, 116 falls occurred. Higher levels of prefrontal cortical activation during the dual-task walking condition predicted falls (hazard ratio adjusted for age, sex, education, medical illnesses and general mental status 1.32, 95% confidence interval 1.03–1.70). Neither behavioral outcomes (velocity or letter rate) on the dual task nor brain activation patterns on the single tasks (normal walk or talk alone) predicted falls in this high-functioning sample. The results remained robust after accounting for multiple confounders and for cognitive status, slow gait, previous falls, and frailty. Conclusions: Prefrontal brain activity levels while performing a cognitively demanding walking condition predicted falls in high-functioning seniors. These findings implicate neurobiological processes early in the pathogenesis of falls. PMID:27927937

  14. 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.

  15. Music evokes vivid autobiographical memories.

    Science.gov (United States)

    Belfi, Amy M; Karlan, Brett; Tranel, Daniel

    2016-08-01

    Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.

  16. Adjective metaphors evoke negative meanings.

    Directory of Open Access Journals (Sweden)

    Maki Sakamoto

    Full Text Available Previous metaphor studies have paid much attention to nominal metaphors and predicative metaphors, but little attention has been given to adjective metaphors. Although some studies have focused on adjective metaphors, they only examined differences in the acceptability of various types of adjective metaphors. This paper explores the cognitive effects evoked by adjective metaphors. Three psychological experiments revealed that (1 adjective metaphors, especially those modified by color adjectives, tend to evoke negative effect; (2 although the meanings of metaphors are basically affected by the meanings of their vehicles, when a vehicle has a neutral meaning, negative meanings are evoked most frequently for adjective metaphors compared to nominal and predicative metaphors; (3 negative meanings evoked by adjective metaphors are related to poeticness, and poetic metaphors evoke negative meanings more easily than less poetic metaphors. Our research sheds new light on studies of the use of metaphor, which is one of the most basic human cognitive abilities.

  17. Rapid and minimum invasive functional brain mapping by real-time visualization of high gamma activity during awake craniotomy.

    Science.gov (United States)

    Ogawa, Hiroshi; Kamada, Kyousuke; Kapeller, Christoph; Hiroshima, Satoru; Prueckl, Robert; Guger, Christoph

    2014-11-01

    Electrocortical stimulation (ECS) is the gold standard for functional brain mapping during an awake craniotomy. The critical issue is to set aside enough time to identify eloquent cortices by ECS. High gamma activity (HGA) ranging between 80 and 120 Hz on electrocorticogram is assumed to reflect localized cortical processing. In this report, we used real-time HGA mapping and functional neuronavigation integrated with functional magnetic resonance imaging (fMRI) for rapid and reliable identification of motor and language functions. Four patients with intra-axial tumors in their dominant hemisphere underwent preoperative fMRI and lesion resection with an awake craniotomy. All patients showed significant fMRI activation evoked by motor and language tasks. During the craniotomy, we recorded electrocorticogram activity by placing subdural grids directly on the exposed brain surface. Each patient performed motor and language tasks and demonstrated real-time HGA dynamics in hand motor areas and parts of the inferior frontal gyrus. Sensitivity and specificity of HGA mapping were 100% compared with ECS mapping in the frontal lobe, which suggested HGA mapping precisely indicated eloquent cortices. We found different HGA dynamics of language tasks in frontal and temporal regions. Specificities of the motor and language-fMRI did not reach 85%. The results of HGA mapping was mostly consistent with those of ECS mapping, although fMRI tended to overestimate functional areas. This novel technique enables rapid and accurate identification of motor and frontal language areas. Furthermore, real-time HGA mapping sheds light on underlying physiological mechanisms related to human brain functions. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. 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

  19. Method for assessing brain changes associated with gluteus maximus activation.

    Science.gov (United States)

    Fisher, Beth E; Lee, Ya-Yun; Pitsch, Erica A; Moore, Brian; Southam, Anna; Faw, Timothy D; Powers, Christopher M

    2013-04-01

    Reliability study. To determine the feasibility and reliability of using transcranial magnetic stimulation (TMS) to assess corticomotor excitability (CE) of the gluteus maximus. Sport-specific skill training targeting greater utilization of the gluteus maximus has been proposed as a method to reduce the incidence of noncontact knee injuries. The use of TMS to assess changes in CE may help to determine training-induced central mechanisms associated with gluteus maximus activation. Within- and between-day reliability was measured in 10 healthy adults. The CE was measured by stimulating the gluteus maximus ìhotspotî at 120% and 150% of motor threshold, while subjects performed a double-leg bridge. An intraclass correlation coefficient (model 2,1), standard error of measurement, and minimal detectable change were calculated to determine the within- and between-day reliability for the following TMS variables: peak-to-peak motor-evoked potential (MEP) amplitudes, cortical silent period, and MEP latency. It is feasible to measure the CE of the gluteus maximus with TMS. The intraclass correlation coefficients for all TMS outcome measures ranged from 0.73 to 0.97. The ranges of minimal detectable change, with respect to mean values for each TMS variable, were larger for MEP amplitude (304.7-585.4 µV) compared to those for cortical silent period duration (25.3-40.8 milliseconds) and MEP latency (1.1-2.1 milliseconds). The present study demonstrated a feasible method for using TMS to measure CE of the gluteus maximus. Small minimal detectable change values for the cortical silent period and MEP latency provide a reference for future studies.

  20. [Brain activity during different stages of the relaxation process].

    Science.gov (United States)

    gorev, A S; Kovaleva, A V; Panova, E N; Gorbacheva, A K

    2012-01-01

    A group of adults participated in experiment in which they were asked to reach relaxed state by using relaxation techniques (active relaxation) and to maintain this state without any technique (passive relaxation). Some changes of EEG-characteristics during relaxation were analyzed. This experiment includes four situations (different functional states): baselinel, active relaxation, passive relaxation, baseline2. EEG was recorded from 10 cortical leads: O1, O2, TPO (left and right), P3, P4, C3, C4, F3 and F4. A comparative EEG analysis was done for 10 frequency bands from 5 to 40 Hz. In each experimental situation we revealed general trends for EEG parameters and also some specific changes in EEG, which characterized brain organization during passive and active relaxed states.

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

    Science.gov (United States)

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

    2017-04-01

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

  2. Echoic memory of a single pure tone indexed by change-related brain activity

    OpenAIRE

    Inui, Koji; Urakawa, Tomokazu; Yamashiro, Koya; Otsuru, Naofumi; Takeshima, Yasuyuki; Nishihara, Makoto; Motomura, Eishi; Kida, Tetsuo; Kakigi, Ryusuke

    2010-01-01

    Abstract Background The rapid detection of sensory change is important to survival. The process should relate closely to memory since it requires that the brain separate a new stimulus from an ongoing background or past event. Given that sensory memory monitors current sensory status and works to pick-up changes in real-time, any change detected by this system should evoke a change-related cortical response. To test this hypothesis, we examined whether the single presentation of a sound is en...

  3. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation.

    Directory of Open Access Journals (Sweden)

    Katsuya Kobayashi

    Full Text Available Physiological high frequency activities (HFA are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections, or different terminal layers (layer IV vs. layer II/III affect its frequency, we, in the primary somatosensory cortex (SI, compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response and N80 (late response of somatosensory evoked potentials (HFA(SEP(N20 and HFA(SEP(N80 and compared those overriding N1 and N2 (first and second responses of cortico-cortical evoked potentials (HFA(CCEP(N1 and HFA(CCEP(N2. HFA(SEP(N20 showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1 had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1 and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

  4. Motor potentials evoked by paired cortical stimuli.

    Science.gov (United States)

    Inghilleri, M; Berardelli, A; Cruccu, G; Priori, A; Manfredi, M

    1990-01-01

    We recorded the motor evoked potentials (MEPs) from the abductor pollicis brevis muscle, after supramaximal electrical transcranial stimulation, and studied the effect of paired transcranial shocks with varying interstimulus time intervals, in 10 normal subjects, 4 patients with median nerve neuropathy and 2 patients with motoneurone disease. In relaxed muscles the amplitude of the MEP evoked by a single shock averaged 30% of the M wave. With intervals from 1 to 2.5 msec 2 shocks evoked one MEP far larger in size than the control MEP (70% of the M wave). With intervals of 10 msec and longer, the 2 shocks evoked 2 independent MEPs; the size of the MEP following the second shock (test) was inversely correlated with the size of the control MEP: the more the control MEP approached the size of the M wave, the smaller the test MEP. Single motor unit records showed that, in the normal subjects and patients with peripheral neuropathy, the same motor unit was activated either by the first or the second shock, whereas in the patients with motoneurone disease it fired twice. In active muscles, the control MEP averaged 70% of the M wave. With intervals of 10 msec and longer the test MEP was markedly suppressed; with 100 msec intervals it fully recovered. In relaxed muscles, by delivering a double shock at a 1.5 msec interval, thus evoking a large MEP, followed by a second double-shock, the test MEP was completely suppressed for a period of 20 msec; it began to recover at 50 msec intervals and fully recovered after 150 msec.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    Science.gov (United States)

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

    2011-01-01

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

  6. Brain activity and desire for internet video game play

    Science.gov (United States)

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

    2010-01-01

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

  7. The role of Magnetic Resonance Imaging and Visual Evoked ...

    African Journals Online (AJOL)

    Introduction: To report our experience in management of patients with optic neuritis. The effects of brain magnetic resonance imaging and visual evoked potential on management were investigated. Methods: This is a four years clinical trial that included patients presenting with first attack of optic neuritis older than 16 years ...

  8. Expression and activity of the urokinase plasminogen activator system in canine primary brain tumors

    Directory of Open Access Journals (Sweden)

    Rossmeisl JH

    2017-04-01

    Full Text Available John H Rossmeisl,1–3 Kelli Hall-Manning,4 John L Robertson,1,3,5 Jamie N King,1,2 Rafael V Davalos,3,5 Waldemar Debinski,3 Subbiah Elankumaran6,† 1Veterinary and Comparative Neuro-Oncology Laboratory, 2Department of Small Animal Clinical Sciences, 3The Brain Tumor Center of Excellence, Wake Forest Baptist Medical Center Comprehensive Cancer Center, Winston-Salem, NC, 4Virginia Tech Animal Laboratory Services, Virginia-Maryland College of Veterinary Medicine, 5Department of Biomedical Engineering and Mechanics, Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Virginia Tech, 6Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, USA†The authors regret to advise of the passing of Dr Subbiah Elankumaran prior to publicationBackground: The expression of the urokinase plasminogen activator receptor (uPAR, a glycosylphosphatidylinositol-anchored protein family member, and the activity of its ligand, urokinase-type plasminogen activator (uPA, have been associated with the invasive and metastatic potentials of a variety of human brain tumors through their regulation of extracellular matrix degradation. Domesticated dogs develop naturally occurring brain tumors that share many clinical, phenotypic, molecular, and genetic features with their human counterparts, which has prompted the use of the dogs with spontaneous brain tumors as models to expedite the translation of novel brain tumor therapeutics to humans. There is currently little known regarding the role of the uPA system in canine brain tumorigenesis. The objective of this study was to characterize the expression of uPAR and the activity of uPA in canine brain tumors as justification for the development of uPAR-targeted brain tumor therapeutics in dogs.Methods: We investigated the expression of uPAR in 37 primary canine brain tumors using immunohistochemistry, Western blotting, real

  9. Does the reading of different orthographies produce distinct brain activity patterns? An ERP study.

    Directory of Open Access Journals (Sweden)

    Irit Bar-Kochva

    Full Text Available Orthographies vary in the degree of transparency of spelling-sound correspondence. These range from shallow orthographies with transparent grapheme-phoneme relations, to deep orthographies, in which these relations are opaque. Only a few studies have examined whether orthographic depth is reflected in brain activity. In these studies a between-language design was applied, making it difficult to isolate the aspect of orthographic depth. In the present work this question was examined using a within-subject-and-language investigation. The participants were speakers of Hebrew, as they are skilled in reading two forms of script transcribing the same oral language. One form is the shallow pointed script (with diacritics, and the other is the deep unpointed script (without diacritics. Event-related potentials (ERPs were recorded while skilled readers carried out a lexical decision task in the two forms of script. A visual non-orthographic task controlled for the visual difference between the scripts (resulting from the addition of diacritics to the pointed script only. At an early visual-perceptual stage of processing (~165 ms after target onset, the pointed script evoked larger amplitudes with longer latencies than the unpointed script at occipital-temporal sites. However, these effects were not restricted to orthographic processing, and may therefore have reflected, at least in part, the visual load imposed by the diacritics. Nevertheless, the results implied that distinct orthographic processing may have also contributed to these effects. At later stages (~340 ms after target onset the unpointed script elicited larger amplitudes than the pointed one with earlier latencies. As this latency has been linked to orthographic-linguistic processing and to the classification of stimuli, it is suggested that these differences are associated with distinct lexical processing of a shallow and a deep orthography.

  10. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, S.V.; Changeux, J.P.; Granon, S. [Unite de Neurobiologie Integrative du Systeme Cholinergique, URA CNRS 2182, Institut Pasteur, Departement de Neuroscience, 25 rue du Dr Roux, 75015 Paris (France); Amadon, A.; Giacomini, E.; Le Bihan, D. [Service Hospitalier Frederic Joliot, 4 place du general Leclerc, 91400 Orsay (France); Wiklund, A. [Section of Anaesthesiology and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm (Sweden)

    2009-07-01

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity {beta}2-containing nicotinic receptors ({beta}2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the {beta}2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and {beta}2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, {beta}2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via {alpha}7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on {beta}2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  11. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

    International Nuclear Information System (INIS)

    Suarez, S.V.; Changeux, J.P.; Granon, S.; Amadon, A.; Giacomini, E.; Le Bihan, D.; Wiklund, A.

    2009-01-01

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity β2-containing nicotinic receptors (β2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the β2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and β2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, β2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via α7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on β2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  12. Rivalry of homeostatic and sensory-evoked emotions: Dehydration attenuates olfactory disgust and its neural correlates.

    Science.gov (United States)

    Meier, Lea; Friedrich, Hergen; Federspiel, Andrea; Jann, Kay; Morishima, Yosuke; Landis, Basile Nicolas; Wiest, Roland; Strik, Werner; Dierks, Thomas

    2015-07-01

    Neural correlates have been described for emotions evoked by states of homeostatic imbalance (e.g. thirst, hunger, and breathlessness) and for emotions induced by external sensory stimulation (such as fear and disgust). However, the neurobiological mechanisms of their interaction, when they are experienced simultaneously, are still unknown. We investigated the interaction on the neurobiological and the perceptional level using subjective ratings, serum parameters, and functional magnetic resonance imaging (fMRI) in a situation of emotional rivalry, when both a homeostatic and a sensory-evoked emotion were experienced at the same time. Twenty highly dehydrated male subjects rated a disgusting odor as significantly less repulsive when they were thirsty. On the neurobiological level, we found that this reduction in subjective disgust during thirst was accompanied by a significantly reduced neural activity in the insular cortex, a brain area known to be considerably involved in processing of disgust. Furthermore, during the experience of disgust in the satiated condition, we observed a significant functional connectivity between brain areas responding to the disgusting odor, which was absent during the stimulation in the thirsty condition. These results suggest interference of conflicting emotions: an acute homeostatic imbalance can attenuate the experience of another emotion evoked by the sensory perception of a potentially harmful external agent. This finding offers novel insights with regard to the behavioral relevance of biologically different types of emotions, indicating that some types of emotions are more imperative for behavior than others. As a general principle, this modulatory effect during the conflict of homeostatic and sensory-evoked emotions may function to safeguard survival. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Words in melody: an H(2)15O PET study of brain activation during singing and speaking.

    Science.gov (United States)

    Jeffries, K J; Fritz, J B; Braun, A R

    2003-04-15

    We used H(2)15O PET to characterize the interaction of words and melody by comparing brain activity measured while subjects spoke or sang the words to a familiar song. Relative increases in activity during speaking vs singing were observed in the left hemisphere, in classical perisylvian language areas including the posterior superior temporal gyrus, supramarginal gyrus, and frontal operculum, as well as in Rolandic cortices and putamen. Relative increases in activity during singing were observed in the right hemisphere: these were maximal in the right anterior superior temporal gyrus and contiguous portions of the insula; relative increases associated with singing were also detected in the right anterior middle temporal gyrus and superior temporal sulcus, medial and dorsolateral prefrontal cortices, mesial temporal cortices and cerebellum, as well as in Rolandic cortices and nucleus accumbens. These results indicate that the production of words in song is associated with activation of regions within right hemisphere areas that are not mirror-image homologues of left hemisphere perisylvian language areas, and suggest that multiple neural networks may be involved in different aspects of singing. Right hemisphere mechanisms may support the fluency-evoking effects of singing in neurological disorders such as stuttering or aphasia.

  14. Psychological and physiological responses to odor-evoked autobiographic memory.

    Science.gov (United States)

    Matsunaga, Masahiro; Isowa, Tokiko; Yamakawa, Kaori; Kawanishi, Yoko; Tsuboi, Hirohito; Kaneko, Hiroshi; Sadato, Norihiro; Oshida, Akiko; Katayama, Atsushi; Kashiwagi, Mitsuyoshi; Ohira, Hideki

    2011-01-01

    The "Proust phenomenon" occurs when a certain smell evokes a specific memory. Recent studies have demonstrated that odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli because of the direct neural communication between the olfactory system and the amygdala. The amygdala is known to regulate various physiological activities including the endocrine and immune systems; therefore, odor-evoked autobiographic memory may trigger various psychological and physiological responses; however, the responses elicited by this memory remains obscure. In this study, we aimed to investigate the psychological and physiological responses accompanying odor-evoked autobiographic memory. We recruited healthy male and female volunteers and investigated changes in their mood states and autonomic nervous, endocrine, and immune activities when autobiographic memory was evoked in the participants by asking them to smell an odor(s) that was nostalgic to them. The autobiographic memories associated with positive emotion resulted in increased positive mood states, such as comfort and happiness, and decreased negative mood states, such as anxiety. Furthermore, heart rate was decreased, skin-conductance level was increased, and peripheral interleukin-2 level was decreased after smelling the nostalgic odor. These psychological and physiological responses were significantly correlated. The present study suggests that odor-evoked autobiographic memory along with a positive feeling induce various physiological responses, including the autonomic nervous and immune activities. To the best of our knowledge, the present study is the first to observe an interaction between odor-evoked autobiographic memories and immune function.

  15. NADPH Oxidase 2 Regulates NLRP3 Inflammasome Activation in the Brain after Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Merry W. Ma

    2017-01-01

    Full Text Available Traumatic brain injury (TBI is a leading cause of death and disability worldwide. After the initial primary mechanical injury, a complex secondary injury cascade involving oxidative stress and neuroinflammation follows, which may exacerbate the injury and complicate the healing process. NADPH oxidase 2 (NOX2 is a major contributor to oxidative stress in TBI pathology, and inhibition of NOX2 is neuroprotective. The NLRP3 inflammasome can become activated in response to oxidative stress, but little is known about the role of NOX2 in regulating NLRP3 inflammasome activation following TBI. In this study, we utilized NOX2 knockout mice to study the role of NOX2 in mediating NLRP3 inflammasome expression and activation following a controlled cortical impact. Expression of NLRP3 inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC, as well as its downstream products cleaved caspase-1 and interleukin-1β (IL-1β, was robustly increased in the injured cerebral cortex following TBI. Deletion of NOX2 attenuated the expression, assembly, and activity of the NLRP3 inflammasome via a mechanism that was associated with TXNIP, a sensor of oxidative stress. The results support the notion that NOX2-dependent inflammasome activation contributes to TBI pathology.

  16. Covert waking brain activity reveals instantaneous sleep depth.

    Directory of Open Access Journals (Sweden)

    Scott M McKinney

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

  17. Comparison of evoked vs. spontaneous tics in a patient with trigeminal neuralgia (tic doloureux

    Directory of Open Access Journals (Sweden)

    Aiello-Lammens Matthew

    2007-11-01

    Full Text Available Abstract A 53-year old woman with tic doloureaux, affecting her right maxillary division of the trigeminal nerve (V2, could elicit shooting pains by slightly tapping her teeth when off medication. The pains, which she normally rated as > 6/10 on a visual analog scale (VAS, were electric shock-like in nature. She had no other spontaneous or ongoing background pain affecting the region. Based on her ability to elicit these tics, functional magnetic resonance imaging (fMRI was performed while she produced brief shocks every 2 minutes on cue (evoked pain over a 20 min period. In addition, she had 1–2 spontaneous shocks manifested between these evoked pains over the course of functional image acquisition. Increased fMRI activation for both evoked and spontaneous tics was observed throughout cortical and subcortical structures commonly observed in experimental pain studies with healthy subjects; including the primary somatosensory cortex, insula, anterior cingulate, and thalamus. Spontaneous tics produced more decrease in signals in a number of regions including the posterior cingulate cortex and amygdala, suggesting that regions known to be involved in expectation/anticipation may have been activated for the evoked, but not spontaneous, tics. In this patient there were large increases in activation observed in the frontal regions, including the anterior cingulate cortex and the basal ganglia. Spontaneous tics showed increased activation in classic aversion circuitry that may contribute to increased levels of anxiety. We believe that this is the first report of functional imaging of brain changes in tic-doloureaux.

  18. The Impact of Glial Activation in the Aging Brain

    Science.gov (United States)

    Lynch, Aileen M.; Murphy, Kevin J.; Deighan, Brian F.; O'Reilly, Julie-Ann.; Gun'ko, Yuri K.; Cowley, Thelma R.; Gonzalez-Reyes, Rodrigo E.; Lynch, Marina A.

    2010-01-01

    The past decade or so has witnessed a rekindling of interest in glia requiring a re-evaluation of the early descriptions of astrocytes as merely support cells, and microglia as adopting either a resting state or an activated state in a binary fashion. We now know that both cell types contribute to the optimal functioning of neurons in the healthy brain, and that altered function of either cell impacts on neuronal function and consequently cognitive function. The evidence indicates that both astrocytic and microglial phenotype change with age and that the shift from the resting state is associated with deterioration in synaptic function. In this review, we consider the rapidly-expanding array of functions attributed to these cells and focus on evaluating the changes in cell activation that accompany ageing. PMID:22396865

  19. From emotion perception to emotion experience: emotions evoked by pictures and classical music.

    Science.gov (United States)

    Baumgartner, Thomas; Esslen, Michaela; Jäncke, Lutz

    2006-04-01

    Most previous neurophysiological studies evoked emotions by presenting visual stimuli. Models of the emotion circuits in the brain have for the most part ignored emotions arising from musical stimuli. To our knowledge, this is the first emotion brain study which examined the influence of visual and musical stimuli on brain processing. Highly arousing pictures of the International Affective Picture System and classical musical excerpts were chosen to evoke the three basic emotions of happiness, sadness and fear. The emotional stimuli modalities were presented for 70 s either alone or combined (congruent) in a counterbalanced and random order. Electroencephalogram (EEG) Alpha-Power-Density, which is inversely related to neural electrical activity, in 30 scalp electrodes from 24 right-handed healthy female subjects, was recorded. In addition, heart rate (HR), skin conductance responses (SCR), respiration, temperature and psychometrical ratings were collected. Results showed that the experienced quality of the presented emotions was most accurate in the combined conditions, intermediate in the picture conditions and lowest in the sound conditions. Furthermore, both the psychometrical ratings and the physiological involvement measurements (SCR, HR, Respiration) were significantly increased in the combined and sound conditions compared to the picture conditions. Finally, repeated measures ANOVA revealed the largest Alpha-Power-Density for the sound conditions, intermediate for the picture conditions, and lowest for the combined conditions, indicating the strongest activation in the combined conditions in a distributed emotion and arousal network comprising frontal, temporal, parietal and occipital neural structures. Summing up, these findings demonstrate that music can markedly enhance the emotional experience evoked by affective pictures.

  20. Qualitative and quantitative measurement of brain activity associated with visual sexual arousal in males and females: 3.0 tesIa functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Joong; Jeong, Gwang Woo; Eun, Sung Jong; Cho, Seong Hoon; Seo, Jeong Jin; Kang, Heoung Keun; Park, Kwang Sung [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of)

    2004-08-01

    The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3- minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0T MR scanner. The overall lateralization index of activation shows left predominance (LI= 35.3%) in

  1. Qualitative and quantitative measurement of brain activity associated with visual sexual arousal in males and females: 3.0 tesIa functional MR imaging

    International Nuclear Information System (INIS)

    Kim, Hyung Joong; Jeong, Gwang Woo; Eun, Sung Jong; Cho, Seong Hoon; Seo, Jeong Jin; Kang, Heoung Keun; Park, Kwang Sung

    2004-01-01

    The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3- minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0T MR scanner. The overall lateralization index of activation shows left predominance (LI= 35.3%) in

  2. Stromal Interaction Molecule 1 (STIM1) and Orai1 Mediate Histamine-evoked Calcium Entry and Nuclear Factor of Activated T-cells (NFAT) Signaling in Human Umbilical Vein Endothelial Cells*

    Science.gov (United States)

    Zhou, Meng-Hua; Zheng, Hongying; Si, Hongjiang; Jin, Yixin; Peng, Jasmine M.; He, Lian; Zhou, Yubin; Muñoz-Garay, Carlos; Zawieja, David C.; Kuo, Lih; Peng, Xu; Zhang, Shenyuan L.

    2014-01-01

    Histamine is an important immunomodulator involved in allergic reactions and inflammatory responses. In endothelial cells, histamine induces Ca2+ mobilization by releasing Ca2+ from the endoplasmic reticulum and eliciting Ca2+ entry across the plasma membrane. Herein, we show that histamine-evoked Ca2+ entry in human umbilical vein endothelial cells (HUVECs) is sensitive to blockers of Ca2+ release-activated Ca2+ (CRAC) channels. RNA interference against STIM1 or Orai1, the activating subunit and the pore-forming subunit of CRAC channels, respectively, abolishes this histamine-evoked Ca2+ entry. Furthermore, overexpression of dominant-negative CRAC channel subunits inhibits while co-expression of both STIM1 and Orai1 enhances histamine-induced Ca2+ influx. Interestingly, gene silencing of STIM1 or Orai1 also interrupts the activation of calcineurin/nuclear factor of activated T-cells (NFAT) pathway and the production of interleukin 8 triggered by histamine in HUVECs. Collectively, these results suggest a central role of STIM1 and Orai1 in mediating Ca2+ mobilization linked to inflammatory signaling of endothelial cells upon histamine stimulation. PMID:25190815

  3. Brain Activity and Functional Connectivity Associated with Hypnosis.

    Science.gov (United States)

    Jiang, Heidi; White, Matthew P; Greicius, Michael D; Waelde, Lynn C; Spiegel, David

    2017-08-01

    Hypnosis has proven clinical utility, yet changes in brain activity underlying the hypnotic state have not yet been fully identified. Previous research suggests that hypnosis is associated with decreased default mode network (DMN) activity and that high hypnotizability is associated with greater functional connectivity between the executive control network (ECN) and the salience network (SN). We used functional magnetic resonance imaging to investigate activity and functional connectivity among these three networks in hypnosis. We selected 57 of 545 healthy subjects with very high or low hypnotizability using two hypnotizability scales. All subjects underwent four conditions in the scanner: rest, memory retrieval, and two different hypnosis experiences guided by standard pre-recorded instructions in counterbalanced order. Seeds for the ECN, SN, and DMN were left and right dorsolateral prefrontal cortex, dorsal anterior cingulate cortex (dACC), and posterior cingulate cortex (PCC), respectively. During hypnosis there was reduced activity in the dACC, increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC;ECN) and the insula in the SN, and reduced connectivity between the ECN (DLPFC) and the DMN (PCC). These changes in neural activity underlie the focused attention, enhanced somatic and emotional control, and lack of self-consciousness that characterizes hypnosis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Rapid and low-invasive functional brain mapping by realtime visualization of high gamma activity for awake craniotomy.

    Science.gov (United States)

    Kamada, K; Ogawa, H; Kapeller, C; Prueckl, R; Guger, C

    2014-01-01

    For neurosurgery with an awake craniotomy, the critical issue is to set aside enough time to identify eloquent cortices by electrocortical stimulation (ECS). High gamma activity (HGA) ranging between 80 and 120 Hz on electrocorticogram (ECoG) is assumed to reflect localized cortical processing. In this report, we used realtime HGA mapping and functional magnetic resonance imaging (fMRI) for rapid and reliable identification of motor and language functions. Three patients with intra-axial tumors in their dominant hemisphere underwent preoperative fMRI and lesion resection with an awake craniotomy. All patients showed significant fMRI activation evoked by motor and language tasks. After the craniotomy, we recorded ECoG activity by placing subdural grids directly on the exposed brain surface. Each patient performed motor and language tasks and demonstrated realtime HGA dynamics in hand motor areas and parts of the inferior frontal gyrus. Sensitivity and specificity of HGA mapping were 100% compared to ECS mapping in the frontal lobe, which suggested HGA mapping precisely indicated eloquent cortices. The investigation times of HGA mapping was significantly shorter than that of ECS mapping. Specificities of the motor and language-fMRI, however, did not reach 85%. The results of HGA mapping was mostly consistent with those of ECS mapping, although fMRI tended to overestimate functional areas. This novel technique enables rapid and accurate functional mapping.

  5. Brain activation by music in patients in a vegetative or minimally conscious state following diffuse brain injury.

    Science.gov (United States)

    Okumura, Yuka; Asano, Yoshitaka; Takenaka, Shunsuke; Fukuyama, Seisuke; Yonezawa, Shingo; Kasuya, Yukinori; Shinoda, Jun

    2014-01-01

    The aim of this study was to objectively evaluate the brain activity potential of patients with impaired consciousness in a chronic stage of diffuse brain injury (DBI) using functional MRI (fMRI) following music stimulation (MS). Two patients in a minimally conscious state (MCS) and five patients in a vegetative state (VS) due to severe DBI were enrolled along with 21 healthy adults. This study examined the brain regions activated by music and assessed topographical differences of the MS-activated brain among healthy adults and these patients. MS was shown to activate the bilateral superior temporal gyri (STG) of both healthy adults and patients in an MCS. In four of five patients in a VS, however, no significant activation in STG could be induced by the same MS. The remaining patient in a VS displayed the same MS-induced brain activation in STG as healthy adults and patients in an MCS and this patient's status also improved to an MCS 4 months after the study. The presence of STG activation by MS may predict a possible improvement of patients in a VS to MCS and fMRI employing MS may be a useful modality to objectively evaluate consciousness in these patients.

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

    Science.gov (United States)

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

    2015-02-15

    An important function of eating is ingesting energy. Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three stimuli in two motivational states (hunger and satiety) while their brain responses were measured using functional magnetic resonance imaging in a randomized crossover design. Stimuli were solutions of sucralose (sweet, no energy), maltodextrin (non-sweet, energy) and sucralose+maltodextrin (sweet, energy). We found no main effect of energy content and no interaction between energy content and sweetness. However, there was an interaction between hunger state and energy content in the median cingulate (bilaterally), ventrolateral prefrontal cortex, anterior insula and thalamus. This indicates that the anterior insula and thalamus, areas in which hunger state and taste of a stimulus are integrated, also integrate hunger state with caloric content of a taste stimulus. Furthermore, in the median cingulate and ventrolateral prefrontal cortex, tasting energy resulted in more activation during satiety compared to hunger. This finding indicates that these areas, which are known to be involved in processes that require approach and avoidance, are also involved in guiding ingestive behavior. In conclusion, our results suggest that energy sensing is a hunger state dependent process, in which the median cingulate, ventrolateral prefrontal cortex, anterior insula and thalamus play a central role by integrating hunger state with stimulus relevance. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Neurofeedback tunes scale-free dynamics in spontaneous brain activity

    NARCIS (Netherlands)

    Ros, T.; Frewen, P.A.; Thé berge, J.; Michela, A.; Kluetsch, R.C.; Mü ller, A.; Candrian, G.; Jetly, R.; Vuilleumier, P.; Lanius, R.

    2017-01-01

    Brain oscillations exhibit long-range temporal correlations (LRTCs), which reflect the regularity of their fluctuations: low values representing more random (decorrelated) while high values more persistent (correlated) dynamics. LRTCs constitute supporting evidence that the brain operates near

  8. Genetic and environmental contributions to brain activation during calculation.

    Science.gov (United States)

    Pinel, Philippe; Dehaene, Stanislas

    2013-11-01

    Twin studies have long suggested a genetic influence on inter-individual variations in mathematical abilities, and candidate genes have been identified by genome-wide association studies. However, the localization of the brain regions under genetic influence during number manipulation is still unexplored. Here we investigated fMRI data from a group of 19 MZ (monozygotic) and 13 DZ (dizygotic) adult twin pairs, scanned during a mental calculation task. We examined both the activation and the degree of functional lateralization in regions of interest (ROIs) centered on the main activated peaks. Heritability was first investigated by comparing the respective MZ and DZ correlations. Then, genetic and environmental contributions were jointly estimated by fitting a ACE model classically used in twin studies. We found that a subset of the activated network was under genetic influence, encompassing the bilateral posterior superior parietal lobules (PSPL), the right intraparietal sulcus (IPS) and a left superior frontal region. An additional region of the left inferior parietal cortex (IPC), whose deactivation correlated with a behavioral calculation score, also presented higher similarity between MZ than between DZ twins, thus offering a plausible physiological basis for the observable inheritance of math scores. Finally, the main impact of the shared environment was found in the lateralization of activation within the intraparietal sulcus. These maps of genetic and environmental contributions provide precise candidate phenotypes for further genetic association analyses, and illuminate how genetics and education shape the development of number processing networks. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Baseline and cognition activated brain SPECT imaging in depression

    International Nuclear Information System (INIS)

    Zhao Jinhua; Lin Xiangtong; Jiang Kaida; Liu Yongchang; Xu Lianqin

    1998-01-01

    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 99m Tc-ECD SPECT were performed on 21 of the 27 patients with depression and 13 of the 15 normal controls. Baseline 99m Tc-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 99m Tc-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

  10. Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy.

    Science.gov (United States)

    Tamura, Yukie; Ogawa, Hiroshi; Kapeller, Christoph; Prueckl, Robert; Takeuchi, Fumiya; Anei, Ryogo; Ritaccio, Anthony; Guger, Christoph; Kamada, Kyousuke

    2016-12-01

    OBJECTIVE Electrocortical stimulation (ECS) is the gold standard for functional brain mapping; however, precise functional mapping is still difficult in patients with language deficits. High gamma activity (HGA) between 80 and 140 Hz on electrocorticography is assumed to reflect localized cortical processing, whereas the cortico-cortical evoked potential (CCEP) can reflect bidirectional responses evoked by monophasic pulse stimuli to the language cortices when there is no patient cooperation. The authors propose the use of "passive" mapping by combining HGA mapping and CCEP recording without active tasks during conscious resections of brain tumors. METHODS Five patients, each with an intraaxial tumor in their dominant hemisphere, underwent conscious resection of their lesion with passive mapping. The authors performed functional localization for the receptive language area, using real-time HGA mapping, by listening passively to linguistic sounds. Furthermore, single electrical pulses were delivered to the identified receptive temporal language area to detect CCEPs in the frontal lobe. All mapping results were validated by ECS, and the sensitivity and specificity were evaluated. RESULTS Linguistic HGA mapping quickly identified the language area in the temporal lobe. Electrical stimulation by linguistic HGA mapping to the identified temporal receptive language area evoked CCEPs on the frontal lobe. The combination of linguistic HGA and frontal CCEPs needed no patient cooperation or effort. In this small case series, the sensitivity and specificity were 93.8% and 89%, respectively. CONCLUSIONS The described technique allows for simple and quick functional brain mapping with higher sensitivity and specificity than ECS mapping. The authors believe that this could improve the reliability of functional brain mapping and facilitate rational and objective operations. Passive mapping also sheds light on the underlying physiological mechanisms of language in the human brain.

  11. Testosterone Is Inversely Related to Brain Activity during Emotional Inhibition in Schizophrenia

    OpenAIRE

    Vercammen, Ans; Skilleter, Ashley J.; Lenroot, Rhoshel; Catts, Stanley V.; Weickert, Cynthia Shannon; Weickert, Thomas W.

    2013-01-01

    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...

  12. Ageing diminishes the modulation of human brain responses to visual food cues by meal ingestion.

    Science.gov (United States)

    Cheah, Y S; Lee, S; Ashoor, G; Nathan, Y; Reed, L J; Zelaya, F O; Brammer, M J; Amiel, S A

    2014-09-01

    Rates of obesity are greatest in middle age. Obesity is associated with altered activity of brain networks sensing food-related stimuli and internal signals of energy balance, which modulate eating behaviour. The impact of healthy mid-life ageing on these processes has not been characterised. We therefore aimed to investigate changes in brain responses to food cues, and the modulatory effect of meal ingestion on such evoked neural activity, from young adulthood to middle age. Twenty-four healthy, right-handed subjects, aged 19.5-52.6 years, were studied on separate days after an overnight fast, randomly receiving 50 ml water or 554 kcal mixed meal before functional brain magnetic resonance imaging while viewing visual food cues. Across the group, meal ingestion reduced food cue-evoked activity of amygdala, putamen, insula and thalamus, and increased activity in precuneus and bilateral parietal cortex. Corrected for body mass index, ageing was associated with decreasing food cue-evoked activation of right dorsolateral prefrontal cortex (DLPFC) and precuneus, and increasing activation of left ventrolateral prefrontal cortex (VLPFC), bilateral temporal lobe and posterior cingulate in the fasted state. Ageing was also positively associated with the difference in food cue-evoked activation between fed and fasted states in the right DLPFC, bilateral amygdala and striatum, and negatively associated with that of the left orbitofrontal cortex and VLPFC, superior frontal gyrus, left middle and temporal gyri, posterior cingulate and precuneus. There was an overall tendency towards decreasing modulatory effects of prior meal ingestion on food cue-evoked regional brain activity with increasing age. Healthy ageing to middle age is associated with diminishing sensitivity to meal ingestion of visual food cue-evoked activity in brain regions that represent the salience of food and direct food-associated behaviour. Reduced satiety sensing may have a role in the greater risk of

  13. 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.

  14. Role of synchronized oscillatory brain activity for human pain perception.

    Science.gov (United States)

    Hauck, Michael; Lorenz, Jürgen; Engel, Andreas K

    2008-01-01

    The understanding of cortical pain processing in humans has significantly improved since the development of modern neuroimaging techniques. Non-invasive electrophysiological approaches such as electro- and magnetoencephalography have proven to be helpful tools for the real-time investigation of neuronal signals and synchronous communication between cortical areas. In particular, time-frequency decomposition of signals recorded with these techniques seems to be a promising approach because different pain-related oscillatory changes can be observed within different frequency bands, which are likely to be linked to specific sensory and motor functions. In this review we discuss the latest evidence on pain-induced time-frequency signals and propose that changes in oscillatory activity reflect an essential communication mechanism in the brain that is modulated during pain processing. The importance of synchronization processes for normal and pathological pain processing, such as chronic pain states, is discussed.

  15. Task Context Influences Brain Activation during Music Listening

    Directory of Open Access Journals (Sweden)

    Andjela Markovic

    2017-06-01

    Full Text Available In this paper, we examined brain activation in subjects during two music listening conditions: listening while simultaneously rating the musical piece being played [Listening and Rating (LR] and listening to the musical pieces unconstrained [Listening (L]. Using these two conditions, we tested whether the sequence in which the two conditions were fulfilled influenced the brain activation observable during the L condition (LR → L or L → LR. We recorded high-density EEG during the playing of four well-known positively experienced soundtracks in two subject groups. One group started with the L condition and continued with the LR condition (L → LR; the second group performed this experiment in reversed order (LR → L. We computed from the recorded EEG the power for different frequency bands (theta, lower alpha, upper alpha, lower beta, and upper beta. Statistical analysis revealed that the power in all examined frequency bands increased during the L condition but only when the subjects had not had previous experience with the LR condition (i.e., L → LR. For the subjects who began with the LR condition, there were no power increases during the L condition. Thus, the previous experience with the LR condition prevented subjects from developing the particular mental state associated with the typical power increase in all frequency bands. The subjects without previous experience of the LR condition listened to the musical pieces in an unconstrained and undisturbed manner and showed a general power increase in all frequency bands. We interpret the fact that unconstrained music listening was associated with increased power in all examined frequency bands as a neural indicator of a mental state that can best be described as a mind-wandering state during which the subjects are “drawn into” the music.

  16. 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

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

    DEFF Research Database (Denmark)

    Benveniste, Helene; Fowler, Joanna S; Rooney, William D

    2010-01-01

    -trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide...... evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine's effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine...

  18. Brain Activation Underlying Threat Detection to Targets of Different Races

    Science.gov (United States)

    Senholzi, Keith B.; Depue, Brendan E.; Correll, Joshua; Banich, Marie T.; Ito, Tiffany A.

    2016-01-01

    The current study examined blood oxygen level dependent (BOLD) signal underlying racial differences in threat detection. During fMRI, participants determined whether pictures of Black or White individuals held weapons. They were instructed to make shoot responses when the picture showed armed individuals but don’t shoot responses to unarmed individuals, with the cost of not shooting armed individuals being greater than that of shooting unarmed individuals. Participants were faster to shoot armed Blacks than Whites, but faster in making don’t shoot responses to unarmed Whites than Blacks. Brain activity differed to armed versus unarmed targets depending on target race, suggesting different mechanisms underlying threat versus safety decisions. Anterior cingulate cortex was preferentially engaged for unarmed Whites than Blacks. Parietal and visual cortical regions exhibited greater activity for armed Blacks than Whites. Seed-based functional connectivity of the amygdala revealed greater coherence with parietal and visual cortices for armed Blacks than Whites. Furthermore, greater implicit Black-danger associations were associated with increased amygdala activation to armed Blacks, compared to armed Whites. Our results suggest that different neural mechanisms may underlie racial differences in responses to armed versus unarmed targets. PMID:26357911

  19. Brain activation during compassion meditation: a case study.

    Science.gov (United States)

    Engström, Maria; Söderfeldt, Birgitta

    2010-05-01

    B.L. is a Tibetan Buddhist with many years of compassion meditation practice. During meditation B.L. uses a technique to generate a feeling of love and compassion while reciting a mantra. The aim of the present study was to investigate the neural correlates of compassion meditation in 1 experienced meditator. B.L. was examined by functional magnetic resonance imaging during compassion meditation, applying a paradigm with meditation and word repetition blocks. The most significant finding was the activation in the left medial prefrontal cortex extending to the anterior cingulate gyrus. Other significant loci of activation were observed in the right caudate body extending to the right insula and in the left midbrain close to the hypothalamus. The results in this study are in concordance with the hypothesis that compassion meditation is accompanied by activation in brain areas involved with empathy as well as with happy and pleasant feelings (i.e., the left medial prefrontal cortex and the anterior cingulate gyrus).

  20. Own-gender imitation activates the brain's reward circuitry.

    Science.gov (United States)

    Losin, Elizabeth A Reynolds; Iacoboni, Macro; Martin, Alia; Dapretto, Mirella

    2012-10-01

    Imitation is an important component of human social learning throughout life. Theoretical models and empirical data from anthropology and psychology suggest that people tend to imitate self-similar individuals, and that such imitation biases increase the adaptive value (e.g., self-relevance) of learned information. It is unclear, however, what neural mechanisms underlie people's tendency to imitate those similar to themselves. We focused on the own-gender imitation bias, a pervasive bias thought to be important for gender identity development. While undergoing fMRI, participants imitated own- and other-gender actors performing novel, meaningless hand signs; as control conditions, they also simply observed such actions and viewed still portraits of the same actors. Only the ventral and dorsal striatum, orbitofrontal cortex and amygdala were more active when imitating own- compared to other-gender individuals. A Bayesian analysis of the BrainMap neuroimaging database demonstrated that the striatal region preferentially activated by own-gender imitation is selectively activated by classical reward tasks in the literature. Taken together, these findings reveal a neurobiological mechanism associated with the own-gender imitation bias and demonstrate a novel role of reward-processing neural structures in social behavior.

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

    Science.gov (United States)

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

    2015-07-01

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

  2. Brain activity accompanying perception of implied motion in abstract paintings.

    Science.gov (United States)

    Kim, Chai-Youn; Blake, Randolph

    2007-01-01

    Early 20th century artists including Duchamp and Balla tried to portray moving objects on a static canvas by superimposing objects in successive portrayals of an action. We investigated whether implied motion in those paintings is associated with activation of motion-sensitive area MT+. In Experiment 1, we found that observers rated these kinds of paintings higher in portraying motion than they did other abstract paintings in which motion is not intended. We also found that observers who had previously experienced abstract paintings with implied motion tended to give higher motion ratings to that class of paintings. In Experiment 2, we used functional magnetic resonance imaging (fMRI) to measure brain activity of observers while viewing abstract paintings receiving the highest and the lowest motion rating scores in Experiment 1. We found MT+, but not primary visual cortex (V1), showed greater BOLD responses to abstract paintings with implied motion than to abstract paintings with little motion impression, but only in observers with prior experience viewing those kinds of paintings. These results imply that the neural machinery ordinarily engaged during perception of real visual motion is activated when people view paintings explicitly designed to convey a sense of visual motion. Experience, however, is necessary to achieve this sense of motion.

  3. Neural signatures of social conformity: A coordinate-based activation likelihood estimation meta-analysis of functional brain imaging studies.

    Science.gov (United States)

    Wu, Haiyan; Luo, Yi; Feng, Chunliang

    2016-12-01

    People often align their behaviors with group opinions, known as social conformity. Many neuroscience studies have explored the neuropsychological mechanisms underlying social conformity. Here we employed a coordinate-based meta-analysis on neuroimaging studies of social conformity with the purpose to reveal the convergence of the underlying neural architecture. We identified a convergence of reported activation foci in regions associated with normative decision-making, including ventral striatum (VS), dorsal posterior medial frontal cortex (dorsal pMFC), and anterior insula (AI). Specifically, consistent deactivation of VS and activation of dorsal pMFC and AI are identified when people's responses deviate from group opinions. In addition, the deviation-related responses in dorsal pMFC predict people's conforming behavioral adjustments. These are consistent with current models that disagreement with others might evoke "error" signals, cognitive imbalance, and/or aversive feelings, which are plausibly detected in these brain regions as control signals to facilitate subsequent conforming behaviors. Finally, group opinions result in altered neural correlates of valuation, manifested as stronger responses of VS to stimuli endorsed than disliked by others. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Long-term depression of climbing fiber-evoked calcium transients in Purkinje cell dendrites

    Science.gov (United States)

    Weber, John T.; De Zeeuw, Chris I.; Linden, David J.; Hansel, Christian

    2003-01-01

    In recent years much has been learned about the molecular requirements for inducing long-term synaptic depression (LTD) in various brain regions. However, very little is known about the consequences of LTD induction for subsequent signaling events in postsynaptic neurons. We have addressed this issue by examining homosynaptic LTD at the cerebellar climbing fiber (CF)–Purkinje cell (PC) synapse. This synapse is built for reliable and massive excitation: Activation of a single axon produces an unusually large α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor-mediated synaptic current, the depolarization of which drives a regenerative complex spike producing a large, widespread Ca2+ transient in PC dendrites. Here we test whether CF LTD has an impact on dendritic, complex spike-evoked Ca2+ signals by simultaneously performing long-term recordings of complex spikes and microfluorimetric Ca2+ measurements in PC dendrites in rat cerebellar slices. Our data show that LTD of the CF excitatory postsynaptic current produces a reduction in both slow components of the complex spike waveform and complex spike-evoked dendritic Ca2+ transients. This LTD of dendritic Ca2+ signals may provide a neuroprotective mechanism and/or constitute “heterosynaptic metaplasticity” by reducing the probability for subsequent induction of those forms of use-dependent plasticity, which require CF-evoked Ca2+ signals such as parallel fiber–PC LTD and interneuron–PC LTP. PMID:12601151

  5. Relationship between catalase activity and uptake of elemental mercury by rat brain

    International Nuclear Information System (INIS)

    Eide, I.; Syversen, T.L.M.

    1983-01-01

    Uptake of mercury by brain after intravenous injection of elemental mercury was investigated in the rat. Catalase activity was inhibited by aminotriazole either by intraperitoneal affecting catalase in most tissues of the animal or by intraventricular injections affecting catalase in the brain selectively. Uptake of elemental mercury by rat brain was not influenced by intraperitoneal administration of aminotriazole resulting in 50% inhibition of brain catalase. However, when the inhibitor was injected intraventricularly in concentrations to give a 50% inhibition of brain catalase, it was shown that the mercury uptake by brain was significantly decreased. In the latter case when only brain catalase was inhibited and the supply of elemtal mercury to brain was maintained, mercury uptake by brain was proportional to the activity of catalase in brain tissue and to the injected amount of elemental mercury. Contrary to the intraventricular injection of aminotriazole, in animals recieving aminotriazole intraperitoneally prior to elemental mercury injection, we suggest that the lower activity of brain catalse is compensated by an increased supply of elemtal mercury caused by the generally lower oxidation rate in the animal. This view is supported by the finding that mercury uptake by liver increased due to aminotriazole intraperitoneally although activity of catalase was depressed. (author)

  6. Evoked emotions predict food choice.

    Science.gov (United States)

    Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

  7. Multichannel brain recordings in behaving Drosophila reveal oscillatory activity and local coherence in response to sensory stimulation and circuit activation.

    Science.gov (United States)

    Paulk, Angelique C; Zhou, Yanqiong; Stratton, Peter; Liu, Li; van Swinderen, Bruno

    2013-10-01

    Neural networks in vertebrates exhibit endogenous oscillations that have been associated with functions ranging from sensory processing to locomotion. It remains unclear whether oscillations may play a similar role in the insect brain. We describe a novel "whole brain" readout for Drosophila melanogaster using a simple multichannel recording preparation to study electrical activity across the brain of flies exposed to different sensory stimuli. We recorded local field potential (LFP) activity from >2,000 registered recording sites across the fly brain in >200 wild-type and transgenic animals to uncover specific LFP frequency bands that correlate with: 1) brain region; 2) sensory modality (olfactory, visual, or mechanosensory); and 3) activity in specific neural circuits. We found endogenous and stimulus-specific oscillations throughout the fly brain. Central (higher-order) brain regions exhibited sensory modality-specific increases in power within narrow frequency bands. Conversely, in sensory brain regions such as the optic or antennal lobes, LFP coherence, rather than power, best defined sensory responses across modalities. By transiently activating specific circuits via expression of TrpA1, we found that several circuits in the fly brain modulate LFP power and coherence across brain regions and frequency domains. However, activation of a neuromodulatory octopaminergic circuit specifically increased neuronal coherence in the optic lobes during visual stimulation while decreasing coherence in central brain regions. Our multichannel recording and brain registration approach provides an effective way to track activity simultaneously across the fly brain in vivo, allowing investigation of functional roles for oscillations in processing sensory stimuli and modulating behavior.

  8. 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.

  9. 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.

  10. Brain activation during fear extinction predicts exposure success.

    Science.gov (United States)

    Ball, Tali Manber; Knapp, Sarah E; Paulus, Martin P; Stein, Murray B

    2017-03-01

    Exposure therapy, a gold-standard treatment for anxiety disorders, is assumed to work via extinction learning, but this has never been tested. Anxious individuals demonstrate extinction learning deficits, likely related to less ventromedial prefrontal cortex (vmPFC) and more amygdala activation, but the relationship between these deficits and exposure outcome is unknown. We tested whether anxious individuals who demonstrate better extinction learning report greater anxiety reduction following brief exposure. Twenty-four adults with public speaking anxiety completed (1) functional magnetic resonance imaging during a conditioning paradigm, (2) a speech exposure session, and (3) anxiety questionnaires before and two weeks postexposure. Extinction learning was assessed by comparing ratings to a conditioned stimulus (neutral image) that was previously paired with an aversive noise against a stimulus that had never been paired. Robust regression analyses examined whether brain activation during extinction learning predicted anxiety reduction two weeks postexposure. On average, the conditioning paradigm resulted in acquisition and extinction effects on stimulus ratings, and the exposure session resulted in reduced anxiety two weeks post-exposure. Consistent with our hypothesis, individuals with better extinction learning (less negative stimulus ratings), greater activation in vmPFC, and less activation in amygdala, insula, and periaqueductal gray reported greater anxiety reduction two weeks postexposure. To our knowledge, this is the first time that the theoretical link between extinction learning and exposure outcome has been demonstrated. Future work should examine whether extinction learning can be used as a prognostic test to determine who is most likely to benefit from exposure therapy. © 2016 Wiley Periodicals, Inc.

  11. 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.

  12. Experimental human endotoxemia enhances brain activity during social cognition.

    Science.gov (United States)

    Kullmann, Jennifer S; Grigoleit, Jan-Sebastian; Wolf, Oliver T; Engler, Harald; Oberbeck, Reiner; Elsenbruch, Sigrid; Forsting, Michael; Schedlowski, Manfred; Gizewski, Elke R

    2014-06-01

    Acute peripheral inflammation with corresponding increases in peripheral cytokines affects neuropsychological functions and induces depression-like symptoms. However, possible effects of increased immune responses on social cognition remain unknown. Therefore, this study investigated the effects of experimentally induced acute inflammation on performance and neural responses during a social cognition task assessing Theory of Mind (ToM) ability. In this double-blind randomized crossover functional magnetic resonance imaging study, 18 healthy right-handed male volunteers received an injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline, respectively. Plasma levels of pro- and anti-inflammatory cytokines as well as mood ratings were analyzed together with brain activation during a validated ToM task (i.e. Reading the Mind in the Eyes Test). LPS administration induced pronounced transient increases in pro- (IL-6, TNF-α) and anti-inflammatory (IL-10, IL-1ra) cytokines as well as decreases in mood. Social cognition performance was not affected by acute inflammation. However, altered neural activity was observed during the ToM task after LPS administration, reflected by increased responses in the fusiform gyrus, temporo-parietal junction, superior temporal gyrus and precuneus. The increased task-related neural responses in the LPS condition may reflect a compensatory strategy or a greater social cognitive processing as a function of sickness. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  13. Brain activation patterns during memory of cognitive agency.

    Science.gov (United States)

    Vinogradov, Sophia; Luks, Tracy L; Simpson, Gregory V; Schulman, Brian J; Glenn, Shenly; Wong, Amy E

    2006-06-01

    Agency is the awareness that one's own self is the agent or author of an action, a thought, or a feeling. The implicit memory that one's self was the originator of a cognitive event - the sense of cognitive agency - has not yet been fully explored in terms of relevant neural systems. In this functional magnetic resonance imaging (fMRI) study, we examined brain activation patterns differentiating memory for the source of previously self-generated vs. experimenter-presented word items from a sentence completion paradigm designed to be emotionally neutral and semantically constrained in content. Accurate memory for the source of self-generated vs. externally-presented word items resulted in activation of dorsal medial prefrontal cortex (mPFC) bilaterally, supporting an emerging body of work that indicates a key role for this region in self-referential processing. Our data extend the function of mPFC into the domain of memory and the accurate retrieval of the sense of cognitive agency under conditions where agency was encoded implicitly.

  14. 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 pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide...... evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine's effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine...

  15. Effect of a non lethal whole-body gamma irradiation on the spontaneous and evoked electroencephalographic activities of the adult rabbit; Effets d'une irradiation gamma globale non letale sur les activites electroencephalograpiques spontanees et evoquees du lapin adulte

    Energy Technology Data Exchange (ETDEWEB)

    Court, L. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    The whole of the experimental methods described (animal preparation, achievement of a precise physiological technique, dosimetry, biological information processing) allowed us to follow the changes for 15 days in the spontaneous and evoked electroencephalogram activities of rabbits submitted to a non-lethal 400 rads whole-body gamma-irradiation. Behavioural troubles, changes in the arousal state and the spontaneous electrical activity of the neo-cortex and hippocampus were noticed constantly together with an enhanced cortical excitability, and the appearance of elements of the paroxystic series sometimes in contrast with a general decrease in amplitude. After a visual stimulus the general morphology of evoked activities at the level of the primary visual areas and hippocampus was unchanged, but enhanced latencies and delays, less systematic modifications in amplitudes seemed to show out a direct effect of radiations on the nervous system and sensorial activities; these troubles seemed to occur independently from the basic electrical activity. As a whole, the changes observed were usually transitory and varied with each individual. Finally an assumption is made to explain the mechanism of arousal troubles and the general evolution of spontaneous electrical activity in the brain. (author) [French] 'L'ensemble des methodes experimentales decrites (preparation des animaux, mise au point d'une technique physiologique precise, dosimetrie, traitement de l'information biologique) a permis de suivre, pendant 15 jours, chez le lapin soumis a une irradiation gamma globale non letale de 400 rads, les modifications des activites electroencephaliques spontanees et evoquees. De facon constante, on note des troubles du comportement, des modifications de la vigilance et de l'activite electrique spontanee du neo-cortex et de l'hippocampe, ainsi qu'une augmentation de l'excitabilite corticale, l'apparition d'elements de la serie

  16. The Neural Association between Tendency to Forgive and Spontaneous Brain Activity in Healthy Young Adults

    OpenAIRE

    Haijiang Li; Jiamei Lu

    2017-01-01

    The tendency to forgive (TTF) refers to one’s global dispositional level of forgiveness across situations and relationships. Previous brain imaging studies examined activation patterns underlying forgiving process, yet the association between individual differences in the TTF and spontaneous brain activity at resting-state remains unknown. In this study, resting-state functional magnetic resonance imaging (fMRI) was used to investigate the correlation between the TTF and spontaneous brain act...

  17. Brain and behavioural evidence for rest-activity cycles in Octopus vulgaris.

    Science.gov (United States)

    Brown, Euan R; Piscopo, Stefania; De Stefano, Rosanna; Giuditta, Antonio

    2006-09-25

    Octopus vulgaris maintained under a 12/12h light/dark cycle exhibit a pronounced nocturnal activity pattern. Animals deprived of rest during the light period show a marked 'rebound' in activity in the following 24h. 'Active' octopuses attack faster than 'quiet' animals and brain activity recorded electrically intensifies during 'quiet' behaviour. Thus, in Octopus as in vertebrates, brain areas involved in memory or 'higher' processes exhibit 'off-line' activity during rest periods.

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

    International Nuclear Information System (INIS)

    Miyawaki, Yoichi; Uchida, Hajime; Yamashita, Okito; Sato, Masa-aki; Kamitani, Yukiyasu; Morito, Yusuke; Tanabe, Hiroki C; Sadato, Norihiro

    2009-01-01

    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 (2 100 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.

  19. In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function

    Science.gov (United States)

    Tang, Qinggong; Tsytsarev, Vassiliy; Liang, Chia-Pin; Akkentli, Fatih; Erzurumlu, Reha S.; Chen, Yu

    2015-11-01

    The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex (“barrels”), thalamus (“barreloids”), and brain stem (“barrelettes”). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.

  20. 3-Hydroxyanthranilate oxygenase activity is increased in the brains of Huntington disease victims

    International Nuclear Information System (INIS)

    Schwarcz, R.; Okuno, E.; White, R.J.; Bird, E.D.; Whetsell, W.O. Jr.

    1988-01-01

    An excess of the tryptophan metabolite quinolinic acid in the brain has been hypothetically related to the pathogenesis of Huntington disease. Quinolinate's immediate biosynthetic enzyme, 3-hydroxyanthranilate oxygenase, has now been detected in human brain tissue. The activity of 3-hydroxyanthranilate oxygenase is increased in Huntington disease brains as compared to control brains. The increment is particularly pronounced in the striatum, which is known to exhibit the most prominent nerve-cell loss in Huntington disease. Thus, the Huntington disease brain has a disproportionately high capability to produce the endogenous excitotoxin quinolinic acid. This finding may be of relevance for clinical, neuropathologic, and biochemical features associated with Huntington disease

  1. Perceptual learning: psychophysical thresholds and electrical brain topography.

    Science.gov (United States)

    Skrandies, W; Jedynak, A; Fahle, M

    2001-06-01

    We studied perceptual learning by determining psychophysical discrimination thresholds for visual hyper acuity targets (vernier stimuli) as a function of stimulus orientation. One aim was to relate perceptual improvements to changes of electrophysiological activity of the human brain. A group of 43 healthy adults participated in a psychophysical experiment where vernier thresholds for vertical and horizontal vernier targets were compared. In 16 subjects thresholds were measured for each orientation twice at an interval of 25 min. Between threshold estimations, evoked brain activity was recorded from 30 electrodes over the occipital brain areas while the subjects observed appearance and disappearance of supra-threshold vernier offsets. Mean evoked potentials were computed for the first and second 600 stimulus presentations, and the scalp topography of electrical brain activity was analyzed. Vertically oriented stimuli yielded significantly better performance than horizontal targets, and thresholds were significantly lower in the second half of the experiment, i.e. after prolonged viewing of stimuli. The improvements in discrimination performance were specific for stimulus orientation and did not generalize. Learning effects were also observed with electrical brain activity, and field strength of the potentials increased significantly as a function of time. Scalp topography of the evoked components was significantly affected indicating a shift of activation between different neuronal elements induced by perceptual learning.

  2. 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…

  3. Effects of sevoflurane on adenylate cyclase and phosphodiesterases activity in brain of rats

    International Nuclear Information System (INIS)

    Feng Changdong; Yang Jianping; Dai Tijun

    2009-01-01

    Objective: To investigate the effects of sevoflurane on c adenylate cyclase (AC) and phosphodiesterases (PDE) activity in the cerebrocortex, hippocampus and brain stem of rats, and to examine the role of cAMP in sevoflurane anesthesia. Methods: Fourty SD rats were delaminately designed and allocated randomly to 5 groups inhaling 1.5% sevoflurane i.e., no recovery (recovery group, n=8) and one hour after righting reflexrecovery (aware group, n=8). The brain tissues were rapidly dissected into cerebrocortex and hippocampus and brain stem.Then the adenylate cyclase and phosphodiesterases activity were assessed. Results: So far as the activity of AC is concerned, compared with the control group, the activity of AC in the cerebrocortex, hippocampus and brain stem brain stem of induction group and anesthesia group, the cerebrocortex, and hippocampus in the recovery group were significantly increased; compared with those in the anesthesia group, the activity of AC in the cerebrocortex, hippocampus and brain stem of aware group were significantly decreased (P<0.05); For the activity of PDE, compared with the control group, the activity of PDE in the cerebrocortex, hippocampus and brain stem in the induction group and anesthesia group was significantly decreased, compared with that in anesthesia group, the activity of PDE in the cerebrocortex, hippocampus and brain stem of recovery group and aware group was significantly increased (P<0.05). Conclusion: cAMP may play an important role in sevoflurane anesthesia. (authors)

  4. 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.

    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

  5. Brain Health

    Science.gov (United States)

    ... Brain Health Brain Health Home 10 Ways to Love Your Brain Stay Physically Active Adopt a Healthy Diet Stay ... risk factors slowed cognitive decline. 10 Ways to Love Your Brain > 10 tips to help reduce your risk of ...

  6. Casein kinase II activity in the brain of an insect, Acheta domesticus: characterization and hormonal regulation.

    Science.gov (United States)

    Degrelle, F; Renucci, M; Charpin, P; Tirard, A

    1997-01-01

    This study documented casein kinase II (CK II) activity in Acheta domesticus brain using specific antibodies and its regulation by polyamines. In control animals a transient decrease in CK II activity at day 3 after imaginal moult was observed in the brain but not in the fat body. If deprived of ecdysone by ovariectomy a different pattern was observed, with CK II activity being significantly higher on days 3 and 4 after emergence. After ecdysone injection in ovariectomized females, CK II activity decreased to levels similar to those in controls. The implications of ecdysone regulation of brain CK II activity are discussed.

  7. Acute and chronic changes in brain activity with deep brain stimulation for refractory depression.

    Science.gov (United States)

    Conen, Silke; Matthews, Julian C; Patel, Nikunj K; Anton-Rodriguez, José; Talbot, Peter S

    2018-04-01

    Deep brain stimulation is a potential option for patients with treatment-refractory depression. Deep brain stimulation benefits have been reported when targeting either the subgenual cingulate or ventral anterior capsule/nucleus accumbens. However, not all patients respond and optimum stimulation-site is uncertain. We compared deep brain stimulation of the subgenual cingulate and ventral anterior capsule/nucleus accumbens separately and combined in the same seven treatment-refractory depression patients, and investigated regional cerebral blood flow changes associated with acute and chronic deep brain stimulation. Deep brain stimulation-response was defined as reduction in Montgomery-Asberg Depression Rating Scale score from baseline of ≥50%, and remission as a Montgomery-Asberg Depression Rating Scale score ≤8. Changes in regional cerebral blood flow were assessed using [ 15 O]water positron emission tomography. Remitters had higher relative regional cerebral blood flow in the prefrontal cortex at baseline and all subsequent time-points compared to non-remitters and non-responders, with prefrontal cortex regional cerebral blood flow generally increasing with chronic deep brain stimulation. These effects were consistent regardless of stimulation-site. Overall, no significant regional cerebral blood flow changes were apparent when deep brain stimulation was acutely interrupted. Deep brain stimulation improved treatment-refractory depression severity in the majority of patients, with consistent changes in local and distant brain regions regardless of target stimulation. Remission of depression was reached in patients with higher baseline prefrontal regional cerebral blood flow. Because of the small sample size these results are preliminary and further evaluation is necessary to determine whether prefrontal cortex regional cerebral blood flow could be a predictive biomarker of treatment response.

  8. Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography

    Science.gov (United States)

    Tian, Fenghua; Kozel, F. Andrew; Yennu, Amarnath; Croarkin, Paul E.; McClintock, Shawn M.; Mapes, Kimberly S.; Husain, Mustafa M.; Liu, Hanli

    2012-11-01

    Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (Δ[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the Δ[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.

  9. Time-Course Analysis of the Neuroanatomical Correlates of Sexual Arousal Evoked by Erotic Video Stimuli in Healthy Males

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, Thirunavukkarasu; Jeong, Gwang Woo; Kim, Tae Hoon; Kim, Gwang Won; Baek, Han Su; Kang, Heoung Keun [Chonnam National University Hospital, Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2010-06-15

    To assess the dynamic activations of the key brain areas associated with the time-course of the sexual arousal evoked by visual sexual stimuli in healthy male subjects. Fourteen right-handed heterosexual male volunteers participated in this study. Alternatively combined rest period and erotic video visual stimulation were used according to the standard block design. In order to illustrate and quantify the spatiotemporal activation patterns of the key brain regions, the activation period was divided into three different stages as the EARLY, MID and LATE stages. For the group result (p < 0.05), when comparing the MID stage with the EARLY stage, a significant increase of the brain activation was observed in the areas that included the inferior frontal gyrus, the supplementary motor area, the hippocampus, the head of the caudate nucleus, the midbrain, the superior occipital gyrus and the fusiform gyrus. At the same time, when comparing the EARLY stage with the MID stage, the putamen, the globus pallidus, the pons, the thalamus, the hypothalamus, the lingual gyrus and the cuneus yielded significantly increased activations. When comparing the LATE stage with the MID stage, all the above mentioned brain regions showed elevated activations except the hippocampus. Our results illustrate the spatiotemporal activation patterns of the key brain regions across the three stages of visual sexual arousal.

  10. Sustained Treatment with Insulin Detemir in Mice Alters Brain Activity and Locomotion.

    Directory of Open Access Journals (Sweden)

    Tina Sartorius

    <