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Sample records for ongoing cortical activity

  1. Hippocampal subfield and medial temporal cortical persistent activity during working memory reflects ongoing encoding

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    Rachel K Nauer

    2015-03-01

    Full Text Available Previous neuroimaging studies support a role for the medial temporal lobes (MTL in maintaining novel stimuli over brief working memory (WM delays, and suggest delay period activity predicts subsequent memory. Additionally, slice recording studies have demonstrated neuronal persistent spiking in entorhinal cortex (EC, perirhinal cortex (PrC, and hippocampus (CA1, CA3, subiculum. These data have led to computational models that suggest persistent spiking in parahippocampal regions could sustain neuronal representations of sensory information over many seconds. This mechanism may support both WM maintenance and encoding of information into long term episodic memory. The goal of the current study was to use high-resolution fMRI to elucidate the contributions of the MTL cortices and hippocampal subfields to WM maintenance as it relates to later episodic recognition memory. We scanned participants while they performed a delayed match to sample task with novel scene stimuli, and assessed their memory for these scenes post-scan. We hypothesized stimulus-driven activation that persists into the delay period—a putative correlate of persistent spiking—would predict later recognition memory. Our results suggest sample and delay period activation in the parahippocampal cortex (PHC, PrC, and subiculum (extending into DG/CA3 and CA1 was linearly related to increases in subsequent memory strength. These data extend previous neuroimaging studies that have constrained their analysis to either the sample or delay period by modeling these together as one continuous ongoing encoding process, and support computational frameworks that predict persistent activity underlies both WM and episodic encoding.

  2. Anisotropy of ongoing neural activity in the primate visual cortex

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    Maier A

    2014-09-01

    Full Text Available Alexander Maier,1 Michele A Cox,1 Kacie Dougherty,1 Brandon Moore,1 David A Leopold2 1Department of Psychology, College of Arts and Science, Vanderbilt University, Nashville, TN, USA; 2Section on Cognitive Neurophysiology and Imaging, National Institute of Mental Health, National Institute of Health, Bethesda, MD, USA Abstract: The mammalian neocortex features distinct anatomical variation in its tangential and radial extents. This review consolidates previously published findings from our group in order to compare and contrast the spatial profile of neural activity coherence across these distinct cortical dimensions. We focus on studies of ongoing local field potential (LFP data obtained simultaneously from multiple sites in the primary visual cortex in two types of experiments in which electrode contacts were spaced either along the cortical surface or at different laminar positions. These studies demonstrate that across both dimensions the coherence of ongoing LFP fluctuations diminishes as a function of interelectrode distance, although the nature and spatial scale of this falloff is very different. Along the cortical surface, the overall LFP coherence declines gradually and continuously away from a given position. In contrast, across the cortical layers, LFP coherence is discontinuous and compartmentalized as a function of depth. Specifically, regions of high LFP coherence fall into discrete superficial and deep laminar zones, with an abrupt discontinuity between the granular and infragranular layers. This spatial pattern of ongoing LFP coherence is similar when animals are at rest and when they are engaged in a behavioral task. These results point to the existence of partially segregated laminar zones of cortical processing that extend tangentially within the laminar compartments and are thus oriented orthogonal to the cortical columns. We interpret these electrophysiological observations in light of the known anatomical organization of

  3. INPRO: status, ongoing, activities and outlook

    International Nuclear Information System (INIS)

    Khoroshev, M.

    2004-01-01

    In this presentation author deals with activities of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). Presentation const of the following chapters: Introduction; Goals of INPRO and results of Phase IA; Basic principles, user requirements and methodology for assessment of INS; Highlights of INPRO in the areas of economics, environment, safety, waste management, proliferation resistance and infrastructure; Outlook Phase II of INPRO. It is concluded that INPRO has political, financial and technical support from Member States; Phase IA on the establishment of basic principles user requirements and criteria the development of an assessment methodology has been finalised; Phase IB addresses the validation of the INPRO methodology and the assessment of concepts and approaches; INPRO is open to all interested Member States an international organisations

  4. Sustainable Transportation Systems Research Group: Ongoing and Past Activities

    OpenAIRE

    Gkritza, Konstantina "Nadia"; Hurtado, Davis Chacon; Gkartzonikas, Christos; Ke, Yue; Losada, Lisa L

    2017-01-01

    This presentation describes the ongoing and past activities of the Sustainable Transportation Systems Research (STSR) group at Purdue University (https://engineering.purdue.edu/STSRG). The STSR group aims to achieve green, safe, efficient, and equitable transportation systems by studying and modeling transportation externalities, using state of the art statistical, econometric, and economic analysis tools.

  5. Ongoing spontaneous activity controls access to consciousness: a neuronal model for inattentional blindness.

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    Stanislas Dehaene

    2005-05-01

    Full Text Available Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden "ignition" of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of "inattentional blindness," in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness.

  6. Ongoing spontaneous activity controls access to consciousness: a neuronal model for inattentional blindness.

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    Dehaene, Stanislas; Changeux, Jean-Pierre

    2005-05-01

    Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden "ignition" of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of "inattentional blindness," in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness.

  7. Perceptual incongruence influences bistability and cortical activation.

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    Gijs Joost Brouwer

    Full Text Available We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry. Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict.

  8. Cortical activation in patients with functional hemispherectomy.

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    Leonhardt, G; Bingel, U; Spiekermann, G; Kurthen, M; Müller, S; Hufnagel, A

    2001-10-01

    Functional hemispherectomy, a safe and effective therapeutical procedure in medically intractable epilepsy, offers the chance to investigate a strictly unilateral cortical activation in ipsilateral limb movement. We assessed the pattern of cortical activation in a group of patients following functional hemispherectomy. We measured regional cerebral blood flow (rCBF) in 6 patients postoperatively and 6 normal subjects with positron emission tomography using 15[O]H2O as a tracer. Brain activation was achieved by passive elbow movements of the affected arm. Analysis of group results and between-group comparisons were performed with statistical parametric mapping, (SPM96). In normal subjects brain activation was found contralaterally in the cranial sensorimotor cortex and the supplementary motor area and ipsilaterally in the inferior parietal cortex. In patients significant rCBF increases were found in the inferior parietal cortex, caudal sensorimotor cortex and the supplementary motor area ipsilaterally. The activation was weaker than in normal subjects. Compared with normal subjects patients showed additional activation in the premotor cortex, caudal sensorimotor cortex and the inferior parietal cortex of the remaining hemisphere. Less activation compared with normal subjects was found in the cranial sensorimotor cortex and the supplementary motor area. A functional network connecting the inferior parietal cortex, premotor cortex and the supplementary motor area as well as the existence of ipsilateral projections originating from these regions may explain why these areas are predominantly involved in reorganization confined to a single hemisphere.

  9. Localization of cortical areas activated by thinking.

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    Roland, P E; Friberg, L

    1985-05-01

    These experiments were undertaken to demonstrate that pure mental activity, thinking, increases the cerebral blood flow and that different types of thinking increase the regional cerebral blood flow (rCBF) in different cortical areas. As a first approach, thinking was defined as brain work in the form of operations on internal information, done by an awake subject. The rCBF was measured in 254 cortical regions in 11 subjects with the intracarotid 133Xe injection technique. In normal man, changes in the regional cortical metabolic rate of O2 leads to proportional changes in rCBF. One control study was taken with the subjects at rest. Then the rCBF was measured during three different simple algorithm tasks, each consisting of retrieval of a specific memory followed by a simple operation on the retrieved information. Once started, the information processing went on in the brain without any communication with the outside world. In 50-3 thinking, the subjects started with 50 and then, in their minds only, continuously subtracted 3 from the result. In jingle thinking the subjects internally jumped every second word in a nine-word circular jingle. In route-finding thinking the subjects imagined that they started at their front door and then walked alternatively to the left or the right each time they reached a corner. The rCBF increased only in homotypical cortical areas during thinking. The areas in the superior prefrontal cortex increased their rCBF equivalently during the three types of thinking. In the remaining parts of the prefrontal cortex there were multifocal increases of rCBF. The localizations and intensities of these rCBF increases depended on the type of internal operation occurring. The rCBF increased bilaterally in the angular cortex during 50-3 thinking. The rCBF increased in the right midtemporal cortex exclusively during jingle thinking. The intermediate and remote visual association areas, the superior occipital, posterior inferior temporal, and

  10. Extraction and characterization of essential discharge patterns from multisite recordings of spiking ongoing activity.

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    Riccardo Storchi

    Full Text Available Neural activation patterns proceed often by schemes or motifs distributed across the involved cortical networks. As neurons are correlated, the estimate of all possible dependencies quickly goes out of control. The complex nesting of different oscillation frequencies and their high non-stationariety further hamper any quantitative evaluation of spiking network activities. The problem is exacerbated by the intrinsic variability of neural patterns.Our technique introduces two important novelties and enables to insulate essential patterns on larger sets of spiking neurons and brain activity regimes. First, the sampling procedure over N units is based on a fixed spike number k in order to detect N-dimensional arrays (k-sequences, whose sum over all dimension is k. Then k-sequences variability is greatly reduced by a hierarchical separative clustering, that assigns large amounts of distinct k-sequences to few classes. Iterative separations are stopped when the dimension of each cluster comes to be smaller than a certain threshold. As threshold tuning critically impacts on the number of classes extracted, we developed an effective cost criterion to select the shortest possible description of our dataset. Finally we described three indexes (C,S,R to evaluate the average pattern complexity, the structure of essential classes and their stability in time.We validated this algorithm with four kinds of surrogated activity, ranging from random to very regular patterned. Then we characterized a selection of ongoing activity recordings. By the S index we identified unstable, moderatly and strongly stable patterns while by the C and the R indices we evidenced their non-random structure. Our algorithm seems able to extract interesting and non-trivial spatial dynamics from multisource neuronal recordings of ongoing and potentially stimulated activity. Combined with time-frequency analysis of LFPs could provide a powerful multiscale approach linking population

  11. Stimuli reduce the dimensionality of cortical activity

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    Luca eMazzucato

    2016-02-01

    Full Text Available The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models.

  12. Stimuli Reduce the Dimensionality of Cortical Activity.

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    Mazzucato, Luca; Fontanini, Alfredo; La Camera, Giancarlo

    2016-01-01

    The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial) and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models.

  13. Localization of cortical areas activated by thinking

    DEFF Research Database (Denmark)

    Roland, P E; Friberg, L

    1985-01-01

    midtemporal cortex exclusively during jingle thinking. The intermediate and remote visual association areas, the superior occipital, posterior inferior temporal, and posterior superior parietal cortex, increased their rCBF exclusively during route-finding thinking. We observed no decreases in rCBF. All r......These experiments were undertaken to demonstrate that pure mental activity, thinking, increases the cerebral blood flow and that different types of thinking increase the regional cerebral blood flow (rCBF) in different cortical areas. As a first approach, thinking was defined as brain work...... communication with the outside world. In 50-3 thinking, the subjects started with 50 and then, in their minds only, continuously subtracted 3 from the result. In jingle thinking the subjects internally jumped every second word in a nine-word circular jingle. In route-finding thinking the subjects imagined...

  14. Jealousy increased by induced relative left frontal cortical activity.

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    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. (c) 2015 APA, all rights reserved).

  15. Cortical oscillatory activity during spatial echoic memory.

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    Kaiser, Jochen; Walker, Florian; Leiberg, Susanne; Lutzenberger, Werner

    2005-01-01

    In human magnetoencephalogram, we have found gamma-band activity (GBA), a putative measure of cortical network synchronization, during both bottom-up and top-down auditory processing. When sound positions had to be retained in short-term memory for 800 ms, enhanced GBA was detected over posterior parietal cortex, possibly reflecting the activation of higher sensory storage systems along the hypothesized auditory dorsal space processing stream. Additional prefrontal GBA increases suggested an involvement of central executive networks in stimulus maintenance. The present study assessed spatial echoic memory with the same stimuli but a shorter memorization interval of 200 ms. Statistical probability mapping revealed posterior parietal GBA increases at 80 Hz near the end of the memory phase and both gamma and theta enhancements in response to the test stimulus. In contrast to the previous short-term memory study, no prefrontal gamma or theta enhancements were detected. This suggests that spatial echoic memory is performed by networks along the putative auditory dorsal stream, without requiring an involvement of prefrontal executive regions.

  16. Perceptual incongruence influences bistability and cortical activation

    NARCIS (Netherlands)

    Brouwer, G.J.; Tong, F.; Hagoort, P.; van Ee, R.

    2009-01-01

    We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability

  17. Cortical Alpha Activity in Schizoaffective Patients.

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    Moeini, Mahdi; Khaleghi, Ali; Mohammadi, Mohammad Reza; Zarafshan, Hadi; Fazio, Rachel L; Majidi, Hamid

    2017-01-01

    Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT) receptor function in schizoaffective disorder (SA), a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA. Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) criteria for SA, and in 39 healthy controls. Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75) = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75) = 5.67, P = 0.025]. Conclusion : A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations.

  18. Amygdala activation for eye contact despite complete cortical blindness

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    Burra, N.; Hervais-Adelman, A.; Kerzel, D.; Tamietto, M.; de Gelder, B.; Pegna, A.J.

    2013-01-01

    Cortical blindness refers to the loss of vision that occurs after destruction of the primary visual cortex. Although there is no sensory cortex and hence no conscious vision, some cortically blind patients show amygdala activation in response to facial or bodily expressions of emotion. Here we

  19. Cortical activity in tinnitus patients and its modification by phonostimulation

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    Katarzyna Pawlak-Osińska

    2013-04-01

    Full Text Available OBJECTIVE: The goal of this study was to observe spontaneous cortical activity and cortical activity modulated by tinnitus-matched sound in tinnitus patients and healthy subjects with no otoneurologic symptoms. METHOD: Data were prospectively collected from 50 tinnitus patients and 25 healthy subjects. Cortical activity was recorded in all subjects with eyes closed and open and during photostimulation, hyperventilation and acoustic stimulation using 19-channel quantitative electroencephalography. The sound applied in the tinnitus patients was individually matched with the ability to mask or equal the tinnitus. The maximal and mean amplitude of the delta, theta, alpha and beta waves and the type and amount of the pathologic EEG patterns were noted during each recording. Differences in cortical localization and the influence of sound stimuli on spontaneous cortical activity were evaluated between the groups. RESULTS: The tinnitus group exhibited decreased delta activity and increased alpha and beta activity. Hyperventilation increased the intensity of the differences. The tinnitus patients had more sharp-slow waves and increased slow wave amplitude. Sound stimuli modified the EEG recordings; the delta and beta wave amplitudes were increased, whereas the alpha-1 wave amplitude was decreased. Acoustic stimulation only slightly affected the temporal region. CONCLUSION: Cortical activity in the tinnitus patients clearly differed from that in healthy subjects, i.e., tinnitus is not a “phantom” sign. The changes in cortical activity included decreased delta wave amplitudes, increased alpha-1, beta-1 and beta-h wave amplitudes and pathologic patterns. Cortical activity modifications occurred predominantly in the temporal region. Acoustic stimulation affected spontaneous cortical activity only in tinnitus patients, and although the applied sound was individually matched, the pathologic changes were only slightly improved.

  20. Basal Forebrain Gating by Somatostatin Neurons Drives Prefrontal Cortical Activity.

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    Espinosa, Nelson; Alonso, Alejandra; Morales, Cristian; Espinosa, Pedro; Chávez, Andrés E; Fuentealba, Pablo

    2017-11-17

    The basal forebrain provides modulatory input to the cortex regulating brain states and cognitive processing. Somatostatin-expressing neurons constitute a heterogeneous GABAergic population known to functionally inhibit basal forebrain cortically projecting cells thus favoring sleep and cortical synchronization. However, it remains unclear if somatostatin cells can regulate population activity patterns in the basal forebrain and modulate cortical dynamics. Here, we demonstrate that somatostatin neurons regulate the corticopetal synaptic output of the basal forebrain impinging on cortical activity and behavior. Optogenetic inactivation of somatostatin neurons in vivo rapidly modified neural activity in the basal forebrain, with the consequent enhancement and desynchronization of activity in the prefrontal cortex, reflected in both neuronal spiking and network oscillations. Cortical activation was partially dependent on cholinergic transmission, suppressing slow waves and potentiating gamma oscillations. In addition, recruitment dynamics was cell type-specific, with interneurons showing similar temporal profiles, but stronger responses than pyramidal cells. Finally, optogenetic stimulation of quiescent animals during resting periods prompted locomotor activity, suggesting generalized cortical activation and increased arousal. Altogether, we provide physiological and behavioral evidence indicating that somatostatin neurons are pivotal in gating the synaptic output of the basal forebrain, thus indirectly controlling cortical operations via both cholinergic and non-cholinergic mechanisms. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Early development of synchrony in cortical activations in the human.

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    Koolen, N; Dereymaeker, A; Räsänen, O; Jansen, K; Vervisch, J; Matic, V; Naulaers, G; De Vos, M; Van Huffel, S; Vanhatalo, S

    2016-05-13

    Early intermittent cortical activity is thought to play a crucial role in the growth of neuronal network development, and large scale brain networks are known to provide the basis for higher brain functions. Yet, the early development of the large scale synchrony in cortical activations is unknown. Here, we tested the hypothesis that the early intermittent cortical activations seen in the human scalp EEG show a clear developmental course during the last trimester of pregnancy, the period of intensive growth of cortico-cortical connections. We recorded scalp EEG from altogether 22 premature infants at post-menstrual age between 30 and 44 weeks, and the early cortical synchrony was quantified using recently introduced activation synchrony index (ASI). The developmental correlations of ASI were computed for individual EEG signals as well as anatomically and mathematically defined spatial subgroups. We report two main findings. First, we observed a robust and statistically significant increase in ASI in all cortical areas. Second, there were significant spatial gradients in the synchrony in fronto-occipital and left-to-right directions. These findings provide evidence that early cortical activity is increasingly synchronized across the neocortex. The ASI-based metrics introduced in our work allow direct translational comparison to in vivo animal models, as well as hold promise for implementation as a functional developmental biomarker in future research on human neonates. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. The relation of ongoing brain activity, evoked neural responses, and cognition

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    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. Flow of cortical activity underlying a tactile decision in mice

    OpenAIRE

    Guo, Zengcai V.; Li, Nuo; Huber, Daniel; Ophir, Eran; Gutnisky, Diego; Ting, Jonathan T.; Feng, Guoping; Svoboda, Karel

    2013-01-01

    Perceptual decisions involve distributed cortical activity. Does information flow sequentially from one cortical area to another, or do networks of interconnected areas contribute at the same time? Here we delineate when and how activity in specific areas drives a whisker-based decision in mice. A short-term memory component temporally separated tactile “sensation” and “action” (licking). Using optogenetic inhibition (spatial resolution, 2 mm; temporal resolution, 100 ms), we surveyed the neo...

  4. Functional MRI study of cerebral cortical activation during volitional swallowing

    International Nuclear Information System (INIS)

    Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji

    2002-01-01

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  5. Functional MRI study of cerebral cortical activation during volitional swallowing

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    Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji [Okayama Univ. (Japan). Graduate School of Medicine and Dentistry

    2002-12-01

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  6. Time course of ongoing activity during neuritis and following axonal transport disruption.

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    Satkeviciute, Ieva; Goodwin, George; Bove, Geoffrey M; Dilley, Andrew

    2018-05-01

    Local nerve inflammation (neuritis) leads to ongoing activity and axonal mechanical sensitivity (AMS) along intact nociceptor axons and disrupts axonal transport. This phenomenon forms the most feasible cause of radiating pain, such as sciatica. We have previously shown that axonal transport disruption without inflammation or degeneration also leads to AMS but does not cause ongoing activity at the time point when AMS occurs, despite causing cutaneous hypersensitivity. However, there have been no systematic studies of ongoing activity during neuritis or noninflammatory axonal transport disruption. In this study, we present the time course of ongoing activity from primary sensory neurons following neuritis and vinblastine-induced axonal transport disruption. Whereas 24% of C/slow Aδ-fiber neurons had ongoing activity during neuritis, few (disruption of axonal transport without inflammation does not lead to ongoing activity in sensory neurons, including nociceptors, but does cause a rapid and transient development of AMS. Because it is proposed that AMS underlies mechanically induced radiating pain, and a transient disruption of axonal transport (as previously reported) leads to transient AMS, it follows that processes that disrupt axonal transport, such as neuritis, must persist to maintain AMS and the associated symptoms. NEW & NOTEWORTHY Many patients with radiating pain lack signs of nerve injury on clinical examination but may have neuritis, which disrupts axonal transport. We have shown that axonal transport disruption does not induce ongoing activity in primary sensory neurons but does cause transient axonal mechanical sensitivity. The present data complete a profile of key axonal sensitivities following axonal transport disruption. Collectively, this profile supports that an active peripheral process is necessary for maintained axonal sensitivities.

  7. Glycine Receptor α2 Subunit Activation Promotes Cortical Interneuron Migration

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    Ariel Avila

    2013-08-01

    Full Text Available Glycine receptors (GlyRs are detected in the developing CNS before synaptogenesis, but their function remains elusive. This study demonstrates that functional GlyRs are expressed by embryonic cortical interneurons in vivo. Furthermore, genetic disruption of these receptors leads to interneuron migration defects. We discovered that extrasynaptic activation of GlyRs containing the α2 subunit in cortical interneurons by endogenous glycine activates voltage-gated calcium channels and promotes calcium influx, which further modulates actomyosin contractility to fine-tune nuclear translocation during migration. Taken together, our data highlight the molecular events triggered by GlyR α2 activation that control cortical tangential migration during embryogenesis.

  8. Stereotypic wheel running decreases cortical activity in mice

    Science.gov (United States)

    Fisher, Simon P.; Cui, Nanyi; McKillop, Laura E.; Gemignani, Jessica; Bannerman, David M.; Oliver, Peter L.; Peirson, Stuart N.; Vyazovskiy, Vladyslav V.

    2016-01-01

    Prolonged wakefulness is thought to gradually increase ‘sleep need' and influence subsequent sleep duration and intensity, but the role of specific waking behaviours remains unclear. Here we report the effect of voluntary wheel running during wakefulness on neuronal activity in the motor and somatosensory cortex in mice. We find that stereotypic wheel running is associated with a substantial reduction in firing rates among a large subpopulation of cortical neurons, especially at high speeds. Wheel running also has longer-term effects on spiking activity across periods of wakefulness. Specifically, cortical firing rates are significantly higher towards the end of a spontaneous prolonged waking period. However, this increase is abolished when wakefulness is dominated by running wheel activity. These findings indicate that wake-related changes in firing rates are determined not only by wake duration, but also by specific waking behaviours. PMID:27748455

  9. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons.

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    Hyeon Seo

    Full Text Available Subdural cortical stimulation (SuCS is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5 that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information.

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

    DEFF Research Database (Denmark)

    Lassen, N A; Larsen, B

    1980-01-01

    of cortical activity seen during various language functions, emphasizing the practically symmetrical involvement in both hemispheres. A case of auditive agnosia (with complete cortical word deafness but preserved pure tone thresholds) is presented. The patient's normal speech constitutes evidence...

  11. Prominent microglial activation in cortical white matter is selectively associated with cortical atrophy in primary progressive aphasia.

    Science.gov (United States)

    Ohm, Daniel T; Kim, Garam; Gefen, Tamar; Rademaker, Alfred; Weintraub, Sandra; Bigio, Eileen; Mesulam, M-Marsel; Rogalski, Emily; Geula, Changiz

    2018-04-21

    Primary progressive aphasia (PPA) is a clinical syndrome characterized by selective language impairments associated with focal cortical atrophy favouring the language dominant hemisphere. PPA is associated with Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD), and significant accumulation of activated microglia. Activated microglia can initiate an inflammatory cascade that may contribute to neurodegeneration, but their quantitative distribution in cortical white matter and their relationship with cortical atrophy are unknown. We investigated white matter activated microglia and their association with grey matter atrophy in 10 PPA cases with either AD or FTLD-TDP pathology. Activated microglia were quantified with optical density measures of HLA-DR immunoreactivity in two regions with peak cortical atrophy, and one non-atrophied region within the language dominant hemisphere of each PPA case. Non-atrophied contralateral homologues of the language dominant regions were examined for hemispheric asymmetry. Qualitatively, greater densities of activated microglia were observed in cortical white matter when compared to grey matter. Quantitative analyses revealed significantly greater densities of activated microglia in the white matter of atrophied regions compared to non-atrophied regions in the language dominant hemisphere (p<0.05). Atrophied regions of the language dominant hemisphere also showed significantly more activated microglia compared to contralateral homologues (p<0.05). White matter activated microglia accumulate more in atrophied regions in the language dominant hemisphere of PPA. While microglial activation may constitute a response to neurodegenerative processes in white matter, the resultant inflammatory processes may also exacerbate disease progression and contribute to cortical atrophy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Abstract Art and Cortical Motor Activation: an EEG study.

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    Maria Alessandra eUmilta'

    2012-11-01

    Full Text Available The role of the motor system in the perception of visual art remains to be better understood. Earlier studies on the visual perception of abstract art (from Gestalt theory, as in Arnheim 1954 and 1988, to balance preference studies as in Locher and Stappers, 2002, and more recent work by Locher et al 2007, Redies, 2007, and Taylor et al, 2011, neglected the question, while the field of neuroesthetics (Zeki, 1999; Ramachandran and Hirstein, 1999 mostly concentrated on figurative works. Much recent work has demonstrated the multimodality of vision, encompassing the activation of motor, somatosensory and viscero-motor brain regions. The present study investigated whether the observation of high-resolution digitized static images of abstract paintings by Lucio Fontana is associated with specific cortical motor activation in the beholder’s brain. Mu rhythm suppression was evoked by the observation of original art works but not by control stimuli (as in the case of graphically modified versions of these works. Most interestingly, previous visual exposure to the stimuli did not affect the mu rhythm suppression induced by their observation. The present results clearly show the involvement of the cortical motor system in the viewing of static abstract art works.

  13. STOP-EVENT-RELATED POTENTIALS FROM INTRACRANIAL ELECTRODES REVEAL A KEY ROLE OF PREMOTOR AND MOTOR CORTICES IN STOPPING ONGOING MOVEMENTS

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    Maurizio eMattia

    2012-06-01

    Full Text Available In humans, the ability to withhold manual motor responses seems to rely on a right-lateralized frontal–basal ganglia–thalamic network, including the pre-supplementary motor area and the inferior frontal gyrus. These areas should drive subthalamic nuclei to implement movement inhibition via the hyperdirect pathway. The output of this network is expected to influence those cortical areas underlying limb movement preparation and initiation, i.e. premotor (PMA and primary motor (M1 cortices. Electroencephalographic (EEG studies have shown an enhancement of the N200/P300 complex in the event-related potentials (ERPs when a planned reaching movement is successfully stopped after the presentation of an infrequent stop-signal. PMA and M1 have been suggested as possible neural sources of this ERP complex but, due to the limited spatial resolution of scalp EEG, it is not yet clear which cortical areas contribute to its generation. To elucidate the role of motor cortices, we recorded epicortical ERPs from the lateral surface of the fronto-temporal lobes of five pharmacoresistant epileptic patients performing a reaching version of the countermanding task while undergoing presurgical monitoring. We consistently found a stereotyped ERP complex on a single-trial level when a movement was successfully cancelled. These ERPs were selectively expressed in M1, PMA and Brodmann's area (BA 9 and their onsets preceded the end of the stop process, suggesting a causal involvement in this executive function. Such ERPs also occurred in unsuccessful-stop trials, that is, when subjects moved despite the occurrence of a stop-signal, mostly when they had long reaction times. These findings support the hypothesis that motor cortices are the final target of the inhibitory command elaborated by the frontal–basal ganglia–thalamic network.

  14. No effect of mercury exposure on kidney function during ongoing artisanal gold mining activities in Colombia.

    Science.gov (United States)

    Rodríguez, Luz Helena Sánchez; Rodríguez-Villamizar, Laura Andrea; Flórez-Vargas, Oscar; Fiallo, Yolanda Vargas; Ordoñez, Álvaro; Gutiérrez, Myriam Del Carmen

    2017-01-01

    This cross-sectional study examined whether people who are exposed to mercury (Hg) vapours in ongoing artisanal gold mining activities have alteration in kidney function monitoring parameters. The study enrolled 164 miners and 127 participant controls. The Hg concentrations for miners and control participants were measured in blood (B-Hg; median 7.0 vs. 2.5 µg/L), urine (U-Hg; median 3.9 vs. 1.5 µg/g creatinine) and hair (H-Hg; median 0.8 vs. 0.4 µg/g hair). The biomarkers of renal function were creatinine, albumin and excretion of β-2 microglobulin. Glomerular filtration rate (eGFR) was calculated using the chronic kidney disease epidemiology collaboration equation. Significant statistical differences were found in Hg concentrations and eGFR levels between the two study groups ( p association was found between the prevalence of reduced eGFR (associated with Hg vapour exposure in ongoing artisanal gold mining, whose population has a level of Hg exposure from low to moderate (B-Hg from 3.4 to 11.0 µg/L and U-Hg from 1.3 to 9.6 µg/g creatinine).

  15. Functional localization and effective connectivity of cortical theta and alpha oscillatory activity during an attention task

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    Yuichi Kitaura

    detailed level, decreased flow from right inferior frontal gyrus to anterior cingulate cortex for theta, and low and high alpha oscillations, and increased feedback (bidirectional flow between left superior temporal gyrus and left inferior frontal gyrus, were observed during the arithmetic task. Conclusions: Task related medial prefrontal increase in theta oscillations possibly corresponds to frontal midline theta, while parietal decreased alpha1 activity indicates the active role of this region in the numerical task. Task related decrease of intracortical right hemispheric connectivity support the notion that these nodes need to disengage from one another in order to not interfere with the ongoing numerical processing. The bidirectional feedback between left frontal-temporal-parietal regions in the arithmetic task is very likely to be related to attention network working memory function. Significance: The methods of analysis and the results presented here will hopefully contribute to clarify the roles of the different EEG oscillations during sustained attention, both in terms of their functional localization and in terms of how they integrate brain function by supporting information flow between different cortical regions. The methodology presented here might be clinically relevant in evaluating abnormal attention function. Keywords: Quantitative EEG, sLORETA, iCoh, Directional connectivity, Frontal midline theta, Attention network, Mental arithmetic, Fronto-parietal network, Directional flow, Attention task, Granger causality

  16. Natural Translating Locomotion Modulates Cortical Activity at Action Observation

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    Thierry Pozzo

    2017-11-01

    Full Text Available The present study verified if the translational component of locomotion modulated cortical activity recorded at action observation. Previous studies focusing on visual processing of biological motion mainly presented point light walker that were fixed on a spot, thus removing the net translation toward a goal that yet remains a critical feature of locomotor behavior. We hypothesized that if biological motion recognition relies on the transformation of seeing in doing and its expected sensory consequences, a significant effect of translation compared to centered displays on sensorimotor cortical activity is expected. To this aim, we explored whether EEG activity in the theta (4–8 Hz, alpha (8–12 Hz, beta 1 (14–20 Hz and beta 2 (20–32 Hz frequency bands exhibited selectivity as participants viewed four types of stimuli: a centered walker, a centered scrambled, a translating walker and a translating scrambled. We found higher theta synchronizations for observed stimulus with familiar shape. Higher power decreases in the beta 1 and beta 2 bands, indicating a stronger motor resonance was elicited by translating compared to centered stimuli. Finally, beta bands modulation in Superior Parietal areas showed that the translational component of locomotion induced greater motor resonance than human shape. Using a Multinomial Logistic Regression classifier we found that Dorsal-Parietal and Inferior-Frontal regions of interest (ROIs, constituting the core of action-observation system, were the only areas capable to discriminate all the four conditions, as reflected by beta activities. Our findings suggest that the embodiment elicited by an observed scenario is strongly mediated by horizontal body displacement.

  17. Cortical language activation in aphasia: a functional MRI study

    International Nuclear Information System (INIS)

    Xu Xiaojun; Zhang Minming; Shang Desheng; Wang Qidong; Luo Benyan

    2004-01-01

    Objective: To investigate the differences of the underlying neural basis of language processing between normal subjects and aphasics, and to study the feasibility for functional magnetic resonance imaging (fMRI) in examining the cortical language activation in clinical aphasics. Methods: fMRI was used to map language network in 6 normal subjects and 3 patients with aphasia who were in the stage of recovery from acute stroke. The participants performed word generation task during fMRI scanning, which measured the signal changes associated with regional neural activity induced by the task. These signal changes were processed to statistically generate the activation map that represented the language area. Results: In normal subjects, a distributed language network was activated. Activations were present in the frontal, temporal, parietal and occipital regions in normal group. In the patient group, however, no activation was showed in the left inferior frontal gyrus whether or not the patient had lesion in the left frontal lobe. Two patients showed activations in some right hemisphere regions where no activation appeared in normal subjects. Conclusion: The remote effect of focal lesion and functional redistribution or reorganization was found in aphasic patients. fMRI was useful in evaluating the language function in aphasic patients. (authors)

  18. Impairment of GABA transporter GAT-1 terminates cortical recurrent network activity via enhanced phasic inhibition

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    Daniel Simon Razik

    2013-09-01

    Full Text Available In the central nervous system, GABA transporters (GATs very efficiently clear synaptically released GABA from the extracellular space, and thus exert a tight control on GABAergic inhibition. In neocortex, GABAergic inhibition is heavily recruited during recurrent phases of spontaneous action potential activity which alternate with neuronally quiet periods. Therefore, such activity should be quite sensitive to minute alterations of GAT function. Here, we explored the effects of a gradual impairment of GAT-1 and GAT-2/3 on spontaneous recurrent network activity – termed network bursts and silent periods – in organotypic slice cultures of rat neocortex. The GAT-1 specific antagonist NO-711 depressed activity already at nanomolar concentrations (IC50 for depression of spontaneous multiunit firing rate of 42 nM, reaching a level of 80% at 500-1000 nM. By contrast, the GAT-2/3 preferring antagonist SNAP-5114 had weaker and less consistent effects. Several lines of evidence pointed towards an enhancement of phasic GABAergic inhibition as the dominant activity-depressing mechanism: network bursts were drastically shortened, phasic GABAergic currents decayed slower, and neuronal excitability during ongoing activity was diminished. In silent periods, NO-711 had little effect on neuronal excitability or membrane resistance, quite in contrast to the effects of muscimol, a GABA mimetic which activates GABAA receptors tonically. Our results suggest that an enhancement of phasic GABAergic inhibition efficiently curtails cortical recurrent activity and may mediate antiepileptic effects of therapeutically relevant concentrations of GAT-1 antagonists.

  19. Exercising self-control increases relative left frontal cortical activation.

    Science.gov (United States)

    Schmeichel, Brandon J; Crowell, Adrienne; Harmon-Jones, Eddie

    2016-02-01

    Self-control refers to the capacity to override or alter a predominant response tendency. The current experiment tested the hypothesis that exercising self-control temporarily increases approach motivation, as revealed by patterns of electrical activity in the prefrontal cortex. Participants completed a writing task that did vs did not require them to exercise self-control. Then they viewed pictures known to evoke positive, negative or neutral affect. We assessed electroencephalographic (EEG) activity while participants viewed the pictures, and participants reported their trait levels of behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivity at the end of the study. We found that exercising (vs not exercising) self-control increased relative left frontal cortical activity during picture viewing, particularly among individuals with relatively higher BAS than BIS, and particularly during positive picture viewing. A similar but weaker pattern emerged during negative picture viewing. The results suggest that exercising self-control temporarily increases approach motivation, which may help to explain the aftereffects of self-control (i.e. ego depletion). © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  20. 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.

  1. Prognostic value of cortically induced motor evoked activity by TMS in chronic stroke: Caveats from a revealing single clinical case

    Directory of Open Access Journals (Sweden)

    Amengual Julià L

    2012-06-01

    Full Text Available Abstract Background We 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 presentation Multimodal 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. Conclusions The 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.

  2. Modeling vocalization with ECoG cortical activity recorded during vocal production in the macaque monkey.

    Science.gov (United States)

    Fukushima, Makoto; Saunders, Richard C; Fujii, Naotaka; Averbeck, Bruno B; Mishkin, Mortimer

    2014-01-01

    Vocal production is an example of controlled motor behavior with high temporal precision. Previous studies have decoded auditory evoked cortical activity while monkeys listened to vocalization sounds. On the other hand, there have been few attempts at decoding motor cortical activity during vocal production. Here we recorded cortical activity during vocal production in the macaque with a chronically implanted electrocorticographic (ECoG) electrode array. The array detected robust activity in motor cortex during vocal production. We used a nonlinear dynamical model of the vocal organ to reduce the dimensionality of `Coo' calls produced by the monkey. We then used linear regression to evaluate the information in motor cortical activity for this reduced representation of calls. This simple linear model accounted for circa 65% of the variance in the reduced sound representations, supporting the feasibility of using the dynamical model of the vocal organ for decoding motor cortical activity during vocal production.

  3. Active learning of cortical connectivity from two-photon imaging data

    Science.gov (United States)

    Wang, Ye; Dunson, David; Sapiro, Guillermo; Ringach, Dario

    2018-01-01

    Understanding how groups of neurons interact within a network is a fundamental question in system neuroscience. Instead of passively observing the ongoing activity of a network, we can typically perturb its activity, either by external sensory stimulation or directly via techniques such as two-photon optogenetics. A natural question is how to use such perturbations to identify the connectivity of the network efficiently. Here we introduce a method to infer sparse connectivity graphs from in-vivo, two-photon imaging of population activity in response to external stimuli. A novel aspect of the work is the introduction of a recommended distribution, incrementally learned from the data, to optimally refine the inferred network. Unlike existing system identification techniques, this “active learning” method automatically focuses its attention on key undiscovered areas of the network, instead of targeting global uncertainty indicators like parameter variance. We show how active learning leads to faster inference while, at the same time, provides confidence intervals for the network parameters. We present simulations on artificial small-world networks to validate the methods and apply the method to real data. Analysis of frequency of motifs recovered show that cortical networks are consistent with a small-world topology model. PMID:29718955

  4. Active learning of cortical connectivity from two-photon imaging data.

    Directory of Open Access Journals (Sweden)

    Martín A Bertrán

    Full Text Available Understanding how groups of neurons interact within a network is a fundamental question in system neuroscience. Instead of passively observing the ongoing activity of a network, we can typically perturb its activity, either by external sensory stimulation or directly via techniques such as two-photon optogenetics. A natural question is how to use such perturbations to identify the connectivity of the network efficiently. Here we introduce a method to infer sparse connectivity graphs from in-vivo, two-photon imaging of population activity in response to external stimuli. A novel aspect of the work is the introduction of a recommended distribution, incrementally learned from the data, to optimally refine the inferred network. Unlike existing system identification techniques, this "active learning" method automatically focuses its attention on key undiscovered areas of the network, instead of targeting global uncertainty indicators like parameter variance. We show how active learning leads to faster inference while, at the same time, provides confidence intervals for the network parameters. We present simulations on artificial small-world networks to validate the methods and apply the method to real data. Analysis of frequency of motifs recovered show that cortical networks are consistent with a small-world topology model.

  5. The role of asymmetric frontal cortical activity in emotion-related phenomena: a review and update.

    Science.gov (United States)

    Harmon-Jones, Eddie; Gable, Philip A; Peterson, Carly K

    2010-07-01

    Conceptual and empirical approaches to the study of the role of asymmetric frontal cortical activity in emotional processes are reviewed. Although early research suggested that greater left than right frontal cortical activity was associated with positive affect, more recent research, primarily on anger, suggests that greater left than right frontal cortical activity is associated with approach motivation, which can be positive (e.g., enthusiasm) or negative in valence (e.g., anger). In addition to reviewing this research on anger, research on guilt, bipolar disorder, and various types of positive affect is reviewed with relation to their association with asymmetric frontal cortical activity. The reviewed research not only contributes to a more complete understanding of the emotive functions of asymmetric frontal cortical activity, but it also points to the importance of considering motivational direction as separate from affective valence in psychological models of emotional space. Copyright © 2009 Elsevier B.V. All rights reserved.

  6. Effects of Parecoxib and Fentanyl on nociception-induced cortical activity

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    Wang Ying-Wei

    2010-01-01

    Full Text Available Abstract Background Analgesics, including opioids and non-steroid anti-inflammatory drugs reduce postoperative pain. However, little is known about the quantitative effects of these drugs on cortical activity induced by nociceptive stimulation. The aim of the present study was to determine the neural activity in response to a nociceptive stimulus and to investigate the effects of fentanyl (an opioid agonist and parecoxib (a selective cyclooxygenase-2 inhibitor on this nociception-induced cortical activity evoked by tail pinch. Extracellular recordings (electroencephalogram and multi-unit signals were performed in the area of the anterior cingulate cortex while intracellular recordings were made in the primary somatosensory cortex. The effects of parecoxib and fentanyl on induced cortical activity were compared. Results Peripheral nociceptive stimulation in anesthetized rats produced an immediate electroencephalogram (EEG desynchronization resembling the cortical arousal (low-amplitude, fast-wave activity, while the membrane potential switched into a persistent depolarization state. The induced cortical activity was abolished by fentanyl, and the fentanyl's effect was reversed by the opioid receptor antagonist, naloxone. Parecoxib, on the other hand, did not significantly affect the neural activity. Conclusion Cortical activity was modulated by nociceptive stimulation in anesthetized rats. Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

  7. Human temporal cortical single neuron activity during working memory maintenance.

    Science.gov (United States)

    Zamora, Leona; Corina, David; Ojemann, George

    2016-06-01

    The Working Memory model of human memory, first introduced by Baddeley and Hitch (1974), has been one of the most influential psychological constructs in cognitive psychology and human neuroscience. However the neuronal correlates of core components of this model have yet to be fully elucidated. Here we present data from two studies where human temporal cortical single neuron activity was recorded during tasks differentially affecting the maintenance component of verbal working memory. In Study One we vary the presence or absence of distracting items for the entire period of memory storage. In Study Two we vary the duration of storage so that distractors filled all, or only one-third of the time the memory was stored. Extracellular single neuron recordings were obtained from 36 subjects undergoing awake temporal lobe resections for epilepsy, 25 in Study one, 11 in Study two. Recordings were obtained from a total of 166 lateral temporal cortex neurons during performance of one of these two tasks, 86 study one, 80 study two. Significant changes in activity with distractor manipulation were present in 74 of these neurons (45%), 38 Study one, 36 Study two. In 48 (65%) of those there was increased activity during the period when distracting items were absent, 26 Study One, 22 Study Two. The magnitude of this increase was greater for Study One, 47.6%, than Study Two, 8.1%, paralleling the reduction in memory errors in the absence of distracters, for Study One of 70.3%, Study Two 26.3% These findings establish that human lateral temporal cortex is part of the neural system for working memory, with activity during maintenance of that memory that parallels performance, suggesting it represents active rehearsal. In 31 of these neurons (65%) this activity was an extension of that during working memory encoding that differed significantly from the neural processes recorded during overt and silent language tasks without a recent memory component, 17 Study one, 14 Study two

  8. Human Temporal Cortical Single Neuron Activity During Working Memory Maintenance

    Science.gov (United States)

    Zamora, Leona; Corina, David; Ojemann, George

    2016-01-01

    The Working Memory model of human memory, first introduced by Baddeley and Hitch (1974), has been one of the most influential psychological constructs in cognitive psychology and human neuroscience. However the neuronal correlates of core components of this model have yet to be fully elucidated. Here we present data from two studies where human temporal cortical single neuron activity was recorded during tasks differentially affecting the maintenance component of verbal working memory. In Study One we vary the presence or absence of distracting items for the entire period of memory storage. In Study Two we vary the duration of storage so that distractors filled all, or only one-third of the time the memory was stored. Extracellular single neuron recordings were obtained from 36 subjects undergoing awake temporal lobe resections for epilepsy, 25 in Study one, 11 in Study two. Recordings were obtained from a total of 166 lateral temporal cortex neurons during performance of one of these two tasks, 86 study one, 80 study two. Significant changes in activity with distractor manipulation were present in 74 of these neurons (45%), 38 Study one, 36 Study two. In 48 (65%) of those there was increased activity during the period when distracting items were absent, 26 Study One, 22 Study Two. The magnitude of this increase was greater for Study One, 47.6%, than Study Two, 8.1%, paralleling the reduction in memory errors in the absence of distracters, for Study One of 70.3%, Study Two 26.3% These findings establish that human lateral temporal cortex is part of the neural system for working memory, with activity during maintenance of that memory that parallels performance, suggesting it represents active rehearsal. In 31 of these neurons (65%) this activity was an extension of that during working memory encoding that differed significantly from the neural processes recorded during overt and silent language tasks without a recent memory component, 17 Study one, 14 Study two

  9. Stochastic modeling of neurobiological time series: Power, coherence, Granger causality, and separation of evoked responses from ongoing activity

    Science.gov (United States)

    Chen, Yonghong; Bressler, Steven L.; Knuth, Kevin H.; Truccolo, Wilson A.; Ding, Mingzhou

    2006-06-01

    In this article we consider the stochastic modeling of neurobiological time series from cognitive experiments. Our starting point is the variable-signal-plus-ongoing-activity model. From this model a differentially variable component analysis strategy is developed from a Bayesian perspective to estimate event-related signals on a single trial basis. After subtracting out the event-related signal from recorded single trial time series, the residual ongoing activity is treated as a piecewise stationary stochastic process and analyzed by an adaptive multivariate autoregressive modeling strategy which yields power, coherence, and Granger causality spectra. Results from applying these methods to local field potential recordings from monkeys performing cognitive tasks are presented.

  10. Brain activation in motor sequence learning is related to the level of native cortical excitability.

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    Silke Lissek

    Full Text Available Cortical excitability may be subject to changes through training and learning. Motor training can increase cortical excitability in motor cortex, and facilitation of motor cortical excitability has been shown to be positively correlated with improvements in performance in simple motor tasks. Thus cortical excitability may tentatively be considered as a marker of learning and use-dependent plasticity. Previous studies focused on changes in cortical excitability brought about by learning processes, however, the relation between native levels of cortical excitability on the one hand and brain activation and behavioral parameters on the other is as yet unknown. In the present study we investigated the role of differential native motor cortical excitability for learning a motor sequencing task with regard to post-training changes in excitability, behavioral performance and involvement of brain regions. Our motor task required our participants to reproduce and improvise over a pre-learned motor sequence. Over both task conditions, participants with low cortical excitability (CElo showed significantly higher BOLD activation in task-relevant brain regions than participants with high cortical excitability (CEhi. In contrast, CElo and CEhi groups did not exhibit differences in percentage of correct responses and improvisation level. Moreover, cortical excitability did not change significantly after learning and training in either group, with the exception of a significant decrease in facilitatory excitability in the CEhi group. The present data suggest that the native, unmanipulated level of cortical excitability is related to brain activation intensity, but not to performance quality. The higher BOLD mean signal intensity during the motor task might reflect a compensatory mechanism in CElo participants.

  11. Knowledge about Sounds – Context-Specific Meaning Differently Activates Cortical Hemispheres, Auditory Cortical Fields and Layers in House Mice

    Directory of Open Access Journals (Sweden)

    Diana B. Geissler

    2016-03-01

    Full Text Available Activation of the auditory cortex (AC by a given sound pattern is plastic, depending, in largely unknown ways, on the physiological state and the behavioral context of the receiving animal and on the receiver's experience with the sounds. Such plasticity can be inferred when house mouse mothers respond maternally to pup ultrasounds right after parturition and naïve females have to learn to respond. Here we use c-FOS immunocytochemistry to quantify highly activated neurons in the AC fields and layers of seven groups of mothers and naïve females who have different knowledge about and are differently motivated to respond to acoustic models of pup ultrasounds of different behavioral significance. Profiles of FOS-positive cells in the AC primary fields (AI, AAF, the ultrasonic field (UF, the secondary field (AII, and the dorsoposterior field (DP suggest that activation reflects in AI, AAF, and UF the integration of sound properties with animal state-dependent factors, in the higher-order field AII the news value of a given sound in the behavioral context, and in the higher-order field DP the level of maternal motivation and, by left-hemisphere activation advantage, the recognition of the meaning of sounds in the given context. Anesthesia reduced activation in all fields, especially in cortical layers 2/3. Thus, plasticity in the AC is field-specific preparing different output of AC fields in the process of perception, recognition and responding to communication sounds. Further, the activation profiles of the auditory cortical fields suggest the differentiation between brains hormonally primed to know (mothers and brains which acquired knowledge via implicit learning (naïve females. In this way, auditory cortical activation discriminates between instinctive (mothers and learned (naïve females cognition.

  12. Management of Ground and Groundwater Contamination on a Compact Site Constrained by Ongoing Activities

    International Nuclear Information System (INIS)

    Eilbeck, K.E.; Reeve, P.

    2009-01-01

    Sellafield Site is a compact and complex site which since the 1940's has been home to a range of facilities associated with the production and reprocessing of fissile material. The site contains the UK equivalent of the Chicago Pile-1 reactor, Hanford B Reactor, Rocky Flats Buildings 771 and 774, West Valley Main Process Plant Building, Savannah River Vitrification Plant, Savannah River MOX Plant, Savannah River F Canyon, Hanford 222 Analytical Laboratory, Savannah River K-, L-, and P-Basins, and the Fort St. Vrain Reactor all in an area of approximately 1000 acres. Spent fuel reprocessing is still undertaken on site; however waste management and decommissioning activities are of increasing importance. These include the emptying and removal of fragile ponds and silos containing significant radioactive inventories, the decommissioning of reactors (including the world's first commercial reactor for power generation and the Windscale Piles, the site of a reactor fire in the late 1950's) and the construction of a new generation of vitrification and encapsulation plants. Leaks, spills and on-site disposals during the site's industrial lifetime have resulted in a legacy of fission products and other radionuclides in the ground and groundwater. Volumes of contaminated ground have been estimated as being as much as 18 million m 3 and an estimated below ground inventory of approximately 1.8 E16 Bq. These have all occurred within close proximity to a range of receptors including farm land and the sea. The cramped nature of the facilities on site, overlapping source terms and ongoing decommissioning, waste management and operating activities all raise significant challenges in the management and remediation of contaminated land and groundwater. The strategy to address these challenges includes: 1. Data collection, management and interpretation. The congested nature of the site and the age of some of the monitoring facilities has resulted in particular difficulties. For

  13. Properties of bilateral spinocerebellar activation of cerebellar cortical neurons

    Directory of Open Access Journals (Sweden)

    Pontus eGeborek

    2014-10-01

    Full Text Available We aimed to explore the cerebellar cortical inputs from two spinocerebellar pathways, the spinal border cell-component of the ventral spinocerebellar tract (SBC-VSCT and the dorsal spinocerebellar tract (DSCT, respectively, in the sublobule C1 of the cerebellar posterior lobe. The two pathways were activated by electrical stimulation of the contralateral lateral funiculus (coLF and the ipsilateral LF (iLF at lower thoracic levels. Most granule cells in sublobule C1 did not respond at all but part of the granule cell population displayed high-intensity responses to either coLF or iLF stimulation. As a rule, Golgi cells and Purkinje cell simple spikes responded to input from both LFs, although Golgi cells could be more selective. In addition, a small population of granule cells responded to input from both the coLF and the iLF. However, in these cases, similarities in the temporal topography and magnitude of the responses suggested that the same axons were stimulated from the two LFs, i.e. that the axons of individual spinocerebellar neurons could be present in both funiculi. This was also confirmed for a population of spinal neurons located within known locations of SBC-VSCT neurons and dorsal horn DSCT neurons. We conclude that bilateral spinocerebellar responses can occur in cerebellar granule cells, but the VSCT and DSCT systems that provide the input can also be organized bilaterally. The implications for the traditional functional separation of VSCT and DSCT systems and the issue whether granule cells primarily integrate functionally similar information or not are discussed.

  14. 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

    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......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...

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

    Science.gov (United States)

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

    2015-08-01

    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.

  16. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  17. Biophysical Model of Cortical Network Activity and the Influence of Electrical Stimulation

    Science.gov (United States)

    2015-11-13

    model, multicompartment model, subdural cortical stimulation, anode, cathode, epilepsy REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S...and axon orientation in respect to the electrode position. 4) A single stimulation pulse causes a sequence of action potentials ectopically generated...Bergey, P.J. Franaszczuk. Phase-dependent stimulation effects on bursting activity in a neural network cortical simulation, Epilepsy Research (07 2008

  18. Imaging cortical activity following affective stimulation with a high temporal and spatial resolution

    Directory of Open Access Journals (Sweden)

    Catani Claudia

    2009-07-01

    Full Text Available Abstract Background The affective and motivational relevance of a stimulus has a distinct impact on cortical processing, particularly in sensory areas. However, the spatial and temporal dynamics of this affective modulation of brain activities remains unclear. The purpose of the present study was the development of a paradigm to investigate the affective modulation of cortical networks with a high temporal and spatial resolution. We assessed cortical activity with MEG using a visual steady-state paradigm with affective pictures. A combination of a complex demodulation procedure with a minimum norm estimation was applied to assess the temporal variation of the topography of cortical activity. Results Statistical permutation analyses of the results of the complex demodulation procedure revealed increased steady-state visual evoked field amplitudes over occipital areas following presentation of affective pictures compared to neutral pictures. This differentiation shifted in the time course from occipital regions to parietal and temporal regions. Conclusion It can be shown that stimulation with affective pictures leads to an enhanced activity in occipital region as compared to neutral pictures. However, the focus of differentiation is not stable over time but shifts into temporal and parietal regions within four seconds of stimulation. Thus, it can be crucial to carefully choose regions of interests and time intervals when analyzing the affective modulation of cortical activity.

  19. Auditory cortical activation and plasticity after cochlear implantation measured by PET using fluorodeoxyglucose.

    Science.gov (United States)

    Łukaszewicz-Moszyńska, Zuzanna; Lachowska, Magdalena; Niemczyk, Kazimierz

    2014-01-01

    The purpose of this study was to evaluate possible relationships between duration of cochlear implant use and results of positron emission tomography (PET) measurements in the temporal lobes performed while subjects listened to speech stimuli. Other aspects investigated were whether implantation side impacts significantly on cortical representations of functions related to understanding speech (ipsi- or contralateral to the implanted side) and whether any correlation exists between cortical activation and speech therapy results. Objective cortical responses to acoustic stimulation were measured, using PET, in nine cochlear implant patients (age range: 15 to 50 years). All the patients suffered from bilateral deafness, were right-handed, and had no additional neurological deficits. They underwent PET imaging three times: immediately after the first fitting of the speech processor (activation of the cochlear implant), and one and two years later. A tendency towards increasing levels of activation in areas of the primary and secondary auditory cortex on the left side of the brain was observed. There was no clear effect of the side of implantation (left or right) on the degree of cortical activation in the temporal lobe. However, the PET results showed a correlation between degree of cortical activation and speech therapy results.

  20. Weak correlations between hemodynamic signals and ongoing neural activity during the resting state

    Science.gov (United States)

    Winder, Aaron T.; Echagarruga, Christina; Zhang, Qingguang; Drew, Patrick J.

    2017-01-01

    Spontaneous fluctuations in hemodynamic signals in the absence of a task or overt stimulation are used to infer neural activity. We tested this coupling by simultaneously measuring neural activity and changes in cerebral blood volume (CBV) in the somatosensory cortex of awake, head-fixed mice during periods of true rest, and during whisker stimulation and volitional whisking. Here we show that neurovascular coupling was similar across states, and large spontaneous CBV changes in the absence of sensory input were driven by volitional whisker and body movements. Hemodynamic signals during periods of rest were weakly correlated with neural activity. Spontaneous fluctuations in CBV and vessel diameter persisted when local neural spiking and glutamatergic input was blocked, and during blockade of noradrenergic receptors, suggesting a non-neuronal origin for spontaneous CBV fluctuations. Spontaneous hemodynamic signals reflect a combination of behavior, local neural activity, and putatively non-neural processes. PMID:29184204

  1. On-going and some future safety related activities of the OECD/NEA

    International Nuclear Information System (INIS)

    Frescura, G.

    2001-01-01

    The CSNI and CNRA structures and current activities of direct relevance to WWERs are presented. The nuclear regulatory challenges arising from economic deregulation like: direct safety challenges, infrastructure issues, increased pressure on regulatory bodies etc. are given. The OECD/NEA initiatives on assuring nuclear safety competence are mentioned

  2. Cortical connective field estimates from resting state fMRI activity

    NARCIS (Netherlands)

    Gravel, Nicolas; Harvey, Ben; Nordhjem, Barbara; Haak, Koen V.; Dumoulin, Serge O.; Renken, Remco; Curcic-Blake, Branisalava; Cornelissen, Frans W.

    2014-01-01

    One way to study connectivity in visual cortical areas is by examining spontaneous neural activity. In the absence of visual input, such activity remains shaped by the underlying neural architecture and, presumably, may still reflect visuotopic organization. Here, we applied population connective

  3. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    International Nuclear Information System (INIS)

    Koonen, E.; Gubel, P.

    1994-01-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  4. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Koonen, E; Gubel, P [BR2 Department, Belgian Nuclear Research Center, CEN/SCK, Mol (Belgium)

    1993-07-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  5. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    International Nuclear Information System (INIS)

    Koonen, E.; Gubel, P.

    1993-01-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  6. Cortical activation pattern during shoulder simple versus vibration exercises: a functional near infrared spectroscopy study

    Directory of Open Access Journals (Sweden)

    Sung Ho Jang

    2017-01-01

    Full Text Available To date, the cortical effect of exercise has not been fully elucidated. Using the functional near infrared spectroscopy, we attempted to compare the cortical effect between shoulder vibration exercise and shoulder simple exercise. Eight healthy subjects were recruited for this study. Two different exercise tasks (shoulder vibration exercise using the flexible pole and shoulder simple exercise were performed using a block paradigm. We measured the values of oxygenated hemoglobin in the four regions of interest: the primary sensory-motor cortex (SM1 total, arm somatotopy, and leg and trunk somatotopy, the premotor cortex, the supplementary motor area, and the prefrontal cortex. During shoulder vibration exercise and shoulder simple exercise, cortical activation was observed in SM1 (total, arm somatotopy, and leg and trunk somatotopy, premotor cortex, supplementary motor area, and prefrontal cortex. Higher oxygenated hemoglobin values were also observed in the areas of arm somatotopy of SM1 compared with those of other regions of interest. However, no significant difference in the arm somatotopy of SM1 was observed between the two exercises. By contrast, in the leg and trunk somatotopy of SM1, shoulder vibration exercise led to a significantly higher oxy-hemoglobin value than shoulder simple exercise. These two exercises may result in cortical activation effects for the motor areas relevant to the shoulder exercise, especially in the arm somatotopy of SM1. However, shoulder vibration exercise has an additional cortical activation effect for the leg and trunk somatotopy of SM1.

  7. Cortical activation pattern during shoulder simple versus vibration exercises: a functional near infrared spectroscopy study.

    Science.gov (United States)

    Jang, Sung Ho; Yeo, Sang Seok; Lee, Seung Hyun; Jin, Sang Hyun; Lee, Mi Young

    2017-08-01

    To date, the cortical effect of exercise has not been fully elucidated. Using the functional near infrared spectroscopy, we attempted to compare the cortical effect between shoulder vibration exercise and shoulder simple exercise. Eight healthy subjects were recruited for this study. Two different exercise tasks (shoulder vibration exercise using the flexible pole and shoulder simple exercise) were performed using a block paradigm. We measured the values of oxygenated hemoglobin in the four regions of interest: the primary sensory-motor cortex (SM1 total, arm somatotopy, and leg and trunk somatotopy), the premotor cortex, the supplementary motor area, and the prefrontal cortex. During shoulder vibration exercise and shoulder simple exercise, cortical activation was observed in SM1 (total, arm somatotopy, and leg and trunk somatotopy), premotor cortex, supplementary motor area, and prefrontal cortex. Higher oxygenated hemoglobin values were also observed in the areas of arm somatotopy of SM1 compared with those of other regions of interest. However, no significant difference in the arm somatotopy of SM1 was observed between the two exercises. By contrast, in the leg and trunk somatotopy of SM1, shoulder vibration exercise led to a significantly higher oxy-hemoglobin value than shoulder simple exercise. These two exercises may result in cortical activation effects for the motor areas relevant to the shoulder exercise, especially in the arm somatotopy of SM1. However, shoulder vibration exercise has an additional cortical activation effect for the leg and trunk somatotopy of SM1.

  8. Complement is activated in progressive multiple sclerosis cortical grey matter lesions.

    Science.gov (United States)

    Watkins, Lewis M; Neal, James W; Loveless, Sam; Michailidou, Iliana; Ramaglia, Valeria; Rees, Mark I; Reynolds, Richard; Robertson, Neil P; Morgan, B Paul; Howell, Owain W

    2016-06-22

    The symptoms of multiple sclerosis (MS) are caused by damage to myelin and nerve cells in the brain and spinal cord. Inflammation is tightly linked with neurodegeneration, and it is the accumulation of neurodegeneration that underlies increasing neurological disability in progressive MS. Determining pathological mechanisms at play in MS grey matter is therefore a key to our understanding of disease progression. We analysed complement expression and activation by immunocytochemistry and in situ hybridisation in frozen or formalin-fixed paraffin-embedded post-mortem tissue blocks from 22 progressive MS cases and made comparisons to inflammatory central nervous system disease and non-neurological disease controls. Expression of the transcript for C1qA was noted in neurons and the activation fragment and opsonin C3b-labelled neurons and glia in the MS cortical and deep grey matter. The density of immunostained cells positive for the classical complement pathway protein C1q and the alternative complement pathway activation fragment Bb was significantly increased in cortical grey matter lesions in comparison to control grey matter. The number of cells immunostained for the membrane attack complex was elevated in cortical lesions, indicating complement activation to completion. The numbers of classical (C1-inhibitor) and alternative (factor H) pathway regulator-positive cells were unchanged between MS and controls, whilst complement anaphylatoxin receptor-bearing microglia in the MS cortex were found closely apposed to cortical neurons. Complement immunopositive neurons displayed an altered nuclear morphology, indicative of cell stress/damage, supporting our finding of significant neurodegeneration in cortical grey matter lesions. Complement is activated in the MS cortical grey matter lesions in areas of elevated numbers of complement receptor-positive microglia and suggests that complement over-activation may contribute to the worsening pathology that underlies the

  9. Ongoing disease activity and changing categories in a long-term nordic cohort study of juvenile idiopathic arthritis

    DEFF Research Database (Denmark)

    Nordal, Ellen; Zak, Marek; Aalto, Kristiina

    2011-01-01

    ), including biologic medications, were used in 58.0% of the children during the observation period. Ongoing disease activity was mostly mild, but 22.9% developed some JIA-related damage. At the last follow-up, remission off medication was found in 42.4% of the children, 8.9% were in remission on medication...... results underline the need to identify early predictors of outcome, to further improve therapy and to continue long-term follow-up of children with JIA....

  10. Cortical activation and attentional control in ADAH subtypes

    Directory of Open Access Journals (Sweden)

    Paloma González-Castro

    2010-01-01

    Full Text Available Uno de los trastornos que más condiciona el rendimiento escolar es eldéficit de atención aislado o asociado a hiperactividad o impulsividad. Este trastorno plantea dificultades a los propios estudiantes, tanto en el área verbal como en razonamiento y cálculo, así como también a sus profesores, como consecuencia de los comportamientos disruptivos. Los criterios establecidos por el Manual Diagnóstico y Estadístico de los Trastornos Mentales 4ª edición -revisada son uno de los procedimientos más aceptados para diagnosticar el déficit, distinguiéndose tres subtipos: inatento, hiperactivo-impulsivo y combinado. El objetivo central de la presente investigación ha sido contrastar si existen patrones de activación cortical y control ejecutivo diferenciales para estos tres tipos de sujetos con Trastorno por Déficit de Atención con Híperactividad (TDAH y para el grupo control sin TDAH. La muestra utilizada estaba formada por 220 estudiantes, de edades comprendidas entre 6 y 12 años: 56 grupo control, 54 con predominio de déficit de atención, 57 con déficit de atención e hiperactividad y 53 con predominio de hiperactividad-impulsividad. Los resultados obtenidos muestran que los cuatro grupos de sujetos se diferencian significativamente entre sí en las dos variables de activación cortical evaluadas (central y prefrontal, y en las cinco de control ejecutivo (inatención, impulsividad, tiempo de respuesta, variabilidad e índice general de control ejecutivo. Las comparaciones múltiples entre grupos confirman las hipótesis planteadas. Los resultados obtenidos abren una vía de gran interés cara a una evaluación diagnóstica objetiva y fiable, y a una intervención farmacológica y conductual ajustada a cada situación concreta.

  11. OECD/NEA Ongoing activities related to the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Cornet, S.M.; McCarthy, K.; Chauvin, N.

    2013-01-01

    As part of its role in encouraging international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to the Nuclear Fuel Cycle. The Nuclear Science Committee (NSC) Working Party on Scientific Issues of the Nuclear Fuel Cycle (WPFC) comprises five different expert groups covering all aspects of the fuel cycle from front to back-end. Activities related to fuels, materials, physics, separation chemistry, and fuel cycles scenarios are being undertaken. By publishing state-of-the-art reports and organizing workshops, the groups are able to disseminate recent research advancements to the international community. Current activities mainly focus on advanced nuclear systems, and experts are working on analyzing results and establishing challenges associated to the adoption of new materials and fuels. By comparing different codes, the Expert Group on Advanced Fuel Cycle Scenarios is aiming at gaining further understanding of the scientific issues and specific national needs associated with the implementation of advanced fuel cycles. At the back end of the fuel cycle, separation technologies (aqueous and pyrochemical processing) are being assessed. Current and future activities comprise studies on minor actinides separation and post Fukushima studies. Regular workshops are also organized to discuss recent developments on Partitioning and Transmutation. In addition, the Nuclear Development Committee (NDC) focuses on the analysis of the economics of nuclear power across the fuel cycle in the context of changes of electricity markets, social acceptance and technological advances and assesses the availability of the nuclear fuel and infrastructure required for the deployment of existing and future nuclear power. The Expert Group on the Economics of the Back End of the Nuclear Fuel Cycle (EBENFC), in particular, is looking at assessing economic and financial issues related to the long term management of spent nuclear fuel. (authors)

  12. On-going activities in Belgium in the field of FR & ADS: The progress since 2010

    International Nuclear Information System (INIS)

    De Bruyn, Didier

    2012-01-01

    Some R&D achievements: • LEXUR II: investigate combined irradiation & LBE environment; irradiation in BOR60; 1st PIE currently running; • FP7 MAX (Myrrha Accelerator eXperiments) started, dealing with reliability & availability; • RHAPTER (Remote HAndling Proof-of-principle TEst Rig) : commissioning running; • LiLIPuTTeR (Liquid Lead-bismuth Innovative Pump Technology Test Rig): now used to test pump components; • HELIOS (rig for experimental gas – liquid oxygen conditioning programme): under commissioning; support for other experimental activities

  13. Ongoing activity in temporally coherent networks predicts intra-subject fluctuation of response time to sporadic executive control demands.

    Science.gov (United States)

    Nozawa, Takayuki; Sugiura, Motoaki; Yokoyama, Ryoichi; Ihara, Mizuki; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Kanno, Akitake; Kawashima, Ryuta

    2014-01-01

    Can ongoing fMRI BOLD signals predict fluctuations in swiftness of a person's response to sporadic cognitive demands? This is an important issue because it clarifies whether intrinsic brain dynamics, for which spatio-temporal patterns are expressed as temporally coherent networks (TCNs), have effects not only on sensory or motor processes, but also on cognitive processes. Predictivity has been affirmed, although to a limited extent. Expecting a predictive effect on executive performance for a wider range of TCNs constituting the cingulo-opercular, fronto-parietal, and default mode networks, we conducted an fMRI study using a version of the color-word Stroop task that was specifically designed to put a higher load on executive control, with the aim of making its fluctuations more detectable. We explored the relationships between the fluctuations in ongoing pre-trial activity in TCNs and the task response time (RT). The results revealed the existence of TCNs in which fluctuations in activity several seconds before the onset of the trial predicted RT fluctuations for the subsequent trial. These TCNs were distributed in the cingulo-opercular and fronto-parietal networks, as well as in perceptual and motor networks. Our results suggest that intrinsic brain dynamics in these networks constitute "cognitive readiness," which plays an active role especially in situations where information for anticipatory attention control is unavailable. Fluctuations in these networks lead to fluctuations in executive control performance.

  14. Spatiotemporal dynamics of word retrieval in speech production revealed by cortical high-frequency band activity.

    Science.gov (United States)

    Riès, Stephanie K; Dhillon, Rummit K; Clarke, Alex; King-Stephens, David; Laxer, Kenneth D; Weber, Peter B; Kuperman, Rachel A; Auguste, Kurtis I; Brunner, Peter; Schalk, Gerwin; Lin, Jack J; Parvizi, Josef; Crone, Nathan E; Dronkers, Nina F; Knight, Robert T

    2017-06-06

    Word retrieval is core to language production and relies on complementary processes: the rapid activation of lexical and conceptual representations and word selection, which chooses the correct word among semantically related competitors. Lexical and conceptual activation is measured by semantic priming. In contrast, word selection is indexed by semantic interference and is hampered in semantically homogeneous (HOM) contexts. We examined the spatiotemporal dynamics of these complementary processes in a picture naming task with blocks of semantically heterogeneous (HET) or HOM stimuli. We used electrocorticography data obtained from frontal and temporal cortices, permitting detailed spatiotemporal analysis of word retrieval processes. A semantic interference effect was observed with naming latencies longer in HOM versus HET blocks. Cortical response strength as indexed by high-frequency band (HFB) activity (70-150 Hz) amplitude revealed effects linked to lexical-semantic activation and word selection observed in widespread regions of the cortical mantle. Depending on the subsecond timing and cortical region, HFB indexed semantic interference (i.e., more activity in HOM than HET blocks) or semantic priming effects (i.e., more activity in HET than HOM blocks). These effects overlapped in time and space in the left posterior inferior temporal gyrus and the left prefrontal cortex. The data do not support a modular view of word retrieval in speech production but rather support substantial overlap of lexical-semantic activation and word selection mechanisms in the brain.

  15. On-going P and T activities at the OECD Nuclear Energy Agency

    International Nuclear Information System (INIS)

    Cornet, S.; Gulliford, J.

    2015-01-01

    Partitioning and transmutation is considered as a potential route for improved management of spent nuclear fuel through the reduction of long lived radionuclides. Many countries are conducting R and D programmes dedicated to developing the necessary technologies. Through international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to transmutation and partitioning covering both strategic and scientific issues. The activity is carried out by expert groups of the NSC Working Party on Scientific Issues of the Fuel Cycle (WPFC) whose programme of work covers existing and advanced nuclear fuel cycles, including fuel cycle scenarios, separation chemistry, innovative fuels and materials, and waste management. Outputs include reports on the advances and progresses of R and D in P and T which help identify gaps and needs in this field. (authors)

  16. Nuclear energy for space: Past CEA activities and ongoing OPUS studies

    International Nuclear Information System (INIS)

    Raepsaet, Xavier; Marion, Denis; Valentian, Dominique

    2006-01-01

    Since the beginning of space activities, solar and nuclear energy have been identified as the only available options for extended missions according to present knowledge. Both types have been used extensively for missions on Earth orbit, interplanetary space and planetary/lunar surface. However, the intensity of solar irradiation decreases with the square of the distance from the Sun. Future scientific and human explorations will take benefits of using a safe in-space nuclear reactor for providing both sufficient electric energy and efficient performance for a space propulsion. The first part of the paper presents a brief status of the different types of nuclear power sources, their characteristics and their field of applications. Previous CEA's projects of space nuclear fission reactors that have been studied in the past will also be discussed; the ERATO project in the 80's (design of a Nuclear Electric Propulsion system of 20 to 200 kWe) and the MAPS project in the 90's (definition of a Nuclear Thermal Propulsion system of 300 MWth for 72 kN of thrust). According to the recent road-maps, CEA decided to maintain a waking state in its spatial nuclear activities by carrying out some conceptual design studies of Nuclear Electric Power systems in the range of 100-500 kWe. The second part of the paper describes the main characteristics of this Optimized Propulsion Unit System (OPUS studies) and its different components. These characteristics, the basic options of the OPUS system that have been selected and the reasons associated to those choices are examined. Especially, the nuclear reactor has been defined considering the possible synergies with the next generation of terrestrial nuclear reactor (International Generation IV Forum). After two successive sets of studies, two different versions of this nuclear system have emerged. The first one is a fast, high-temperature helium cooled reactor, coupled to a direct reheated Brayton cycle. This version is technically the

  17. Applications of brain blood flow imaging in behavioral neurophysiology: cortical field activation hypothesis

    International Nuclear Information System (INIS)

    Roland, P.E.

    1985-01-01

    The 133 xenon intracarotid method for rCBF measurements has been a very useful method for functional mapping and functional dissection of the cerebral cortex in humans. With this method it has been shown that different types of cortical information treatment activate different cortical areas and furthermore that sensory and motor functions of the cerebral cortex could be dissected into anatomical and informational subcomponents by behavioral manipulations. The brain organizes its own activity. One of the principles of organization was that the brain could recruit in advance cortical fields that were expected to participate in a certain type of information operation. During brain work in awake human beings the cerebral cortex was activated in fields that, projected on the cerebral surface, most often had a size greater than 3 CM 2 . Such activated fields appeared no matter which type of information processing was going on in the brain: during planning and execution of voluntary movements, during preparation for sensory information processing, and during sensory information processing, as well as during cognitive brain work and retrieval of specific memories. Therefore, it was hypothesized that cortical field activation was the physiological manifestation of normal brain work in awake humans

  18. Applications of brain blood flow imaging in behavioral neurophysiology: cortical field activation hypothesis

    Energy Technology Data Exchange (ETDEWEB)

    Roland, P.E.

    1985-01-01

    The /sup 133/xenon intracarotid method for rCBF measurements has been a very useful method for functional mapping and functional dissection of the cerebral cortex in humans. With this method it has been shown that different types of cortical information treatment activate different cortical areas and furthermore that sensory and motor functions of the cerebral cortex could be dissected into anatomical and informational subcomponents by behavioral manipulations. The brain organizes its own activity. One of the principles of organization was that the brain could recruit in advance cortical fields that were expected to participate in a certain type of information operation. During brain work in awake human beings the cerebral cortex was activated in fields that, projected on the cerebral surface, most often had a size greater than 3 CM/sup 2/. Such activated fields appeared no matter which type of information processing was going on in the brain: during planning and execution of voluntary movements, during preparation for sensory information processing, and during sensory information processing, as well as during cognitive brain work and retrieval of specific memories. Therefore, it was hypothesized that cortical field activation was the physiological manifestation of normal brain work in awake humans.

  19. The Estimation of Cortical Activity for Brain-Computer Interface: Applications in a Domotic Context

    Directory of Open Access Journals (Sweden)

    F. Babiloni

    2007-08-01

    Full Text Available In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm technique. Results showed that the use of the cortical-estimated activity instead of the unprocessed EEG improves the recognition of the mental states associated to the limb movement imagination in the group of normal subjects. The BCI methodology presented here has been used in a group of disabled patients in order to give them a suitable control of several electronic devices disposed in a three-room environment devoted to the neurorehabilitation. Four of six patients were able to control several electronic devices in this domotic context with the BCI system.

  20. Detection of cortical activities on eye movement using functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masaki; Kawai, Kazushige; Kitahara, Kenji [Jikei Univ., Tokyo (Japan). School of Medicine; Soulie, D.; Cordoliani, Y.S.; Iba-Zizen, M.T.; Cabanis, E.A.

    1997-11-01

    Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann`s areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann`s areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement. (author)

  1. Detection of cortical activities on eye movement using functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Yoshida, Masaki; Kawai, Kazushige; Kitahara, Kenji; Soulie, D.; Cordoliani, Y.S.; Iba-Zizen, M.T.; Cabanis, E.A.

    1997-01-01

    Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann's areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann's areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement. (author)

  2. Subthalamic stimulation modulates cortical motor network activity and synchronization in Parkinson’s disease

    Science.gov (United States)

    Klotz, Rosa; Govindan, Rathinaswamy B.; Scholten, Marlieke; Naros, Georgios; Ramos-Murguialday, Ander; Bunjes, Friedemann; Meisner, Christoph; Plewnia, Christian; Krüger, Rejko

    2015-01-01

    Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson’s disease. Here, we set out to address the motor network activity and synchronization in Parkinson’s disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson’s disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-frequency event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-frequency domain were analysed to explore the cortico-cortical synchronization. The time-frequency modulations enabled us to select a time-frequency range relevant for motor processing. On these time-frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with ‘stimulation on’ compared to ‘stimulation off’ on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With ‘stimulation on’, interhemispheric cortico-cortical

  3. GDNF/GFRα1 Complex Abrogates Self-Renewing Activity of Cortical Neural Precursors Inducing Their Differentiation

    Directory of Open Access Journals (Sweden)

    Antonela Bonafina

    2018-03-01

    Full Text Available Summary: The balance between factors leading to proliferation and differentiation of cortical neural precursors (CNPs determines the correct cortical development. In this work, we show that GDNF and its receptor GFRα1 are expressed in the neocortex during the period of cortical neurogenesis. We show that the GDNF/GFRα1 complex inhibits the self-renewal capacity of mouse CNP cells induced by fibroblast growth factor 2 (FGF2, promoting neuronal differentiation. While GDNF leads to decreased proliferation of cultured cortical precursor cells, ablation of GFRα1 in glutamatergic cortical precursors enhances its proliferation. We show that GDNF treatment of CNPs promoted morphological differentiation even in the presence of the self-renewal-promoting factor, FGF2. Analysis of GFRα1-deficient mice shows an increase in the number of cycling cells during cortical development and a reduction in dendrite development of cortical GFRα1-expressing neurons. Together, these results indicate that GDNF/GFRα1 signaling plays an essential role in regulating the proliferative condition and the differentiation of cortical progenitors. : In this article, Ledda and colleagues show that GDNF acting through its receptor GFRα1 plays a critical role in the maturation of cortical progenitors by counteracting FGF2 self-renewal activity on neural stem cells and promoting neuronal differentiation. Keywords: GDNF, GFRα1, cortical precursors, proliferation, postmitotic neurons, neuronal differentiation

  4. Activation of mesocorticolimbic reward circuits for assessment of relief of ongoing pain: a potential biomarker of efficacy.

    Science.gov (United States)

    Xie, Jennifer Y; Qu, Chaoling; Patwardhan, Amol; Ossipov, Michael H; Navratilova, Edita; Becerra, Lino; Borsook, David; Porreca, Frank

    2014-08-01

    Preclinical assessment of pain has increasingly explored operant methods that may allow behavioral assessment of ongoing pain. In animals with incisional injury, peripheral nerve block produces conditioned place preference (CPP) and activates the mesolimbic dopaminergic reward pathway. We hypothesized that activation of this circuit could serve as a neurochemical output measure of relief of ongoing pain. Medications commonly used clinically, including gabapentin and nonsteroidal anti-inflammatory drugs (NSAIDs), were evaluated in models of post-surgical (1 day after incision) or neuropathic (14 days after spinal nerve ligation [SNL]) pain to determine whether the clinical efficacy profile of these drugs in these pain conditions was reflected by extracellular dopamine (DA) release in the nucleus accumbens (NAc) shell. Microdialysis was performed in awake rats. Basal DA levels were not significantly different between experimental groups, and no significant treatment effects were seen in sham-operated animals. Consistent with clinical observation, spinal clonidine produced CPP and produced a dose-related increase in net NAc DA release in SNL rats. Gabapentin, commonly used to treat neuropathic pain, produced increased NAc DA in rats with SNL but not in animals with incisional, injury. In contrast, ketorolac or naproxen produced increased NAc DA in animals with incisional but not neuropathic pain. Increased extracellular NAc DA release was consistent with CPP and was observed selectively with treatments commonly used clinically for post-surgical or neuropathic pain. Evaluation of NAc DA efflux in animal pain models may represent an objective neurochemical assay that may serve as a biomarker of efficacy for novel pain-relieving mechanisms. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  5. 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.

  6. Dampened hippocampal oscillations and enhanced spindle activity in an asymptomatic model of developmental cortical malformations

    Directory of Open Access Journals (Sweden)

    Elena eCid

    2014-04-01

    Full Text Available Developmental cortical malformations comprise a large spectrum of histopathological brain abnormalities and syndromes. Their genetic, developmental and clinical complexity suggests they should be better understood in terms of the complementary action of independently timed perturbations (i.e. the multiple-hit hypothesis. However, understanding the underlying biological processes remains puzzling. Here we induced developmental cortical malformations in offspring, after intraventricular injection of methylazoxymethanol (MAM in utero in mice. We combined extensive histological and electrophysiological studies to characterize the model. We found that MAM injections at E14 and E15 induced a range of cortical and hippocampal malformations resembling histological alterations of specific genetic mutations and transplacental mitotoxic agent injections. However, in contrast to most of these models, intraventricularly MAM-injected mice remained asymptomatic and showed no clear epilepsy-related phenotype as tested in long-term chronic recordings and with pharmacological manipulations. Instead, they exhibited a non-specific reduction of hippocampal-related brain oscillations (mostly in CA1; including theta, gamma and HFOs; and enhanced thalamocortical spindle activity during non-REM sleep. These data suggest that developmental cortical malformations do not necessarily correlate with epileptiform activity. We propose that the intraventricular in utero MAM approach exhibiting a range of rhythmopathies is a suitable model for multiple-hit studies of associated neurological disorders.

  7. Cortical GABAergic excitation contributes to epileptic activities around human glioma

    Science.gov (United States)

    Pallud, Johan; Varlet, Pascale; Cresto, Noemie; Baulac, Michel; Duyckaerts, Charles; Kourdougli, Nazim; Chazal, Geneviève; Devaux, Bertrand; Rivera, Claudio; Miles, Richard; Capelle, Laurent; Huberfeld, Gilles

    2015-01-01

    Rationale Diffuse brain gliomas induce seizures in a majority of patients. As in most epileptic disorders, excitatory glutamatergic mechanisms are involved in the generation of epileptic activities in the neocortex surrounding gliomas. However, chloride homeostasis is known to be perturbed in glial tumor cells. Thus the contribution of GABAergic mechanisms which depend on intracellular chloride and which are defective or pro-epileptic in other structural epilepsies merits closer study. Objective We studied in neocortical slices from the peritumoral security margin resected around human brain gliomas, the occurrence, networks, cells and signaling basis of epileptic activities. Results Postoperative glioma tissue from 69% of patients spontaneously generated interictal-like discharges. These events were synchronized, with a high frequency oscillation signature, in superficial layers of neocortex around glioma areas with tumor infiltration. Interictal-like events depended on both glutamatergic transmission and on depolarizing GABAergic signaling. About 65% of pyramidal cells were depolarized by GABA released by interneurons. This effect was related to perturbations in Chloride homeostasis, due to changes in expression of chloride co-transporters: KCC2 was reduced and expression of NKCC1 increased. Ictal-like activities were initiated by convulsant stimuli exclusively in these epileptogenic areas. Conclusions Epileptic activities are sustained by excitatory effects of GABA in the peritumoral human neocortex, as in temporal lobe epilepsies. Glutamate and GABA signaling are involved in oncogenesis and chloride homeostasis is perturbed. These same factors, induce an imbalance between synaptic excitatory and inhibition underly epileptic discharges in tumor patients. PMID:25009229

  8. Nanomolar Bifenthrin Alters Synchronous Ca2+ Oscillations and Cortical Neuron Development Independent of Sodium Channel Activity

    OpenAIRE

    Cao, Zhengyu; Cui, Yanjun; Nguyen, Hai M.; Jenkins, David Paul; Wulff, Heike; Pessah, Isaac N.

    2014-01-01

    Bifenthrin, a relatively stable type I pyrethroid that causes tremors and impairs motor activity in rodents, is broadly used. We investigated whether nanomolar bifenthrin alters synchronous Ca 2+ oscillations (SCOs) necessary for activity-dependent dendritic development. Primary mouse cortical neurons were cultured 8 or 9 days in vitro (DIV), loaded with the Ca2+ indicator Fluo-4, and imaged using a Fluorescence Imaging Plate Reader Tetra. Acute exposure to bifenthrin rapidly increased the fr...

  9. Sensorimotor cortical activity in patients with complete spinal cord injury: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Sabbah, P; de, Schonen S; Leveque, C; Gay, S; Pfefer, F; Nioche, C; Sarrazin, J L; Barouti, H; Tadie, M; Cordoliani, Y S

    2002-01-01

    Residual activation of the cortex was investigated in nine patients with complete spinal cord injury between T6 and L1 by functional magnetic resonance imaging (fMRI). Brain activations were recorded under four conditions: (1) a patient attempting to move his toes with flexion-extension, (2) a patient imagining the same movement, (3) passive proprio-somesthesic stimulation of the big toes without visual control, and (4) passive proprio-somesthesic stimulation of the big toes with visual control by the patient. Passive proprio-somesthesic stimulation of the toes generated activation posterior to the central sulcus in the three patients who also showed a somesthesic evoked potential response to somesthesic stimulation. When performed under visual control, activations were observed in two more patients. In all patients, activations were found in the cortical areas involved in motor control (i.e., primary sensorimotor cortex, premotor regions and supplementary motor area [SMA]) during attempts to move or mental imagery of these tasks. It is concluded that even several years after injury with some local cortical reorganization, activation of lower limb cortical networks can be generated either by the attempt to move, the mental evocation of the action, or the visual feedback of a passive proprio-somesthesic stimulation.

  10. Selection of independent components based on cortical mapping of electromagnetic activity

    Science.gov (United States)

    Chan, Hui-Ling; Chen, Yong-Sheng; Chen, Li-Fen

    2012-10-01

    Independent component analysis (ICA) has been widely used to attenuate interference caused by noise components from the electromagnetic recordings of brain activity. However, the scalp topographies and associated temporal waveforms provided by ICA may be insufficient to distinguish functional components from artifactual ones. In this work, we proposed two component selection methods, both of which first estimate the cortical distribution of the brain activity for each component, and then determine the functional components based on the parcellation of brain activity mapped onto the cortical surface. Among all independent components, the first method can identify the dominant components, which have strong activity in the selected dominant brain regions, whereas the second method can identify those inter-regional associating components, which have similar component spectra between a pair of regions. For a targeted region, its component spectrum enumerates the amplitudes of its parceled brain activity across all components. The selected functional components can be remixed to reconstruct the focused electromagnetic signals for further analysis, such as source estimation. Moreover, the inter-regional associating components can be used to estimate the functional brain network. The accuracy of the cortical activation estimation was evaluated on the data from simulation studies, whereas the usefulness and feasibility of the component selection methods were demonstrated on the magnetoencephalography data recorded from a gender discrimination study.

  11. Spontaneous cortical activity reveals hallmarks of an optimal internal model of the environment.

    Science.gov (United States)

    Berkes, Pietro; Orbán, Gergo; Lengyel, Máté; Fiser, József

    2011-01-07

    The brain maintains internal models of its environment to interpret sensory inputs and to prepare actions. Although behavioral studies have demonstrated that these internal models are optimally adapted to the statistics of the environment, the neural underpinning of this adaptation is unknown. Using a Bayesian model of sensory cortical processing, we related stimulus-evoked and spontaneous neural activities to inferences and prior expectations in an internal model and predicted that they should match if the model is statistically optimal. To test this prediction, we analyzed visual cortical activity of awake ferrets during development. Similarity between spontaneous and evoked activities increased with age and was specific to responses evoked by natural scenes. This demonstrates the progressive adaptation of internal models to the statistics of natural stimuli at the neural level.

  12. Cortical activity patterns predict robust speech discrimination ability in noise

    Science.gov (United States)

    Shetake, Jai A.; Wolf, Jordan T.; Cheung, Ryan J.; Engineer, Crystal T.; Ram, Satyananda K.; Kilgard, Michael P.

    2012-01-01

    The neural mechanisms that support speech discrimination in noisy conditions are poorly understood. In quiet conditions, spike timing information appears to be used in the discrimination of speech sounds. In this study, we evaluated the hypothesis that spike timing is also used to distinguish between speech sounds in noisy conditions that significantly degrade neural responses to speech sounds. We tested speech sound discrimination in rats and recorded primary auditory cortex (A1) responses to speech sounds in background noise of different intensities and spectral compositions. Our behavioral results indicate that rats, like humans, are able to accurately discriminate consonant sounds even in the presence of background noise that is as loud as the speech signal. Our neural recordings confirm that speech sounds evoke degraded but detectable responses in noise. Finally, we developed a novel neural classifier that mimics behavioral discrimination. The classifier discriminates between speech sounds by comparing the A1 spatiotemporal activity patterns evoked on single trials with the average spatiotemporal patterns evoked by known sounds. Unlike classifiers in most previous studies, this classifier is not provided with the stimulus onset time. Neural activity analyzed with the use of relative spike timing was well correlated with behavioral speech discrimination in quiet and in noise. Spike timing information integrated over longer intervals was required to accurately predict rat behavioral speech discrimination in noisy conditions. The similarity of neural and behavioral discrimination of speech in noise suggests that humans and rats may employ similar brain mechanisms to solve this problem. PMID:22098331

  13. Human cortical activity evoked by contextual processing in attentional orienting.

    Science.gov (United States)

    Zhao, Shuo; Li, Chunlin; Uono, Shota; Yoshimura, Sayaka; Toichi, Motomi

    2017-06-07

    The ability to assess another person's direction of attention is paramount in social communication, many studies have reported a similar pattern between gaze and arrow cues in attention orienting. Neuroimaging research has also demonstrated no qualitative differences in attention to gaze and arrow cues. However, these studies were implemented under simple experiment conditions. Researchers have highlighted the importance of contextual processing (i.e., the semantic congruence between cue and target) in attentional orienting, showing that attentional orienting by social gaze or arrow cues could be modulated through contextual processing. Here, we examine the neural activity of attentional orienting by gaze and arrow cues in response to contextual processing using functional magnetic resonance imaging. The results demonstrated that the influence of neural activity through contextual processing to attentional orienting occurred under invalid conditions (when the cue and target were incongruent versus congruent) in the ventral frontoparietal network, although we did not identify any differences in the neural substrates of attentional orienting in contextual processing between gaze and arrow cues. These results support behavioural data of attentional orienting modulated by contextual processing based on the neurocognitive architecture.

  14. Temporal changes in cortical activation during conditioned pain modulation (CPM), a LORETA study.

    Science.gov (United States)

    Moont, Ruth; Crispel, Yonatan; Lev, Rina; Pud, Dorit; Yarnitsky, David

    2011-07-01

    For most healthy subjects, both subjective pain ratings and pain-evoked potentials are attenuated under conditioned pain modulation (CPM; formerly termed diffuse noxious inhibitory controls, or DNIC). Although essentially spinal-bulbar, this inhibition is under cortical control. This is the first study to observe temporal as well as spatial changes in cortical activations under CPM. Specifically, we aimed to investigate the interplay of areas involved in the perception and processing of pain and those involved in controlling descending inhibition. We examined brief consecutive poststimulus time windows of 50 ms using a method of source-localization from pain evoked potentials, sLORETA. This enabled determination of dynamic changes in localized cortical generators evoked by phasic noxious heat stimuli to the left volar forearm in healthy young males, with and without conditioning hot-water pain to the right hand. We found a CPM effect characterized by an initial increased activation in the orbitofrontal cortex (OFC) and amygdala at 250-300 ms poststimulus, which was correlated with the extent of psychophysical pain reduction. This was followed by reduced activations in the primary and secondary somatosensory cortices, supplementary motor area, posterior insula, and anterior cingulate cortex from 400 ms poststimulus. Our findings show that the prefrontal pain-controlling areas of OFC and amygdala increase their activity in parallel with subjective pain reduction under CPM, and that this increased activity occurs prior to reductions in activations of the pain sensory areas. In conclusion, achieving pain inhibition by the CPM process seems to be under control of the OFC and the amygdala. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  15. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  16. Nanofibrillar scaffolds induce preferential activation of Rho GTPases in cerebral cortical astrocytes

    Science.gov (United States)

    Tiryaki, Volkan Mujdat; Ayres, Virginia M; Khan, Adeel A; Ahmed, Ijaz; Shreiber, David I; Meiners, Sally

    2012-01-01

    Cerebral cortical astrocyte responses to polyamide nanofibrillar scaffolds versus poly-L-lysine (PLL)-functionalized planar glass, unfunctionalized planar Aclar coverslips, and PLL-functionalized planar Aclar surfaces were investigated by atomic force microscopy and immunocytochemistry. The physical properties of the cell culture environments were evaluated using contact angle and surface roughness measurements and compared. Astrocyte morphological responses, including filopodia, lamellipodia, and stress fiber formation, and stellation were imaged using atomic force microscopy and phalloidin staining for F-actin. Activation of the corresponding Rho GTPase regulators was investigated using immunolabeling with Cdc42, Rac1, and RhoA. Astrocytes cultured on the nanofibrillar scaffolds showed a unique response that included stellation, cell–cell interactions by stellate processes, and evidence of depression of RhoA. The results support the hypothesis that the extracellular environment can trigger preferential activation of members of the Rho GTPase family, with demonstrable morphological consequences for cerebral cortical astrocytes. PMID:22915841

  17. Tactile spatial working memory activates the dorsal extrastriate cortical pathway in congenitally blind individuals.

    Science.gov (United States)

    Bonino, D; Ricciardi, E; Sani, L; Gentili, C; Vanello, N; Guazzelli, M; Vecchi, T; Pietrini, P

    2008-09-01

    In sighted individuals, both the visual and tactile version of the same spatial working memory task elicited neural responses in the dorsal "where" cortical pathway (Ricciardi et al., 2006). Whether the neural response during the tactile working memory task is due to visually-based spatial imagery or rather reflects a more abstract, supramodal organization of the dorsal cortical pathway remains to be determined. To understand the role of visual experience on the functional organization of the dorsal cortical stream, using functional magnetic resonance imaging (fMRI) here we examined brain response in four individuals with congenital or early blindness and no visual recollection, while they performed the same tactile spatial working memory task, a one-back recognition of 2D and 3D matrices. The blind subjects showed a significant activation in bilateral posterior parietal cortex, dorsolateral and inferior prefrontal areas, precuneus, lateral occipital cortex, and cerebellum. Thus, dorsal occipito-parietal areas are involved in mental imagery dealing with spatial components in subjects without prior visual experience and in response to a non-visual task. These data indicate that recruitment of the dorsal cortical pathway in response to the tactile spatial working memory task is not mediated by visually-based imagery and that visual experience is not a prerequisite for the development of a more abstract functional organization of the dorsal stream. These findings, along with previous data indicating a similar supramodal functional organization within the ventral cortical pathway and the motion processing brain regions, may contribute to explain how individuals who are born deprived of sight are able to interact effectively with the surrounding world.

  18. Patterns of cortical activity during the observation of Public Service Announcements and commercial advertisings.

    Science.gov (United States)

    Vecchiato, Giovanni; Astolfi, Laura; Cincotti, Febo; De Vico Fallani, Fabrizio; Sorrentino, Domenica M; Mattia, Donatella; Salinari, Serenella; Bianchi, Luigi; Toppi, Jlena; Aloise, Fabio; Babiloni, Fabio

    2010-06-03

    In the present research we were interested to study the cerebral activity of a group of healthy subjects during the observation a documentary intermingled by a series of TV advertisements. In particular, we desired to examine whether Public Service Announcements (PSAs) are able to elicit a different pattern of activity, when compared with a different class of commercials, and correlate it with the memorization of the showed stimuli, as resulted from a following subject's verbal interview. We recorded the EEG signals from a group of 15 healthy subjects and applied the High Resolution EEG techniques in order to estimate and map their Power Spectral Density (PSD) on a realistic cortical model. The single subjects' activities have been z-score transformed and then grouped to define four different datasets, related to subjects who remembered and forgotten the PSAs and to subjects who remembered and forgotten cars commercials (CAR) respectively, which we contrasted to investigate cortical areas involved in this encoding process. The results we here present show that the cortical activity elicited during the observation of the TV commercials that were remembered (RMB) is higher and localized in the left frontal brain areas when compared to the activity elicited during the vision of the TV commercials that were forgotten (FRG) in theta and gamma bands for both categories of advertisements (PSAs and CAR). Moreover, the cortical maps associated with the PSAs also show an increase of activity in the alpha and beta band. In conclusion, the TV advertisements that will be remembered by the experimental population have increased their cerebral activity, mainly in the left hemisphere. These results seem to be congruent with and well inserted in the already existing literature, on this topic, related to the HERA model. The different pattern of activity in different frequency bands elicited by the observation of PSAs may be justified by the existence of additional cortical networks

  19. Effect of caffeine on preterm infants' cerebral cortical activity: an observational study.

    Science.gov (United States)

    Hassanein, Sahar M A; Gad, Ghada I; Ismail, Rania I H; Diab, Mohamed

    2015-01-01

    Our first aim was to investigate the effects of caffeine on preterm infants' respiratory functions and brain cortical activity (conventional and amplitude-integrated electroencephalography (cEEG and aEEG)). Secondary aim was to study its long-term effects on respiratory system and electroencephalographic maturation by 36 weeks post-menstrual age. Prospective observational study on 33 consecutively admitted preterm infants less than 34-weeks-gestation. cEEG and aEEG, cardiopulmonary and sleep state were recorded in 20 preterm infants, before, during and 2-hours after intravenous (IV) caffeine (caffeine Group), and for 13 preterms (control group). Both groups were subjected to assessment of cerebral cortical maturation by cEEG and aEEG at 36-weeks post-menstrual age as an outcome measure. IV caffeine administration significantly increased heart rate (p = 0.000), mean arterial blood pressure (p = 0.000), capillary oxygen saturation (p = 0.003), arousability (p = 0.000) and aEEG continuity (p = 0.002) after half an hour. No clinical seizures were recorded and non-significant difference was found in electrographic seizures activity in cEEG. At 36-weeks post-conceptional age, NICU stay was significantly longer in controls (p = 0.022). aEEG score was significantly higher in caffeine group than the control group, (p = 0.000). Caffeine increases preterm infants' cerebral cortical activity during infusion and results in cerebral cortical maturation at 36weeks, without increase in seizure activity.

  20. Reduction in Cortical Gamma Synchrony during Depolarized State of Slow Wave Activity in Mice

    Directory of Open Access Journals (Sweden)

    EUNJIN eHWANG

    2013-12-01

    Full Text Available EEG gamma band oscillations have been proposed to account for the neural synchronization crucial for perceptual integration. While increased gamma power and synchronization is generally observed during cognitive tasks performed during wake, several studies have additionally reported increased gamma power during sleep or anesthesia, raising questions about the characteristics of gamma oscillation during impaired consciousness and its role in conscious processing. Phase-amplitude modulation has been observed between slow wave activity (SWA, 0.5–4 Hz and gamma oscillations during ketamine/xylazine anesthesia or sleep, showing increased gamma activity corresponding to the depolarized (ON state of SWA. Here we divided gamma activity into its ON and OFF (hyperpolarized state components based on the phase of SWA induced by ketamine/xylazine anesthesia and compared their power and synchrony with wake state levels in mice. We further investigated the state-dependent changes in both gamma power and synchrony across primary motor and primary somatosensory cortical regions and their interconnected thalamic regions throughout anesthesia and recovery. As observed previously, gamma power was as high as during wake specifically during the ON state of SWA. However, the synchrony of this gamma activity between somatosensory-motor cortical regions was significantly reduced compared to the baseline wake state. In addition, the somatosensory-motor cortical synchrony of gamma oscillations was reduced and restored in an anesthetic state-dependent manner, reflecting the changing depth of anesthesia. Our results provide evidence that during anesthesia changes in long-range information integration between cortical regions might be more critical for changes in consciousness than changes in local gamma oscillatory power.

  1. Neutron activation analysis of medullar and cortical bone tissues from animals

    International Nuclear Information System (INIS)

    Takata, Marcelo Kazuo; Saiki, Mitiko

    2000-01-01

    In this work, neutron activation analysis was applied in the determination of the elements Ba, Br, Ca, Cl, Cr, Fe, K, Mg, Mn, Na, P, Rb, Sb, Sc, Sr and Zn present in animal bone tissues. The obtained results indicated a significant difference between the elemental concentrations present in medullar and cortical tissues. The results obtained for bone tissues from distinct animal species were also different. (author)

  2. Emergency preparedness activities during an ongoing seismic swarm: the experience of the 2011-2012 Pollino (Southern Italy) sequence

    Science.gov (United States)

    Masi, A.; Mucciarelli, M.; Chiauzzi, L.; De Costanzo, G.; Loperte, G.

    2012-04-01

    Facing natural disasters effects can be a very difficult task lacking suitable activities and tools to preventively prepare the involved community (people, authorities, professionals, …) to the expected events. Therefore, a suite of preventive actions should be carried out to mitigate natural risks, in particular working to reduce the territorial vulnerability with respect to the specific natural hazard at hand, and to increase people response capacity. In fact, building social capacity helps to increase the risk perception and the people capacity to adapt to and cope with natural hazards. Since October 2011 a seismic swarm is affecting the Pollino mountain range, Southern Italy. At present the sequence is still ongoing, with more than 500 events with M>1, at least 40 well perceived by the population and a maximum magnitude at 3.6. The area mainly affected by the seismic sequence includes 12 villages, with a total population of about 50.000 inhabitants and, according to the current seismic hazard map it has high seismicity level. Such area was hit by a magnitude Ml=5.7 event in 1998 that produced macroseismic intensity not higher that VII-VIII degree of MCS scale and caused one dead, some injured and widespread damage in at least six municipalities. During the sequence, the National Department of Civil Protection (DPC) and the Civil Protection of Basilicata Region decided to put in action some measures aimed at verifying and enhancing emergency preparedness. These actions have been carried out with a constant and fruitful collaboration among the main stakeholders involved (scientific community, local and national governmental agencies, civil protection volunteers, etc) trough the following main activities: 1. collaboration between scientific community and the local and national offices of Civil Protection especially in the relationship with local authorities (e.g. mayors, which are civil protection authorities in their municipality); 2. interaction between DPC

  3. SEP-induced activity and its thermographic cortical representation in a murine model.

    Science.gov (United States)

    Hoffmann, Klaus-Peter; Ruff, Roman; Kirsch, Matthias

    2013-06-01

    This article is a methodical report on the generation of reproducible changes in brain activity in a murine model. Somatosensory evoked potentials (SEP) are used to generate synchronized cortical activity. After electrical stimulation of mice forelimbs, the potentials were recorded with a flexible thin-film polyimide electrode structure directly from the cortex. Every registration included a simultaneous recording from both hemispheres that repeated four times to reproduce and compare the results. The SEPs in the murine model were shown to generate a very stable signal. The latency of the second positive wave (P2 wave) ranged between 16 and 19 ms, and the N1-P2 amplitude ranged between 39 and 48 µV. In addition, the temperature distribution of the cortex was acquired using infrared thermography. Surface cortical temperature changed during electrical stimulation without a clear hemispheric correlation. These initial results could be a step toward a better understanding of the different synchronized cortical activities and basic methods of evaluation of various mathematical algorithms to detect them.

  4. Cortical Network Models of Firing Rates in the Resting and Active States Predict BOLD Responses.

    Directory of Open Access Journals (Sweden)

    Maxwell R Bennett

    Full Text Available Measurements of blood oxygenation level dependent (BOLD signals have produced some surprising observations. One is that their amplitude is proportional to the entire activity in a region of interest and not just the fluctuations in this activity. Another is that during sleep and anesthesia the average BOLD correlations between regions of interest decline as the activity declines. Mechanistic explanations of these phenomena are described here using a cortical network model consisting of modules with excitatory and inhibitory neurons, taken as regions of cortical interest, each receiving excitatory inputs from outside the network, taken as subcortical driving inputs in addition to extrinsic (intermodular connections, such as provided by associational fibers. The model shows that the standard deviation of the firing rate is proportional to the mean frequency of the firing when the extrinsic connections are decreased, so that the mean BOLD signal is proportional to both as is observed experimentally. The model also shows that if these extrinsic connections are decreased or the frequency of firing reaching the network from the subcortical driving inputs is decreased, or both decline, there is a decrease in the mean firing rate in the modules accompanied by decreases in the mean BOLD correlations between the modules, consistent with the observed changes during NREM sleep and under anesthesia. Finally, the model explains why a transient increase in the BOLD signal in a cortical area, due to a transient subcortical input, gives rises to responses throughout the cortex as observed, with these responses mediated by the extrinsic (intermodular connections.

  5. Neurofeedback using real-time near-infrared spectroscopy enhances motor imagery related cortical activation.

    Directory of Open Access Journals (Sweden)

    Masahito Mihara

    Full Text Available Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS, two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients.

  6. Neural correlates of skill acquisition: decreased cortical activity during a serial interception sequence learning task.

    Science.gov (United States)

    Gobel, Eric W; Parrish, Todd B; Reber, Paul J

    2011-10-15

    Learning of complex motor skills requires learning of component movements as well as the sequential structure of their order and timing. Using a Serial Interception Sequence Learning (SISL) task, participants learned a sequence of precisely timed interception responses through training with a repeating sequence. Following initial implicit learning of the repeating sequence, functional MRI data were collected during performance of that known sequence and compared with activity evoked during novel sequences of actions, novel timing patterns, or both. Reduced activity was observed during the practiced sequence in a distributed bilateral network including extrastriate occipital, parietal, and premotor cortical regions. These reductions in evoked activity likely reflect improved efficiency in visuospatial processing, spatio-motor integration, motor planning, and motor execution for the trained sequence, which is likely supported by nondeclarative skill learning. In addition, the practiced sequence evoked increased activity in the left ventral striatum and medial prefrontal cortex, while the posterior cingulate was more active during periods of better performance. Many prior studies of perceptual-motor skill learning have found increased activity in motor areas of the frontal cortex (e.g., motor and premotor cortex, SMA) and striatal areas (e.g., the putamen). The change in activity observed here (i.e., decreased activity across a cortical network) may reflect skill learning that is predominantly expressed through more accurate performance rather than decreased reaction time. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Low-frequency hippocampal-cortical activity drives brain-wide resting-state functional MRI connectivity.

    Science.gov (United States)

    Chan, Russell W; Leong, Alex T L; Ho, Leon C; Gao, Patrick P; Wong, Eddie C; Dong, Celia M; Wang, Xunda; He, Jufang; Chan, Ying-Shing; Lim, Lee Wei; Wu, Ed X

    2017-08-15

    The hippocampus, including the dorsal dentate gyrus (dDG), and cortex engage in bidirectional communication. We propose that low-frequency activity in hippocampal-cortical pathways contributes to brain-wide resting-state connectivity to integrate sensory information. Using optogenetic stimulation and brain-wide fMRI and resting-state fMRI (rsfMRI), we determined the large-scale effects of spatiotemporal-specific downstream propagation of hippocampal activity. Low-frequency (1 Hz), but not high-frequency (40 Hz), stimulation of dDG excitatory neurons evoked robust cortical and subcortical brain-wide fMRI responses. More importantly, it enhanced interhemispheric rsfMRI connectivity in various cortices and hippocampus. Subsequent local field potential recordings revealed an increase in slow oscillations in dorsal hippocampus and visual cortex, interhemispheric visual cortical connectivity, and hippocampal-cortical connectivity. Meanwhile, pharmacological inactivation of dDG neurons decreased interhemispheric rsfMRI connectivity. Functionally, visually evoked fMRI responses in visual regions also increased during and after low-frequency dDG stimulation. Together, our results indicate that low-frequency activity robustly propagates in the dorsal hippocampal-cortical pathway, drives interhemispheric cortical rsfMRI connectivity, and mediates visual processing.

  8. Altered Cortical Activation in Adolescents With Acute Migraine: A Magnetoencephalography Study

    Science.gov (United States)

    Xiang, Jing; deGrauw, Xinyao; Korostenskaja, Milena; Korman, Abraham M.; O’Brien, Hope L.; Kabbouche, Marielle A.; Powers, Scott W.; Hershey, Andrew D.

    2013-01-01

    To quantitatively assess cortical dysfunction in pediatric migraine, 31 adolescents with acute migraine and age- and gender-matched controls were studied using a magnetoencephalography (MEG) system at a sampling rate of 6,000 Hz. Neuromagnetic brain activation was elicited by a finger-tapping task. The spectral and spatial signatures of magnetoencephalography data in 5 to 2,884 Hz were analyzed using Morlet wavelet and beamformers. Compared with controls, 31 migraine subjects during their headache attack phases (ictal) showed significantly prolonged latencies of neuromagnetic activation in 5 to 30 Hz, increased spectral power in 100 to 200 Hz, and a higher likelihood of neuromagnetic activation in the supplementary motor area, the occipital and ipsilateral sensorimotor cortices, in 2,200 to 2,800 Hz. Of the 31 migraine subjects, 16 migraine subjects during their headache-free phases (interictal) showed that there were no significant differences between interictal and control MEG data except that interictal spectral power in 100 to 200 Hz was significantly decreased. The results demonstrated that migraine subjects had significantly aberrant ictal brain activation, which can normalize interictally. The spread of abnormal ictal brain activation in both low- and high-frequency ranges triggered by movements may play a key role in the cascade of migraine attacks. Perspective This is the first study focusing on the spectral and spatial signatures of cortical dysfunction in adolescents with migraine using MEG signals in a frequency range of 5 to 2,884 Hz. This analyzing aberrant brain activation may be important for developing new therapeutic interventions for migraine in the future. PMID:23792072

  9. Thalamo-cortical activation and connectivity during response preparation in adults with persistent and remitted ADHD.

    Science.gov (United States)

    Clerkin, Suzanne M; Schulz, Kurt P; Berwid, Olga G; Fan, Jin; Newcorn, Jeffrey H; Tang, Cheuk Y; Halperin, Jeffrey M

    2013-09-01

    The neural correlates of stimulus-driven processes, such as response preparation, have been posited to be associated with the onset of attention deficit hyperactivity disorder (ADHD) while being distinct from the neural mechanisms associated with recovery. The authors tested this hypothesis in adults with remitted and persistent ADHD. Thirty-eight young adults who were diagnosed with combined-type ADHD in childhood (probands) and 32 carefully matched comparison subjects were followed longitudinally and scanned with functional MRI while performing an event-related cued reaction time task. Probands were characterized as individuals with persistent or remitted ADHD. Differences in thalamo-cortical activation and functional connectivity during response preparation between comparison subjects and probands and between individuals with persistent ADHD and those with remitted ADHD were assessed by contrasting neural activation and functional connectivity during cue or noncue events. Probands exhibited less cue-related activation than comparison subjects in the thalamus, anterior cingulate cortex, supplementary motor area, inferior parietal lobe, and dorsolateral prefrontal cortex despite similar overall patterns of activation. There were no differences in activation between individuals in the remitted ADHD group and those in the persistent ADHD group in any hypothesized regions. However, cue-related functional connectivity between the right thalamus and brainstem was greater in comparison subjects relative to probands, and cue-related connectivity was greater between the right thalamus and prefrontal regions in individuals with remitted ADHD relative to those with persistent ADHD. Decreased thalamo-cortical activation during response preparation was present in adults diagnosed with ADHD in childhood regardless of symptom remission in adulthood, and may be partly driven by less functional coordination between the brainstem and thalamus. Greater functional integration of the

  10. Brain functional near infrared spectroscopy in human infants : cerebral cortical haemodynamics coupled to neuronal activation in response to sensory stimulation

    OpenAIRE

    Bartocci, Marco

    2006-01-01

    The assessment of cortical activation in the neonatal brain is crucial in the study of brain development, as it provides precious information for how the newborn infant processes external or internal stimuli. Thus far functional studies of neonates aimed to assess cortical responses to certain external stimuli are very few, due to the lack of suitable techniques to monitor brain activity of the newborn. Near Infrared Spectroscopy (NIRS) has been found to be suitable for func...

  11. The IAEA International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO): Status, Ongoing Activities and Outlook

    International Nuclear Information System (INIS)

    Kupitz, Juergen; Depisch, Frank; Azpitarte, Osvaldo

    2004-01-01

    The IAEA General Conference (2000) invited 'all interested Member States to combine their efforts under the aegis of the IAEA in considering the issues of the nuclear fuel cycle, in particular by examining innovative and proliferation-resistant nuclear technology'. In response to this invitation, the IAEA initiated the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). The overall objectives of INPRO are to help to ensure that nuclear energy is available to contribute in fulfilling energy needs in the 21. century in a sustainable manner, and to bring together both technology holders and technology users to consider jointly the international and national actions required to achieve desired innovations in nuclear reactors and fuel cycles. In order to fulfil these objectives, the first phase of INPRO dealt with the development of a methodology to assess and compare the performance of innovative nuclear energy systems. This methodology includes the definition of a set of Basic principles, User requirements and Criteria to be met in different areas (Economics, Sustainability and environment, Safety of nuclear installations, Waste management and Proliferation resistance). The result of this phase was presented in a IAEA document (IAEA-TECDOC-1362, Guidance for the evaluation of innovative nuclear reactors and fuel cycles) issued in June 2003. In the present phase of the project, case studies are being carried out in order to validate and improve the developed methodology and the defined set of Basic principles, User requirements and Criteria. This paper shortly summarizes the results published in IAEA-TECDOC-1362 and the ongoing actions related to case studies. Finally, an outlook of INPRO activities is presented. (authors)

  12. Human cortical activity related to unilateral movements. A high resolution EEG study.

    Science.gov (United States)

    Urbano, A; Babiloni, C; Onorati, P; Babiloni, F

    1996-12-20

    In the present study a modern high resolution electroencephalography (EEG) technique was used to investigate the dynamic functional topography of human cortical activity related to simple unilateral internally triggered finger movements. The sensorimotor area (M1-S1) contralateral to the movement as well as the supplementary motor area (SMA) and to a lesser extent the ipsilateral M1-S1 were active during the preparation and execution of these movements. These findings suggest that both hemispheres may cooperate in both planning and production of simple unilateral volitional acts.

  13. Disassociation between primary motor cortical activity and movement kinematics during adaptation to reach perturbations.

    Science.gov (United States)

    Cai, X; Shimansky, Y P; Weber, D J; He, Jiping

    2004-01-01

    The relationship between movement kinematics and motor cortical activity was studied in monkeys performing a center-out reaching task during their adaptation to force perturbations applied to the wrist. The main feature of adaptive changes in movement kinematics was anticipatory deviation of hand paths in the direction opposite to that of the upcoming perturbation. We identified a group of neurons in the dorsal lateral portion of the primary motor cortex where a gradual buildup of spike activity immediately preceding the actual (in perturbation trials) or the "would-be" (in unperturbed/catch trials) perturbation onset was observed. These neurons were actively involved in the adaptation process, which was evident from the gradual increase in the amplitude of their movement-related modulation of spike activity from virtual zero and development of certain directional tuning pattern (DTP). However, the day-to-day dynamics of the kinematics adaptation was dramatically different from that of the neuronal activity. Hence, the adaptive modification of the motor cortical activity is more likely to reflect the development of the internal model of the perturbation dynamics, rather than motor instructions determining the adaptive behavior.

  14. Visuotactile motion congruence enhances gamma-band activity in visual and somatosensory cortices.

    Science.gov (United States)

    Krebber, Martin; Harwood, James; Spitzer, Bernhard; Keil, Julian; Senkowski, Daniel

    2015-08-15

    When touching and viewing a moving surface our visual and somatosensory systems receive congruent spatiotemporal input. Behavioral studies have shown that motion congruence facilitates interplay between visual and tactile stimuli, but the neural mechanisms underlying this interplay are not well understood. Neural oscillations play a role in motion processing and multisensory integration. They may also be crucial for visuotactile motion processing. In this electroencephalography study, we applied linear beamforming to examine the impact of visuotactile motion congruence on beta and gamma band activity (GBA) in visual and somatosensory cortices. Visual and tactile inputs comprised of gratings that moved either in the same or different directions. Participants performed a target detection task that was unrelated to motion congruence. While there were no effects in the beta band (13-21Hz), the power of GBA (50-80Hz) in visual and somatosensory cortices was larger for congruent compared with incongruent motion stimuli. This suggests enhanced bottom-up multisensory processing when visual and tactile gratings moved in the same direction. Supporting its behavioral relevance, GBA was correlated with shorter reaction times in the target detection task. We conclude that motion congruence plays an important role for the integrative processing of visuotactile stimuli in sensory cortices, as reflected by oscillatory responses in the gamma band. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Activity strengths of cortical glutamatergic and GABAergic neurons are correlated with transgenerational inheritance of learning ability.

    Science.gov (United States)

    Liu, Yulong; Ge, Rongjing; Zhao, Xin; Guo, Rui; Huang, Li; Zhao, Shidi; Guan, Sudong; Lu, Wei; Cui, Shan; Wang, Shirlene; Wang, Jin-Hui

    2017-12-22

    The capabilities of learning and memory in parents are presumably transmitted to their offsprings, in which genetic codes and epigenetic regulations are thought as molecular bases. As neural plasticity occurs during memory formation as cellular mechanism, we aim to examine the correlation of activity strengths at cortical glutamatergic and GABAergic neurons to the transgenerational inheritance of learning ability. In a mouse model of associative learning, paired whisker and odor stimulations led to odorant-induced whisker motion, whose onset appeared fast (high learning efficiency, HLE) or slow (low learning efficiency, LLE). HLE male and female mice, HLE female and LLE male mice as well as HLE male and LLE female mice were cross-mated to have their first generation of offsprings, filials (F1). The onset of odorant-induced whisker motion appeared a sequence of high-to-low efficiency in three groups of F1 mice that were from HLE male and female mice, HLE female and LLE male mice as well as HLE male and LLE female mice. Activities related to glutamatergic neurons in barrel cortices appeared a sequence of high-to-low strength in these F1 mice from HLE male and female mice, HLE female and LLE male mice as well as HLE male and LLE female mice. Activities related to GABAergic neurons in barrel cortices appeared a sequence of low-to-high strength in these F1 mice from HLE male and female mice, HLE female and LLE male mice as well as HLE male and LLE female mice. Neuronal activity strength was linearly correlated to learning efficiency among three groups. Thus, the coordinated activities at glutamatergic and GABAergic neurons may constitute the cellular basis for the transgenerational inheritance of learning ability.

  16. Cortical spreading depression produces a neuroprotective effect activating mitochondrial uncoupling protein-5

    Directory of Open Access Journals (Sweden)

    Viggiano E

    2016-07-01

    Full Text Available Emanuela Viggiano,1,2 Vincenzo Monda,1 Antonietta Messina,1 Fiorenzo Moscatelli,3 Anna Valenzano,3 Domenico Tafuri,4 Giuseppe Cibelli,3 Bruno De Luca,1 Giovanni Messina,1,3 Marcellino Monda1 1Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetics and Sports Medicine, Second University of Naples, Naples, 2Department of Medicine, University of Padua, Padua, 3Department of Clinical and Experimental Medicine, University of Foggia, Foggia, 4Department of Motor Sciences and Wellness, University of Naples “Parthenope”, Naples, Italy Abstract: Depression of electrocorticogram propagating over the cortex surface results in cortical spreading depression (CSD, which is probably related to the pathophysiology of stroke, epilepsy, and migraine. However, preconditioning with CSD produces neuroprotection to subsequent ischemic episodes. Such effects require the expression or activation of several genes, including neuroprotective ones. Recently, it has been demonstrated that the expression of the uncoupling proteins (UCPs 2 and 5 is amplified during brain ischemia and their expression exerts a long-term effect upon neuron protection. To evaluate the neuroprotective consequence of CSD, the expression of UCP-5 in the brain cortex was measured following CSD induction. CSD was evoked in four samples of rats, which were sacrificed after 2 hours, 4 hours, 6 hours, and 24 hours. Western blot analyses were carried out to measure UCP-5 concentrations in the prefrontal cortices of both hemispheres, and immunohistochemistry was performed to determine the localization of UCP-5 in the brain cortex. The results showed a significant elevation in UCP-5 expression at 24 hours in all cortical strata. Moreover, UCP-5 was triggered by CSD, indicating that UCP-5 production can have a neuroprotective effect. Keywords: cortical spreading depression, neuroprotective effect, uncoupling protein-5

  17. Transient and sustained cortical activity elicited by connected speech of varying intelligibility

    Directory of Open Access Journals (Sweden)

    Tiitinen Hannu

    2012-12-01

    Full Text Available Abstract Background The robustness of speech perception in the face of acoustic variation is founded on the ability of the auditory system to integrate the acoustic features of speech and to segregate them from background noise. This auditory scene analysis process is facilitated by top-down mechanisms, such as recognition memory for speech content. However, the cortical processes underlying these facilitatory mechanisms remain unclear. The present magnetoencephalography (MEG study examined how the activity of auditory cortical areas is modulated by acoustic degradation and intelligibility of connected speech. The experimental design allowed for the comparison of cortical activity patterns elicited by acoustically identical stimuli which were perceived as either intelligible or unintelligible. Results In the experiment, a set of sentences was presented to the subject in distorted, undistorted, and again in distorted form. The intervening exposure to undistorted versions of sentences rendered the initially unintelligible, distorted sentences intelligible, as evidenced by an increase from 30% to 80% in the proportion of sentences reported as intelligible. These perceptual changes were reflected in the activity of the auditory cortex, with the auditory N1m response (~100 ms being more prominent for the distorted stimuli than for the intact ones. In the time range of auditory P2m response (>200 ms, auditory cortex as well as regions anterior and posterior to this area generated a stronger response to sentences which were intelligible than unintelligible. During the sustained field (>300 ms, stronger activity was elicited by degraded stimuli in auditory cortex and by intelligible sentences in areas posterior to auditory cortex. Conclusions The current findings suggest that the auditory system comprises bottom-up and top-down processes which are reflected in transient and sustained brain activity. It appears that analysis of acoustic features occurs

  18. Curtailing effect of awakening on visual responses of cortical neurons by cholinergic activation of inhibitory circuits.

    Science.gov (United States)

    Kimura, Rui; Safari, Mir-Shahram; Mirnajafi-Zadeh, Javad; Kimura, Rie; Ebina, Teppei; Yanagawa, Yuchio; Sohya, Kazuhiro; Tsumoto, Tadaharu

    2014-07-23

    Visual responsiveness of cortical neurons changes depending on the brain state. Neural circuit mechanism underlying this change is unclear. By applying the method of in vivo two-photon functional calcium imaging to transgenic rats in which GABAergic neurons express fluorescent protein, we analyzed changes in visual response properties of cortical neurons when animals became awakened from anesthesia. In the awake state, the magnitude and reliability of visual responses of GABAergic neurons increased whereas the decay of responses of excitatory neurons became faster. To test whether the basal forebrain (BF) cholinergic projection is involved in these changes, we analyzed effects of electrical and optogenetic activation of BF on visual responses of mouse cortical neurons with in vivo imaging and whole-cell recordings. Electrical BF stimulation in anesthetized animals induced the same direction of changes in visual responses of both groups of neurons as awakening. Optogenetic activation increased the frequency of visually evoked action potentials in GABAergic neurons but induced the delayed hyperpolarization that ceased the late generation of action potentials in excitatory neurons. Pharmacological analysis in slice preparations revealed that photoactivation-induced depolarization of layer 1 GABAergic neurons was blocked by a nicotinic receptor antagonist, whereas non-fast-spiking layer 2/3 GABAergic neurons was blocked only by the application of both nicotinic and muscarinic receptor antagonists. These results suggest that the effect of awakening is mediated mainly through nicotinic activation of layer 1 GABAergic neurons and mixed nicotinic/muscarinic activation of layer 2/3 non-fast-spiking GABAergic neurons, which together curtails the visual responses of excitatory neurons. Copyright © 2014 the authors 0270-6474/14/3410122-12$15.00/0.

  19. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": ongoing research activities and third-year results

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Tosti, Fabio

    2016-04-01

    This work aims at disseminating the ongoing research activities and third-year results of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar." About 350 experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Colombia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been recognised among the running Actions as "COST Success Story" ("The Cities of Tomorrow: The Challenges of Horizon 2020," September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of

  20. The cortical activation pattern by a rehabilitation robotic hand: a functional NIRS study.

    Science.gov (United States)

    Chang, Pyung-Hun; Lee, Seung-Hee; Gu, Gwang Min; Lee, Seung-Hyun; Jin, Sang-Hyun; Yeo, Sang Seok; Seo, Jeong Pyo; Jang, Sung Ho

    2014-01-01

    Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand (uncorrected, p < 0.01). By contrast, HbR value indicated significant activation only in the hand somatotopic area of the left SM1 (uncorrected, p < 0.01). Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

  1. Resting lateralized activity predicts the cortical response and appraisal of emotions: an fNIRS study.

    Science.gov (United States)

    Balconi, Michela; Grippa, Elisabetta; Vanutelli, Maria Elide

    2015-12-01

    This study explored the effect of lateralized left-right resting brain activity on prefrontal cortical responsiveness to emotional cues and on the explicit appraisal (stimulus evaluation) of emotions based on their valence. Indeed subjective responses to different emotional stimuli should be predicted by brain resting activity and should be lateralized and valence-related (positive vs negative valence). A hemodynamic measure was considered (functional near-infrared spectroscopy). Indeed hemodynamic resting activity and brain response to emotional cues were registered when subjects (N = 19) viewed emotional positive vs negative stimuli (IAPS). Lateralized index response during resting state, LI (lateralized index) during emotional processing and self-assessment manikin rating were considered. Regression analysis showed the significant predictive effect of resting activity (more left or right lateralized) on both brain response and appraisal of emotional cues based on stimuli valence. Moreover, significant effects were found as a function of valence (more right response to negative stimuli; more left response to positive stimuli) during emotion processing. Therefore, resting state may be considered a predictive marker of the successive cortical responsiveness to emotions. The significance of resting condition for emotional behavior was discussed. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  2. Chronic post-stroke oropharyngeal dysphagia is associated with impaired cortical activation to pharyngeal sensory inputs.

    Science.gov (United States)

    Cabib, C; Ortega, O; Vilardell, N; Mundet, L; Clavé, P; Rofes, L

    2017-11-01

    The role of afferent sensory pathways in the pathophysiology of post-stroke oropharyngeal dysphagia is not known. We hypothesized that patients with chronic post-stroke dysphagia (PSD) would show impaired sensory cortical activation in the ipsilesional hemisphere. We studied 28 chronic unilateral post-stroke patients [17 PSD and 11 post-stroke non-dysphagic patients (PSnD)] and 11 age-matched healthy volunteers. Event-related sensory-evoked potentials to pharyngeal stimulation (pSEP) and sensory thresholds were assessed. We analyzed pSEP peak latency and amplitude (N1, P1, N2 and P2), and neurotopographic stroke characteristics from brain magnetic resonance imaging. Healthy volunteers presented a highly symmetric bihemispheric cortical pattern of brain activation at centroparietal areas (N1-P1 and N2-P2) to pharyngeal stimuli. In contrast, an asymmetric pattern of reduced ipsilesional activation was found in PSD (N2-P2; P = 0.026) but not in PSnD. PSD presented impaired safety of swallow (penetration-aspiration score: 4.3 ± 1.6), delayed laryngeal vestibule closure (360.0 ± 70.0 ms) and higher National Institute of Health Stroke Scale (7.0 ± 6.2 vs. 1.9 ± 1.4, P = 0.001) and Fazekas scores (3.0 ± 1.4 vs. 2.0 ± 1.1; P dysphagia is associated with stroke severity and degree of leukoaraoisis. Impaired conduction and cortical integration of pharyngeal sensory inputs at stroke site are key features of chronic PSD. These findings highlight the role of sensory pathways in the pathophysiology of post-stroke oropharyngeal dysphagia and offer a potential target for future treatments. © 2017 EAN.

  3. The IAEA international project on innovative nuclear reactors and fuel cycles (INPRO): Status, ongoing activities and outlook

    International Nuclear Information System (INIS)

    Kupitz, J.; Depisch, F.; Khorochev, M.

    2004-01-01

    this phase was presented in a IAEA document (IAEA-TECDOC-1362, Guidance for the evaluation of innovative nuclear reactors and fuel cycles) issued in June 2003. In the present phase of the project, case studies are being carried out in order to validate and refine the developed methodology including the set of Basic principles, User requirements, Criteria and the judgement procedure. This paper shortly summarizes the results published in IAEA-TECDOC-1362 and the ongoing actions related to validation of INPRO Methodology via case studies. Finally, an outlook of INPRO activities is presented. (authors)

  4. State-dependent intrinsic predictability of cortical network dynamics.

    Directory of Open Access Journals (Sweden)

    Leila Fakhraei

    Full Text Available The information encoded in cortical circuit dynamics is fleeting, changing from moment to moment as new input arrives and ongoing intracortical interactions progress. A combination of deterministic and stochastic biophysical mechanisms governs how cortical dynamics at one moment evolve from cortical dynamics in recently preceding moments. Such temporal continuity of cortical dynamics is fundamental to many aspects of cortex function but is not well understood. Here we study temporal continuity by attempting to predict cortical population dynamics (multisite local field potential based on its own recent history in somatosensory cortex of anesthetized rats and in a computational network-level model. We found that the intrinsic predictability of cortical dynamics was dependent on multiple factors including cortical state, synaptic inhibition, and how far into the future the prediction extends. By pharmacologically tuning synaptic inhibition, we obtained a continuum of cortical states with asynchronous population activity at one extreme and stronger, spatially extended synchrony at the other extreme. Intermediate between these extremes we observed evidence for a special regime of population dynamics called criticality. Predictability of the near future (10-100 ms increased as the cortical state was tuned from asynchronous to synchronous. Predictability of the more distant future (>1 s was generally poor, but, surprisingly, was higher for asynchronous states compared to synchronous states. These experimental results were confirmed in a computational network model of spiking excitatory and inhibitory neurons. Our findings demonstrate that determinism and predictability of network dynamics depend on cortical state and the time-scale of the dynamics.

  5. Effects of Cortical Spreading Depression on Synaptic Activity, Blood Flow and Oxygen Consumption in Rat Cerebral Cortex

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard

    2010-01-01

    As the title of this thesis indicates I have during my PhD studied the effects of cortical spreading depression (CSD) on synaptic activity, blood flow and oxygen consumption in rat cerebral cortex. This was performed in vivo using an open cranial window approach in anesthetized rats. I applied...... parameters of the whisker/infraorbital nerve etwork (IO) targeting the same cortical area. We tested the hypothesis that the relation between increases in CBF and CMRO2 evoked by stimulation and synaptic activity differed for the two activated networks and that activation of two distinct networks activate...

  6. Cognitively Engaging Activity is Associated with Greater Cortical and Subcortical Volumes

    Directory of Open Access Journals (Sweden)

    Talia R. Seider

    2016-05-01

    Full Text Available As the population ages and dementia becomes a growing healthcare concern, it is increasingly important to identify targets for intervention to delay or attenuate cognitive decline. Research has shown that the most successful interventions aim at altering lifestyle factors. Thus, this study examined how involvement in physical, cognitive, and social activity is related to brain structure in older adults. Sixty-five adults (mean age = 71.4 years, standard deviation = 8.9 received the Community Healthy Activities Model Program for Seniors (CHAMPS, a questionnaire that polls everyday activities in which older adults may be involved, and also underwent structural magnetic resonance imaging. Stepwise regression with backwards selection was used to predict weekly time spent in either social, cognitive, light physical, or heavy physical activity from the volume of one of the cortical or subcortical regions of interest (corrected by intracranial volume as well as age, education, and gender as control variables. Regressions revealed that more time spent in cognitive activity was associated with greater volumes of all brain regions studied: total cortex (β = .289, p = .014, frontal (β = .276, p = .019, parietal (β = .305, p = .009, temporal (β = .275, p = .020, and occipital (β = .256, p = .030 lobes, and thalamus (β = .310, p = .010, caudate (β = .233, p = .049, hippocampus (β = .286, p = .017, and amygdala (β = .336, p = .004. These effects remained even after accounting for the positive association between cognitive activity and education. No other activity variable was associated with brain volumes. Results indicate that time spent in cognitively engaging activity is associated with greater cortical and subcortical brain volume. Findings suggest that interventions aimed at increasing levels of cognitive activity may delay cognitive consequences of aging and decrease the risk of developing dementia.

  7. The cortical activation pattern by a rehabilitation robotic hand : A functional NIRS study

    Directory of Open Access Journals (Sweden)

    Pyung Hun eChang

    2014-02-01

    Full Text Available Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS, we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin(HbO, deoxy-hemoglobin(HbR and total-hemoglobin(HbT in five regions of interest: the primary sensory-motor cortex (SM1, hand somatotopy of the contralateral SM1, supplementary motor area (SMA, premotor cortex (PMC, and prefrontal cortex (PFC. Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand(uncorrected, pConclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

  8. High social desirability and prefrontal cortical activity in cancer patients: a preliminary study.

    Science.gov (United States)

    Tashiro, Manabu; Juengling, Freimut D; Moser, Ernst; Reinhardt, Michael J; Kubota, Kazuo; Yanai, Kazuhiko; Sasaki, Hidetada; Nitzsche, Egbert U; Kumano, Hiroaki; Itoh, Masatoshi

    2003-04-01

    Social desirability is sometimes associated with poor prognosis in cancer patients. Psycho-neuro-immune interaction has been hypothesized as an underlying mechanism of the negative clinical outcome. Purpose of this study was to examine possible effects of high social desirability on the regional brain activity in patients with malignant diseases. Brain metabolism of 16 patients with various malignant diseases was measured by PET with 18F-fluorodeoxyglucose (FDG). Patients were divided into 2 groups using median split on Marlowe & Crown's Social Desirability Scale (MC), controlling for age, gender, and for severity of depression and anxiety, the possible two major influential factors. A group comparison of the regional cerebral activity was calculated on a voxel-by-voxel basis using statistical parametric mapping (SPM). The subgroup comparison showed that the high social desirability was associated with relatively increased metabolism in the cortical regions in the prefrontal, temporal and occipital lobes as well as in the anterior cingulate gyrus. High social desirability seems to be associated with increased activity in the prefrontal and other cortical areas. The finding is in an accordance with previous studies that demonstrated an association between prefrontal damage and anti-social behavior. Functional neuroimaging seems to be useful not only for psychiatric evaluation of major factors such as depression and anxiety but also for further psychosocial factors in cancer patients.

  9. Personality Traits and Cortical Activity Affect Gambling Behavior in Parkinson's Disease.

    Science.gov (United States)

    Balconi, Michela; Siri, Chiara; Meucci, Nicoletta; Pezzoli, Gianni; Angioletti, Laura

    2018-03-26

    Pathological gambling (PG) in Parkinson's disease (PD) manifests as a persistent and uncontrollable gambling behavior, characterized by dysfunctional decision-making and emotional impairment related to high-risk decisions. The aim of this study was to explore the relationship between personality traits and prefrontal cortex activity in PD patients with or without PG. Thus, hemodynamic cortical activity measured by functional near-infrared spectroscopy (fNIRS) and Iowa Gambling Task (IGT) performance were recorded in forty-six PD patients, divided into three groups according to their gambling status: PD patients with active gambling behavior (PDG); PD patients who remitted from PG (PDNG); and a control group (CG) composed by patients with PD only. Results indicates that gambling behavior in PD patients is strongly predictive of dysfunctional cognitive strategy; affecting anomalous cortical response with a left hemispheric unbalance in dorsal areas; and it is related to more reward sensitivity than impulsivity personality components. PDG patients differed from PDNG and CG from both behavioral and brain response to decision-making. Overall, these effects confirm a pathological condition related to cognitive and emotional aspects which makes the patients with PGD victims of their dysfunctional behavior.

  10. Cortical ensemble activity increasingly predicts behaviour outcomes during learning of a motor task

    Science.gov (United States)

    Laubach, Mark; Wessberg, Johan; Nicolelis, Miguel A. L.

    2000-06-01

    When an animal learns to make movements in response to different stimuli, changes in activity in the motor cortex seem to accompany and underlie this learning. The precise nature of modifications in cortical motor areas during the initial stages of motor learning, however, is largely unknown. Here we address this issue by chronically recording from neuronal ensembles located in the rat motor cortex, throughout the period required for rats to learn a reaction-time task. Motor learning was demonstrated by a decrease in the variance of the rats' reaction times and an increase in the time the animals were able to wait for a trigger stimulus. These behavioural changes were correlated with a significant increase in our ability to predict the correct or incorrect outcome of single trials based on three measures of neuronal ensemble activity: average firing rate, temporal patterns of firing, and correlated firing. This increase in prediction indicates that an association between sensory cues and movement emerged in the motor cortex as the task was learned. Such modifications in cortical ensemble activity may be critical for the initial learning of motor tasks.

  11. Metabolic and hemodynamic activation of postischemic rat brain by cortical spreading depression.

    Science.gov (United States)

    Kocher, M

    1990-07-01

    Following transient ischemia of the brain, the coupling between somatosensory activation and the hemodynamic-metabolic response is abolished for a certain period despite the partial recovery of somatosensory evoked responses. To determine whether this disturbance is due to alterations of the stimulus-induced neuronal excitation or to a breakdown of the coupling mechanisms, cortical spreading depression was used as a metabolic stimulus in rats before and after ischemia. Adult rats were subjected to 30 min of global forebrain ischemia and 3-6 h of recirculation. EEG, cortical direct current (DC) potential, and laser-Doppler flow were continuously recorded. Local CBF (LCBF), local CMRglc (LCMRglc), regional tissue contents of ATP, glucose, and lactate, and regional pH were determined by quantitative autoradiography, substrate-induced bioluminescence, and fluorometry. Amplitude and frequency of the DC shifts did not differ between groups. In control animals, spreading depression induced a 77% rise in cortical glucose consumption, a 66% rise in lactate content, and a drop in tissue pH of 0.3 unit. ATP and glucose contents were not depleted. During the passage of DC shifts, transient increases (less than 2 min) in laser-Doppler flow were observed, followed by a post-spreading depression hypoperfusion. A comparable although less expressed pattern of hemodynamic and metabolic changes was observed in the postischemic rats. Although baseline LCMRglc was depressed after ischemia, it was activated 47% during spreading depression. Lactate increased by 26%, pH decreased by 0.3 unit, and ATP and glucose remained unchanged. The extent of the transient increase in laser-Doppler flow did not differ from that of the control group, and a post-spreading depression hypoperfusion was also found.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Mapping the fine structure of cortical activity with different micro-ECoG electrode array geometries

    Science.gov (United States)

    Wang, Xi; Gkogkidis, C. Alexis; Iljina, Olga; Fiederer, Lukas D. J.; Henle, Christian; Mader, Irina; Kaminsky, Jan; Stieglitz, Thomas; Gierthmuehlen, Mortimer; Ball, Tonio

    2017-10-01

    Objective. Innovations in micro-electrocorticography (µECoG) electrode array manufacturing now allow for intricate designs with smaller contact diameters and/or pitch (i.e. inter-contact distance) down to the sub-mm range. The aims of the present study were: (i) to investigate whether frequency ranges up to 400 Hz can be reproducibly observed in µECoG recordings and (ii) to examine how differences in topographical substructure between these frequency bands and electrode array geometries can be quantified. We also investigated, for the first time, the influence of blood vessels on signal properties and assessed the influence of cortical vasculature on topographic mapping. Approach. The present study employed two µECoG electrode arrays with different contact diameters and inter-contact distances, which were used to characterize neural activity from the somatosensory cortex of minipigs in a broad frequency range up to 400 Hz. The analysed neural data were recorded in acute experiments under anaesthesia during peripheral electrical stimulation. Main results. We observed that µECoG recordings reliably revealed multi-focal cortical somatosensory response patterns, in which response peaks were often less than 1 cm apart and would thus not have been resolvable with conventional ECoG. The response patterns differed by stimulation site and intensity, they were distinct for different frequency bands, and the results of functional mapping proved independent of cortical vascular. Our analysis of different frequency bands exhibited differences in the number of activation peaks in topographical substructures. Notably, signal strength and signal-to-noise ratios differed between the two electrode arrays, possibly due to their different sensitivity for variations in spatial patterns and signal strengths. Significance. Our findings that the geometry of µECoG electrode arrays can strongly influence their recording performance can help to make informed decisions that maybe

  13. An anterior-to-posterior shift in midline cortical activity in schizophrenia during self-reflection.

    Science.gov (United States)

    Holt, Daphne J; Cassidy, Brittany S; Andrews-Hanna, Jessica R; Lee, Su Mei; Coombs, Garth; Goff, Donald C; Gabrieli, John D; Moran, Joseph M

    2011-03-01

    Deficits in social cognition, including impairments in self-awareness, contribute to the overall functional disability associated with schizophrenia. Studies in healthy subjects have shown that social cognitive functions, including self-reflection, rely on the medial prefrontal cortex (mPFC) and posterior cingulate gyrus, and these regions exhibit highly correlated activity during "resting" states. In this study, we tested the hypothesis that patients with schizophrenia show dysfunction of this network during self-reflection and that this abnormal activity is associated with changes in the strength of resting-state correlations between these regions. Activation during self-reflection and control tasks was measured with functional magnetic resonance imaging in 19 patients with schizophrenia and 20 demographically matched control subjects. In addition, the resting-state functional connectivity of midline cortical areas showing abnormal self-reflection-related activation in schizophrenia was measured. Compared with control subjects, the schizophrenia patients demonstrated lower activation of the right ventral mPFC and greater activation of the mid/posterior cingulate gyri bilaterally during self-reflection, relative to a control task. A similar pattern was seen during overall social reflection. In addition, functional connectivity between the portion of the left mid/posterior cingulate gyrus showing abnormally elevated activity during self-reflection in schizophrenia, and the dorsal anterior cingulate gyrus was lower in the schizophrenia patients compared with control subjects. Schizophrenia is associated with an anterior-to-posterior shift in introspection-related activation, as well as changes in functional connectivity, of the midline cortex. These findings provide support for the hypothesis that aberrant midline cortical function contributes to social cognitive impairment in schizophrenia. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier

  14. The number of supports does not modify the electrical cortical activity during balance tasks.

    Directory of Open Access Journals (Sweden)

    Daniel Collado-Mateo

    2017-08-01

    Full Text Available Aims: The objective was to evaluate the electrical cortical activity during two static and two dynamic tasks, comparing between tasks with single support tasks and tasks with two feet on the platform. Settings and Design: Sixteen young males participated in this cross-sectional study. Methods and Material: Electrical cortical activity was assessed using the Enobio device. Two static and two dynamic tasks were performed, all of them on the Biodex Balance System device. Statistical analysis used: Mean power spectrum for the Alpha band was analyzed. The Wilcoxon signed rank test was used to compare tasks with one single support and tasks with the two feet on the platform. Results: No significant difference was observed when comparing the balance tasks. Conclusions: The number of supports did not significantly modify the EEG signal in the alpha band. However, cognitive demands in the single support dynamic task seemed to be somewhat higher compared with the rest of the tasks. These results may be relevant to design future programs based on dual task.

  15. Gaming is related to enhanced working memory performance and task-related cortical activity.

    Science.gov (United States)

    Moisala, M; Salmela, V; Hietajärvi, L; Carlson, S; Vuontela, V; Lonka, K; Hakkarainen, K; Salmela-Aro, K; Alho, K

    2017-01-15

    Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13-24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured using functional magnetic resonance imaging (fMRI). The results revealed that the extent of daily gaming activity was related to enhancements in both performance accuracy and speed during the most demanding (2-back) level of the working memory task. This improved working memory performance was accompanied by enhanced recruitment of a fronto-parietal cortical network, especially the dorsolateral prefrontal cortex. In contrast, during the less demanding (1-back) level of the task, gaming was associated with decreased activity in the same cortical regions. Our results suggest that a greater degree of daily gaming experience is associated with better working memory functioning and task difficulty-dependent modulation in fronto-parietal brain activity already in adolescence and even when non-expert gamers are studied. The direction of causality within this association cannot be inferred with certainty due to the correlational nature of the current study. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar:" ongoing research activities and mid-term results

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2015-04-01

    This work aims at presenting the ongoing activities and mid-term results of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar.' Almost three hundreds experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been praised among the running Actions as 'COST Success Story' ('The Cities of Tomorrow: The Challenges of Horizon 2020,' September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects

  17. Associations of limbic-affective brain activity and severity of ongoing chronic arthritis pain are explained by trait anxiety

    Directory of Open Access Journals (Sweden)

    William J. Cottam

    2016-01-01

    Full Text Available Functional magnetic resonance imaging studies (fMRI have transformed our understanding of central processing of evoked pain but the typically used block and event-related designs are not best suited to the study of ongoing pain. Here we used arterial spin labelling (ASL for cerebral blood flow mapping to characterise the neural correlates of perceived intensity of osteoarthritis (OA pain and its interrelation with negative affect. Twenty-six patients with painful knee OA and twenty-seven healthy controls underwent pain phenotyping and ASL MRI at 3T. Intensity of OA pain correlated positively with blood flow in the anterior mid-cingulate cortex (aMCC, subgenual cingulate cortex (sgACC, bilateral hippocampi, bilateral amygdala, left central operculum, mid-insula, putamen and the brainstem. Additional control for trait anxiety scores reduced the pain-CBF association to the aMCC, whilst pain catastrophizing scores only explained some of the limbic correlations. In conclusion, we found that neural correlates of reported intensity of ongoing chronic pain intensity mapped to limbic-affective circuits, and that the association pattern apart from aMCC was explained by trait anxiety thus highlighting the importance of aversiveness in the experience of clinical pain.

  18. Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents.

    Science.gov (United States)

    Seibt, Julie; Richard, Clément J; Sigl-Glöckner, Johanna; Takahashi, Naoya; Kaplan, David I; Doron, Guy; de Limoges, Denis; Bocklisch, Christina; Larkum, Matthew E

    2017-09-25

    How sleep influences brain plasticity is not known. In particular, why certain electroencephalographic (EEG) rhythms are linked to memory consolidation is poorly understood. Calcium activity in dendrites is known to be necessary for structural plasticity changes, but this has never been carefully examined during sleep. Here, we report that calcium activity in populations of neocortical dendrites is increased and synchronised during oscillations in the spindle range in naturally sleeping rodents. Remarkably, the same relationship is not found in cell bodies of the same neurons and throughout the cortical column. Spindles during sleep have been suggested to be important for brain development and plasticity. Our results provide evidence for a physiological link of spindles in the cortex specific to dendrites, the main site of synaptic plasticity.Different stages of sleep, marked by particular electroencephalographic (EEG) signatures, have been linked to memory consolidation, but underlying mechanisms are poorly understood. Here, the authors show that dendritic calcium synchronisation correlates with spindle-rich sleep phases.

  19. Plasticity during Sleep Is Linked to Specific Regulation of Cortical Circuit Activity

    Directory of Open Access Journals (Sweden)

    Niels Niethard

    2017-09-01

    Full Text Available Sleep is thought to be involved in the regulation of synaptic plasticity in two ways: by enhancing local plastic processes underlying the consolidation of specific memories and by supporting global synaptic homeostasis. Here, we briefly summarize recent structural and functional studies examining sleep-associated changes in synaptic morphology and neural excitability. These studies point to a global down-scaling of synaptic strength across sleep while a subset of synapses increases in strength. Similarly, neuronal excitability on average decreases across sleep, whereas subsets of neurons increase firing rates across sleep. Whether synapse formation and excitability is down or upregulated across sleep appears to partly depend on the cell’s activity level during wakefulness. Processes of memory-specific upregulation of synapse formation and excitability are observed during slow wave sleep (SWS, whereas global downregulation resulting in elimination of synapses and decreased neural firing is linked to rapid eye movement sleep (REM sleep. Studies of the excitation/inhibition balance in cortical circuits suggest that both processes are connected to a specific inhibitory regulation of cortical principal neurons, characterized by an enhanced perisomatic inhibition via parvalbumin positive (PV+ cells, together with a release from dendritic inhibition by somatostatin positive (SOM+ cells. Such shift towards increased perisomatic inhibition of principal cells appears to be a general motif which underlies the plastic synaptic changes observed during sleep, regardless of whether towards up or downregulation.

  20. Cortical activity during cued picture naming predicts individual differences in stuttering frequency.

    Science.gov (United States)

    Mock, Jeffrey R; Foundas, Anne L; Golob, Edward J

    2016-09-01

    Developmental stuttering is characterized by fluent speech punctuated by stuttering events, the frequency of which varies among individuals and contexts. Most stuttering events occur at the beginning of an utterance, suggesting neural dynamics associated with stuttering may be evident during speech preparation. This study used EEG to measure cortical activity during speech preparation in men who stutter, and compared the EEG measures to individual differences in stuttering rate as well as to a fluent control group. Each trial contained a cue followed by an acoustic probe at one of two onset times (early or late), and then a picture. There were two conditions: a speech condition where cues induced speech preparation of the picture's name and a control condition that minimized speech preparation. Across conditions stuttering frequency correlated to cue-related EEG beta power and auditory ERP slow waves from early onset acoustic probes. The findings reveal two new cortical markers of stuttering frequency that were present in both conditions, manifest at different times, are elicited by different stimuli (visual cue, auditory probe), and have different EEG responses (beta power, ERP slow wave). The cue-target paradigm evoked brain responses that correlated to pre-experimental stuttering rate. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Human cortical activity evoked by the assignment of authenticity when viewing works of art

    Directory of Open Access Journals (Sweden)

    Mengfei eHuang

    2011-11-01

    Full Text Available 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 aesthetic 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 psychophysiological 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 aesthetic judgments are multi-faceted and multi-dimensional in nature.

  2. Consequences of Laughter Upon Trunk Compression and Cortical Activation: Linear and Polynomial Relations

    Science.gov (United States)

    Svebak, Sven

    2016-01-01

    Results from two studies of biological consequences of laughter are reported. A proposed inhibitory brain mechanism was tested in Study 1. It aims to protect against trunk compression that can cause health hazards during vigorous laughter. Compression may be maximal during moderate durations and, for protective reasons, moderate in enduring vigorous laughs. Twenty-five university students volunteered to see a candid camera film. Laughter responses (LR) and the superimposed ha-responses were operationally assessed by mercury-filled strain gauges strapped around the trunk. On average, the thorax compression amplitudes exceeded those of the abdomen, and greater amplitudes were seen in the males than in the females after correction for resting trunk circumference. Regression analyses supported polynomial relations because medium LR durations were associated with particularly high thorax amplitudes. In Study 2, power changes were computed in the beta and alpha EEG frequency bands of the parietal cortex from before to after exposure to the comedy “Dinner for one” in 56 university students. Highly significant linear relations were calculated between the number of laughs and post-exposure cortical activation (increase of beta, decrease of alpha) due to high activation after frequent laughter. The results from Study 1 supported the hypothesis of a protective brain mechanism that is activated during long LRs to reduce the risk of harm to vital organs in the trunk cavity. The results in Study 2 supported a linear cortical activation and, thus, provided evidence for a biological correlate to the subjective experience of mental refreshment after laughter. PMID:27547260

  3. Valence of physical stimuli, not housing conditions, affects behaviour and frontal cortical brain activity in sheep.

    Science.gov (United States)

    Vögeli, Sabine; Lutz, Janika; Wolf, Martin; Wechsler, Beat; Gygax, Lorenz

    2014-07-01

    Modulation of short-term emotions by long-term mood is little understood but relevant to understand the affective system and of importance in respect to animal welfare: a negative mood might taint experiences, whilst a positive mood might alleviate single negative events. To induce different mood states in sheep housing conditions were varied. Fourteen ewes were group-housed in an unpredictable, stimulus-poor and 15 ewes in a predictable, stimulus-rich environment. Sheep were tested individually for mood in a behavioural cognitive bias paradigm. Also, their reactions to three physical stimuli thought to differ in their perceived valence were observed (negative: pricking, intermediate: slight pressure, positive: kneading). General behaviour, activity, ear movements and positions, and haemodynamic changes in the cortical brain were recorded during stimulations. Generalised mixed-effects models and model probabilities based on the BIC (Bayesian information criterion) were used. Only weak evidence for mood difference was found. Sheep from the unpredictable, stimulus-poor housing condition had a somewhat more negative cognitive bias, showed slightly more aversive behaviour, were slightly more active and moved their ears somewhat more. Sheep most clearly differentiated the negative from the intermediate and positive stimulus in that they exhibited more aversive behaviour, less nibbling, were more active, showed more ear movements, more forward ear postures, fewer backward ear postures, and a stronger decrease in deoxyhaemoglobin when subjected to the negative stimulus. In conclusion, sheep reacted towards stimuli according to their presumed valence but their mood was not strongly influenced by housing conditions. Therefore, behavioural reactions and cortical brain activity towards the stimuli were hardly modulated by housing conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Investigating the effects of a sensorimotor rhythm-based BCI training on the cortical activity elicited by mental imagery

    Science.gov (United States)

    Toppi, J.; Risetti, M.; Quitadamo, L. R.; Petti, M.; Bianchi, L.; Salinari, S.; Babiloni, F.; Cincotti, F.; Mattia, D.; Astolfi, L.

    2014-06-01

    Objective. It is well known that to acquire sensorimotor (SMR)-based brain-computer interface (BCI) control requires a training period before users can achieve their best possible performances. Nevertheless, the effect of this training procedure on the cortical activity related to the mental imagery ability still requires investigation to be fully elucidated. The aim of this study was to gain insights into the effects of SMR-based BCI training on the cortical spectral activity associated with the performance of different mental imagery tasks. Approach. Linear cortical estimation and statistical brain mapping techniques were applied on high-density EEG data acquired from 18 healthy participants performing three different mental imagery tasks. Subjects were divided in two groups, one of BCI trained subjects, according to their previous exposure (at least six months before this study) to motor imagery-based BCI training, and one of subjects who were naive to any BCI paradigms. Main results. Cortical activation maps obtained for trained and naive subjects indicated different spectral and spatial activity patterns in response to the mental imagery tasks. Long-term effects of the previous SMR-based BCI training were observed on the motor cortical spectral activity specific to the BCI trained motor imagery task (simple hand movements) and partially generalized to more complex motor imagery task (playing tennis). Differently, mental imagery with spatial attention and memory content could elicit recognizable cortical spectral activity even in subjects completely naive to (BCI) training. Significance. The present findings contribute to our understanding of BCI technology usage and might be of relevance in those clinical conditions when training to master a BCI application is challenging or even not possible.

  5. Locally formed dopamine inhibits Na+-K+-ATPase activity in rat renal cortical tubule cells

    International Nuclear Information System (INIS)

    Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J.

    1988-01-01

    Dopamine, generated locally from L-dopa, inhibits Na + -K + -ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na + -K + -ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate (Qo 2 ) and 86 Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive Qo 2 or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive Qo 2 in a concentration-dependent manner, with half-maximal inhibition (K 0.5 ) of 5 x 10 -7 M and a maximal inhibition of 14.1 ± 1.5% at 10 -4 M. L-Dopa also blunted the nystatin-stimulated Qo 2 in a concentration-dependent manner, indicating the L-dopa directly inhibits Na + -K + -ATPase activity and not sodium entry. Ouabain-sensitive 86 Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive Qo 2 and 86 Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive Qo 2 at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na + -K + -ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner

  6. Cognitive context determines dorsal premotor cortical activity during hand movement in patients after stroke.

    Science.gov (United States)

    Dennis, Andrea; Bosnell, Rose; Dawes, Helen; Howells, Ken; Cockburn, Janet; Kischka, Udo; Matthews, Paul; Johansen-Berg, Heidi

    2011-04-01

    Stroke patients often have difficulties in simultaneously performing a motor and cognitive task. Functional imaging studies have shown that movement of an affected hand after stroke is associated with increased activity in multiple cortical areas, particularly in the contralesional hemisphere. We hypothesized patients for whom executing simple movements demands greater selective attention will show greater brain activity during movement. Eight chronic stroke patients performed a behavioral interference test using a visuo-motor tracking with and without a simultaneous cognitive task. The magnitude of behavioral task decrement under cognitive motor interference (CMI) conditions was calculated for each subject. Functional MRI was used to assess brain activity in the same patients during performance of a visuo-motor tracking task alone; correlations between CMI score and movement-related brain activation were then explored. Movement-related activation in the dorsal precentral gyrus of the contralesional hemisphere correlated strongly and positively with CMI score (r(2) at peak voxel=0.92; Pstroke. The results emphasize the importance of considering cognitive context when interpreting brain activity patterns and provide a rationale for further evaluation of integrated cognitive and movement interventions for rehabilitation in stroke.

  7. Human motor cortical activity recorded with Micro-ECoG electrodes, during individual finger movements.

    Science.gov (United States)

    Wang, W; Degenhart, A D; Collinger, J L; Vinjamuri, R; Sudre, G P; Adelson, P D; Holder, D L; Leuthardt, E C; Moran, D W; Boninger, M L; Schwartz, A B; Crammond, D J; Tyler-Kabara, E C; Weber, D J

    2009-01-01

    In this study human motor cortical activity was recorded with a customized micro-ECoG grid during individual finger movements. The quality of the recorded neural signals was characterized in the frequency domain from three different perspectives: (1) coherence between neural signals recorded from different electrodes, (2) modulation of neural signals by finger movement, and (3) accuracy of finger movement decoding. It was found that, for the high frequency band (60-120 Hz), coherence between neighboring micro-ECoG electrodes was 0.3. In addition, the high frequency band showed significant modulation by finger movement both temporally and spatially, and a classification accuracy of 73% (chance level: 20%) was achieved for individual finger movement using neural signals recorded from the micro-ECoG grid. These results suggest that the micro-ECoG grid presented here offers sufficient spatial and temporal resolution for the development of minimally-invasive brain-computer interface applications.

  8. Cortical activity and children's rituals, habits and other repetitive behavior: a visual P300 study.

    Science.gov (United States)

    Evans, David W; Maliken, Ashley

    2011-10-10

    This study examines the link between children's repetitive, ritualistic, behavior and cortical brain activity. Twelve typically developing children between the ages of 6 and 12 years were administered two visual P300, oddball tasks with a 32-electrode electroencephalogram (EEG) system. One of the oddball tasks was specifically designed to reflect sensitivity to asymmetry, a phenomenon common in children and in a variety of disorders involving compulsive behavior. Parents completed the Childhood Routines Inventory. Children's repetitive, compulsive-like behaviors were strongly associated with faster processing of an asymmetrical target stimulus, even when accounting for their P300 latencies on a control task. The research punctuates the continuity between observed brain-behavior links in clinical disorders such as OCD and autism spectrum disorders, and normative variants of repetitive behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Gender specific changes in cortical activation patterns during exposure to artificial gravity

    Science.gov (United States)

    Schneider, Stefan; Robinson, Ryan; Smith, Craig; von der Wiesche, Melanie; Goswami, Nandu

    2014-11-01

    Keeping astronauts healthy during long duration spaceflight remains a challenge. Artificial gravity (AG) generated by a short arm human centrifuges (SAHC) is proposed as the next generation of integrated countermeasure devices that will allow human beings to safely spend extended durations in space, although comparatively little is known about any psychological side effects of AG on brain function. 16 participants (8 male and 8 female, GENDER) were exposed to 10 min at a baseline gravitational load (G-Load) of +.03 Gz, then 10 min at +.6 Gz for females and +.8 Gz for males, before being exposed to increasing levels of AG in a stepped manner by increasing the acceleration by +.1 Gz every 3 min until showing signs of pre-syncope. EEG recordings were taken of brain activity during 2 min time periods at each AG level. Analysing the results of the mixed total population of participants by two way ANOVA, a significant effect of centrifugation on alpha and beta activity was found (p<.01). Furthermore results revealed a significant interaction between G-LOAD and GENDER alpha-activity (p<.01), but not for beta-activity. Although the increase in alpha and beta activity with G-LOAD does not reflect a general model of cortical arousal and therefore cannot support previous findings reporting that AG may be a cognitively arousing environment, the gender specific responses identified in this study may have wider implications for EEG and AG research.

  10. Nanomolar bifenthrin alters synchronous Ca2+ oscillations and cortical neuron development independent of sodium channel activity.

    Science.gov (United States)

    Cao, Zhengyu; Cui, Yanjun; Nguyen, Hai M; Jenkins, David Paul; Wulff, Heike; Pessah, Isaac N

    2014-04-01

    Bifenthrin, a relatively stable type I pyrethroid that causes tremors and impairs motor activity in rodents, is broadly used. We investigated whether nanomolar bifenthrin alters synchronous Ca(2+) oscillations (SCOs) necessary for activity-dependent dendritic development. Primary mouse cortical neurons were cultured 8 or 9 days in vitro (DIV), loaded with the Ca(2+) indicator Fluo-4, and imaged using a Fluorescence Imaging Plate Reader Tetra. Acute exposure to bifenthrin rapidly increased the frequency of SCOs by 2.7-fold (EC50 = 58 nM) and decreased SCO amplitude by 36%. Changes in SCO properties were independent of modifications in voltage-gated sodium channels since 100 nM bifenthrin had no effect on the whole-cell Na(+) current, nor did it influence neuronal resting membrane potential. The L-type Ca(2+) channel blocker nifedipine failed to ameliorate bifenthrin-triggered SCO activity. By contrast, the metabotropic glutamate receptor (mGluR)5 antagonist MPEP [2-methyl-6-(phenylethynyl)pyridine] normalized bifenthrin-triggered increase in SCO frequency without altering baseline SCO activity, indicating that bifenthrin amplifies mGluR5 signaling independent of Na(+) channel modification. Competitive [AP-5; (-)-2-amino-5-phosphonopentanoic acid] and noncompetitive (dizocilpine, or MK-801 [(5S,10R)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate]) N-methyl-d-aspartate antagonists partially decreased both basal and bifenthrin-triggered SCO frequency increase. Bifenthrin-modified SCO rapidly enhanced the phosphorylation of cAMP response element-binding protein (CREB). Subacute (48 hours) exposure to bifenthrin commencing 2 DIV-enhanced neurite outgrowth and persistently increased SCO frequency and reduced SCO amplitude. Bifenthrin-stimulated neurite outgrowth and CREB phosphorylation were dependent on mGluR5 activity since MPEP normalized both responses. Collectively these data identify a new mechanism by which bifenthrin potently alters Ca(2

  11. Flow velocity change in the cortical vein during motor activation and its effect on functional brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kazuhiro [Kyoto Prefectural Univ. of Medicine (Japan)

    1998-06-01

    On the brain functional magnetic resonance imaging (fMRI) using the gradient-recalled echo technique with clinical MR scanner, the activated areas nearly correspond with the cortical veins. This suggests that the fMRI signal mainly originates from the cortical veins. In this study, we analyzed the flow velocity in the cortical vein quantitatively during brain activation and resting status using 2 dimensional time-of-flight cine MR venography (2D-TOF-cine-MRV) and 2 dimensional phase contrast MRV (2D-PC-MRV) techniques, and demonstrated that the flow velocity increased in the cortical vein corresponding to the activated area during activation status. The increase of flow velocity was calculated to be about 20%. The reason for the increased flow velocity is probably due to the increased regional cerebral blood flow and volume in the activated area. We should be careful to analyze the data of the fMRI because the flow velocity affects the fMRI signal such as the inflow effect and the oblique flow effect. When using the gradient echo method, the effect of the flow velocity is one of the important factors of the fMRI signal. (author)

  12. Early-life exposure to caffeine affects the construction and activity of cortical networks in mice.

    Science.gov (United States)

    Fazeli, Walid; Zappettini, Stefania; Marguet, Stephan Lawrence; Grendel, Jasper; Esclapez, Monique; Bernard, Christophe; Isbrandt, Dirk

    2017-09-01

    The consumption of psychoactive drugs during pregnancy can have deleterious effects on newborns. It remains unclear whether early-life exposure to caffeine, the most widely consumed psychoactive substance, alters brain development. We hypothesized that maternal caffeine ingestion during pregnancy and the early postnatal period in mice affects the construction and activity of cortical networks in offspring. To test this hypothesis, we focused on primary visual cortex (V1) as a model neocortical region. In a study design mimicking the daily consumption of approximately three cups of coffee during pregnancy in humans, caffeine was added to the drinking water of female mice and their offspring were compared to control offspring. Caffeine altered the construction of GABAergic neuronal networks in V1, as reflected by a reduced number of somatostatin-containing GABA neurons at postnatal days 6-7, with the remaining ones showing poorly developed dendritic arbors. These findings were accompanied by increased synaptic activity in vitro and elevated network activity in vivo in V1. Similarly, in vivo hippocampal network activity was altered from the neonatal period until adulthood. Finally, caffeine-exposed offspring showed increased seizure susceptibility in a hyperthermia-induced seizure model. In summary, our results indicate detrimental effects of developmental caffeine exposure on mouse brain development. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Comparable cortical activation with inferior performance in women during a novel cognitive inhibition task.

    Science.gov (United States)

    Halari, R; Kumari, V

    2005-03-07

    Men are hypothesised to perform better than women at tasks requiring cognitive inhibition. The present study applied whole-brain functional magnetic resonance imaging to investigate the neural correlates of cognitive inhibition using a novel task, requiring detection of numbers decreasing in numerical order, in relation to sex. The study involved 19 young healthy subjects (9 men, 10 women). Behavioural sex differences favouring men were found on the inhibition, but not on the automatization (i.e. detection of numbers increasing in numerical order), condition of the task. Significant areas of activation associated with cognitive inhibition included the right inferior prefrontal and bilateral dorsolateral prefrontal cortices, left inferior and superior parietal lobes, and bilateral temporal regions across men and women. No brain region was significantly differently activated in men and women. Our findings demonstrate that (a) cognitive inhibition is dependent on intact processes within frontal and parietal regions, and (b) women show inferior cognitive inhibition despite of comparable activation to men in relevant regions. Equated behavioural performance may elicit sex differences in brain activation.

  14. Ethanol modulates cortical activity: direct evidence with combined TMS and EEG.

    Science.gov (United States)

    Kähkönen, S; Kesäniemi, M; Nikouline, V V; Karhu, J; Ollikainen, M; Holi, M; Ilmoniemi, R J

    2001-08-01

    The motor cortex of 10 healthy subjects was stimulated by transcranial magnetic stimulation (TMS) before and after ethanol challenge (0.8 g/kg resulting in blood concentration of 0.77 +/- 0.14 ml/liter). The electrical brain activity resulting from the brief electromagnetic pulse was recorded with high-resolution electroencephalography (EEG) and located using inversion algorithms. Focal magnetic pulses to the left motor cortex were delivered with a figure-of-eight coil at the random interstimulus interval of 1.5-2.5 s. The stimulation intensity was adjusted to the motor threshold of abductor digiti minimi. Two conditions before and after ethanol ingestion (30 min) were applied: (1) real TMS, with the coil pressed against the scalp; and (2) control condition, with the coil separated from the scalp by a 2-cm-thick piece of plastic. A separate EMG control recording of one subject during TMS was made with two bipolar platinum needle electrodes inserted to the left temporal muscle. In each condition, 120 pulses were delivered. The EEG was recorded from 60 scalp electrodes. A peak in the EEG signals was observed at 43 ms after the TMS pulse in the real-TMS condition but not in the control condition or in the control scalp EMG. Potential maps before and after ethanol ingestion were significantly different from each other (P = 0.01), but no differences were found in the control condition. Ethanol changed the TMS-evoked potentials over right frontal and left parietal areas, the underlying effect appearing to be largest in the right prefrontal area. Our findings suggest that ethanol may have changed the functional connectivity between prefrontal and motor cortices. This new noninvasive method provides direct evidence about the modulation of cortical connectivity after ethanol challenge. Copyright 2001 Academic Press.

  15. Cortical Regions Recruited for Complex Active-Learning Strategies and Action Planning Exhibit Rapid Reactivation during Memory Retrieval

    Science.gov (United States)

    Voss, Joel L.; Galvan, Ashley; Gonsalves, Brian D.

    2011-01-01

    Memory retrieval can involve activity in the same sensory cortical regions involved in perception of the original event, and this neural "reactivation" has been suggested as an important mechanism of memory retrieval. However, it is still unclear if fragments of experience other than sensory information are retained and later reactivated during…

  16. A Matching Activity When Entering Higher Education: Ongoing Guidance for the Students or Efficiency Instrument for the School?

    Science.gov (United States)

    Mittendorff, Kariene; Faber, Marike; Staman, Laura

    2017-01-01

    In order to lower dropout rates and stimulate student success in higher education, the Dutch government implemented a new law demanding that every higher education institute offer a matching activity to applying students. This article evaluates how students and teachers experience this matching activity. Data were collected in a Dutch university…

  17. Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study.

    Directory of Open Access Journals (Sweden)

    Makii Muthalib

    Full Text Available Neuroimaging studies have shown neuromuscular electrical stimulation (NMES-evoked movements activate regions of the cortical sensorimotor network, including the primary sensorimotor cortex (SMC, premotor cortex (PMC, supplementary motor area (SMA, and secondary somatosensory area (S2, as well as regions of the prefrontal cortex (PFC known to be involved in pain processing. The aim of this study, on nine healthy subjects, was to compare the cortical network activation profile and pain ratings during NMES of the right forearm wrist extensor muscles at increasing current intensities up to and slightly over the individual maximal tolerated intensity (MTI, and with reference to voluntary (VOL wrist extension movements. By exploiting the capability of the multi-channel time domain functional near-infrared spectroscopy technique to relate depth information to the photon time-of-flight, the cortical and superficial oxygenated (O2Hb and deoxygenated (HHb hemoglobin concentrations were estimated. The O2Hb and HHb maps obtained using the General Linear Model (NIRS-SPM analysis method, showed that the VOL and NMES-evoked movements significantly increased activation (i.e., increase in O2Hb and corresponding decrease in HHb in the cortical layer of the contralateral sensorimotor network (SMC, PMC/SMA, and S2. However, the level and area of contralateral sensorimotor network (including PFC activation was significantly greater for NMES than VOL. Furthermore, there was greater bilateral sensorimotor network activation with the high NMES current intensities which corresponded with increased pain ratings. In conclusion, our findings suggest that greater bilateral sensorimotor network activation profile with high NMES current intensities could be in part attributable to increased attentional/pain processing and to increased bilateral sensorimotor integration in these cortical regions.

  18. Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study.

    Science.gov (United States)

    Muthalib, Makii; Re, Rebecca; Zucchelli, Lucia; Perrey, Stephane; Contini, Davide; Caffini, Matteo; Spinelli, Lorenzo; Kerr, Graham; Quaresima, Valentina; Ferrari, Marco; Torricelli, Alessandro

    2015-01-01

    Neuroimaging studies have shown neuromuscular electrical stimulation (NMES)-evoked movements activate regions of the cortical sensorimotor network, including the primary sensorimotor cortex (SMC), premotor cortex (PMC), supplementary motor area (SMA), and secondary somatosensory area (S2), as well as regions of the prefrontal cortex (PFC) known to be involved in pain processing. The aim of this study, on nine healthy subjects, was to compare the cortical network activation profile and pain ratings during NMES of the right forearm wrist extensor muscles at increasing current intensities up to and slightly over the individual maximal tolerated intensity (MTI), and with reference to voluntary (VOL) wrist extension movements. By exploiting the capability of the multi-channel time domain functional near-infrared spectroscopy technique to relate depth information to the photon time-of-flight, the cortical and superficial oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin concentrations were estimated. The O2Hb and HHb maps obtained using the General Linear Model (NIRS-SPM) analysis method, showed that the VOL and NMES-evoked movements significantly increased activation (i.e., increase in O2Hb and corresponding decrease in HHb) in the cortical layer of the contralateral sensorimotor network (SMC, PMC/SMA, and S2). However, the level and area of contralateral sensorimotor network (including PFC) activation was significantly greater for NMES than VOL. Furthermore, there was greater bilateral sensorimotor network activation with the high NMES current intensities which corresponded with increased pain ratings. In conclusion, our findings suggest that greater bilateral sensorimotor network activation profile with high NMES current intensities could be in part attributable to increased attentional/pain processing and to increased bilateral sensorimotor integration in these cortical regions.

  19. D2 receptor genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans.

    Science.gov (United States)

    Fazio, Leonardo; Blasi, Giuseppe; Taurisano, Paolo; Papazacharias, Apostolos; Romano, Raffaella; Gelao, Barbara; Ursini, Gianluca; Quarto, Tiziana; Lo Bianco, Luciana; Di Giorgio, Annabella; Mancini, Marina; Popolizio, Teresa; Rubini, Giuseppe; Bertolino, Alessandro

    2011-02-14

    Pre-synaptic D2 receptors regulate striatal dopamine release and DAT activity, key factors for modulation of motor pathways. A functional SNP of DRD2 (rs1076560 G>T) is associated with alternative splicing such that the relative expression of D2S (mainly pre-synaptic) vs. D2L (mainly post-synaptic) receptor isoforms is decreased in subjects with the T allele with a putative increase of striatal dopamine levels. To evaluate how DRD2 genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans, we have investigated the association of rs1076560 with BOLD fMRI activity during a motor task. To further evaluate the relationship of this circuitry with dopamine signaling, we also explored the correlation between genotype based differences in motor brain activity and pre-synaptic striatal DAT binding measured with [(123)I] FP-CIT SPECT. Fifty healthy subjects, genotyped for DRD2 rs1076560 were studied with BOLD-fMRI at 3T while performing a visually paced motor task with their right hand; eleven of these subjects also underwent [(123)I]FP-CIT SPECT. SPM5 random-effects models were used for statistical analyses. Subjects carrying the T allele had greater BOLD responses in left basal ganglia, thalamus, supplementary motor area, and primary motor cortex, whose activity was also negatively correlated with reaction time at the task. Moreover, left striatal DAT binding and activity of left supplementary motor area were negatively correlated. The present results suggest that DRD2 genetic variation was associated with focusing of responses in the whole motor network, in which activity of predictable nodes was correlated with reaction time and with striatal pre-synaptic dopamine signaling. Our results in humans may help shed light on genetic risk for neurobiological mechanisms involved in the pathophysiology of disorders with dysregulation of striatal dopamine like Parkinson's disease. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Cortical activation during power grip task with pneumatic pressure gauge: an fMRI study

    Science.gov (United States)

    Mohamad, M.; Mardan, N. H.; Ismail, S. S.

    2017-05-01

    Aging is associated with a decline in cognitive and motor function. But, the relationships with motor performance are less well understood. In this study, functional magnetic resonance imaging (fMRI) was used to assess cortical activation in older adults. This study employed power grip task that utilised block paradigm consisted of alternate 30s rest and active. A visual cue was used to pace the hand grip movement that clenched a cylindrical rubber bulb connected with pressure pneumatic gauge that measure the pressure (Psi). The objective of this study is determined the brain areas activated during motor task and the correlation between percentage signal change of each motor area (BA 4 and 6) and hand grip pressure. Result showed there was a significant difference in mean percentage signal change in BA 4 and BA 6 in both hemispheres and negative correlation obtained in BA 4 and BA 6. These results indicate that a reduced ability in the motor networks contribute to age-related decline in motor performance.

  1. Cortical activation during power grip task with pneumatic pressure gauge: an fMRI study

    International Nuclear Information System (INIS)

    Mohamad, M; Ismail, S S; Mardan, N H

    2017-01-01

    Aging is associated with a decline in cognitive and motor function. But, the relationships with motor performance are less well understood. In this study, functional magnetic resonance imaging (fMRI) was used to assess cortical activation in older adults. This study employed power grip task that utilised block paradigm consisted of alternate 30s rest and active. A visual cue was used to pace the hand grip movement that clenched a cylindrical rubber bulb connected with pressure pneumatic gauge that measure the pressure (Psi). The objective of this study is determined the brain areas activated during motor task and the correlation between percentage signal change of each motor area (BA 4 and 6) and hand grip pressure. Result showed there was a significant difference in mean percentage signal change in BA 4 and BA 6 in both hemispheres and negative correlation obtained in BA 4 and BA 6. These results indicate that a reduced ability in the motor networks contribute to age-related decline in motor performance. (paper)

  2. Locus Coeruleus α-Adrenergic–Mediated Activation of Cortical Astrocytes In Vivo

    Science.gov (United States)

    He, Wei; Nedergaard, Maiken

    2008-01-01

    The locus coeruleus (LC) provides the sole source of norepinephrine (NE) to the cortex for modulation of cortical synaptic activity in response to salient sensory information. NE has been shown to improve signal-to-noise ratios, sharpen receptive fields and function in learning, memory, and cognitive performance. Although LC-mediated effects on neurons have been addressed, involvement of astrocytes has thus far not been demonstrated in these neuromodulatory functions. Here we show for the 1st time in live mice, that astrocytes exhibit rapid Ca2+ increases in response to electrical stimulation of the LC. Additionally, robust peripheral stimulation known to result in phasic LC activity leads to Ca2+ responses in astrocytes throughout sensory cortex that are independent of sensory-driven glutamate-dependent pathways. Furthermore, the astrocytic Ca2+ transients are competitively modulated by α2-specific agonist/antagonist combinations known to impact LC output, are sensitive to the LC-specific neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, and are inhibited locally by an α-adrenergic antagonist. Future investigations of LC function must therefore consider the possibility that LC neuromodulatory effects are in part derived from activation of astrocytes. PMID:18372288

  3. Locus coeruleus alpha-adrenergic-mediated activation of cortical astrocytes in vivo.

    Science.gov (United States)

    Bekar, Lane K; He, Wei; Nedergaard, Maiken

    2008-12-01

    The locus coeruleus (LC) provides the sole source of norepinephrine (NE) to the cortex for modulation of cortical synaptic activity in response to salient sensory information. NE has been shown to improve signal-to-noise ratios, sharpen receptive fields and function in learning, memory, and cognitive performance. Although LC-mediated effects on neurons have been addressed, involvement of astrocytes has thus far not been demonstrated in these neuromodulatory functions. Here we show for the 1st time in live mice, that astrocytes exhibit rapid Ca(2+) increases in response to electrical stimulation of the LC. Additionally, robust peripheral stimulation known to result in phasic LC activity leads to Ca(2+) responses in astrocytes throughout sensory cortex that are independent of sensory-driven glutamate-dependent pathways. Furthermore, the astrocytic Ca(2+) transients are competitively modulated by alpha(2)-specific agonist/antagonist combinations known to impact LC output, are sensitive to the LC-specific neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, and are inhibited locally by an alpha-adrenergic antagonist. Future investigations of LC function must therefore consider the possibility that LC neuromodulatory effects are in part derived from activation of astrocytes.

  4. Glimepiride attenuates Aβ production via suppressing BACE1 activity in cortical neurons.

    Science.gov (United States)

    Liu, Feiyang; Wang, Yijin; Yan, Ming; Zhang, Luyong; Pang, Tao; Liao, Hong

    2013-12-17

    Numerous lines of evidence suggest a strong link between diabetes mellitus and Alzheimer's disease (AD). Impaired insulin signaling and insulin resistance occur not only in diabetes but also in the brain of AD. Recent evidence has indicated that peroxisome proliferator-activated receptor γ (PPARγ) agonists thiazolidinediones (TZDs) can decrease β-amyloid peptide (Aβ) deposition, which is the core component of senile plaques in AD, but the underlying mechanisms still remain unclear. In this study, we investigated whether glimepiride with PPARγ-stimulating activity, an oral anti-diabetic drug, has similar effects on Aβ production in primary cortical neurons. We demonstrated that glimepiride decreased extracellular Aβ40 and Aβ42 levels. The effect of glimepiride on reduction of Aβ40 generation was mediated by downregulation of β-site APP-cleaving enzyme 1 (BACE1) mRNA and protein expression, and by suppression of BACE1 activity. In addition, we found that high glucose condition enhanced Aβ40 production and glimepiride significantly decreased high glucose-induced Aβ40 production. Finally, a specific PPARγ antagonist GW9662 reversed glimepiride inhibitory effect on Aβ40 generation, suggesting a PPARγ-dependent mechanism may be involved. Our data indicated that glimepiride may serve as a promising drug for the treatment of AD associated with diabetes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Population decoding of motor cortical activity using a generalized linear model with hidden states.

    Science.gov (United States)

    Lawhern, Vernon; Wu, Wei; Hatsopoulos, Nicholas; Paninski, Liam

    2010-06-15

    Generalized linear models (GLMs) have been developed for modeling and decoding population neuronal spiking activity in the motor cortex. These models provide reasonable characterizations between neural activity and motor behavior. However, they lack a description of movement-related terms which are not observed directly in these experiments, such as muscular activation, the subject's level of attention, and other internal or external states. Here we propose to include a multi-dimensional hidden state to address these states in a GLM framework where the spike count at each time is described as a function of the hand state (position, velocity, and acceleration), truncated spike history, and the hidden state. The model can be identified by an Expectation-Maximization algorithm. We tested this new method in two datasets where spikes were simultaneously recorded using a multi-electrode array in the primary motor cortex of two monkeys. It was found that this method significantly improves the model-fitting over the classical GLM, for hidden dimensions varying from 1 to 4. This method also provides more accurate decoding of hand state (reducing the mean square error by up to 29% in some cases), while retaining real-time computational efficiency. These improvements on representation and decoding over the classical GLM model suggest that this new approach could contribute as a useful tool to motor cortical decoding and prosthetic applications. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  6. Population Decoding of Motor Cortical Activity using a Generalized Linear Model with Hidden States

    Science.gov (United States)

    Lawhern, Vernon; Wu, Wei; Hatsopoulos, Nicholas G.; Paninski, Liam

    2010-01-01

    Generalized linear models (GLMs) have been developed for modeling and decoding population neuronal spiking activity in the motor cortex. These models provide reasonable characterizations between neural activity and motor behavior. However, they lack a description of movement-related terms which are not observed directly in these experiments, such as muscular activation, the subject's level of attention, and other internal or external states. Here we propose to include a multi-dimensional hidden state to address these states in a GLM framework where the spike count at each time is described as a function of the hand state (position, velocity, and acceleration), truncated spike history, and the hidden state. The model can be identified by an Expectation-Maximization algorithm. We tested this new method in two datasets where spikes were simultaneously recorded using a multi-electrode array in the primary motor cortex of two monkeys. It was found that this method significantly improves the model-fitting over the classical GLM, for hidden dimensions varying from 1 to 4. This method also provides more accurate decoding of hand state (lowering the Mean Square Error by up to 29% in some cases), while retaining real-time computational efficiency. These improvements on representation and decoding over the classical GLM model suggest that this new approach could contribute as a useful tool to motor cortical decoding and prosthetic applications. PMID:20359500

  7. Mapping cortical mesoscopic networks of single spiking cortical or sub-cortical neurons.

    Science.gov (United States)

    Xiao, Dongsheng; Vanni, Matthieu P; Mitelut, Catalin C; Chan, Allen W; LeDue, Jeffrey M; Xie, Yicheng; Chen, Andrew Cn; Swindale, Nicholas V; Murphy, Timothy H

    2017-02-04

    Understanding the basis of brain function requires knowledge of cortical operations over wide-spatial scales, but also within the context of single neurons. In vivo, wide-field GCaMP imaging and sub-cortical/cortical cellular electrophysiology were used in mice to investigate relationships between spontaneous single neuron spiking and mesoscopic cortical activity. We make use of a rich set of cortical activity motifs that are present in spontaneous activity in anesthetized and awake animals. A mesoscale spike-triggered averaging procedure allowed the identification of motifs that are preferentially linked to individual spiking neurons by employing genetically targeted indicators of neuronal activity. Thalamic neurons predicted and reported specific cycles of wide-scale cortical inhibition/excitation. In contrast, spike-triggered maps derived from single cortical neurons yielded spatio-temporal maps expected for regional cortical consensus function. This approach can define network relationships between any point source of neuronal spiking and mesoscale cortical maps.

  8. Locally formed dopamine inhibits Na sup + -K sup + -ATPase activity in rat renal cortical tubule cells

    Energy Technology Data Exchange (ETDEWEB)

    Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J. (Harvard Medical School, Boston, MA (USA) Karolinska Institute, Stockholm (Sweden))

    1988-10-01

    Dopamine, generated locally from L-dopa, inhibits Na{sup +}-K{sup +}-ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na{sup +}-K{sup +}-ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate ({dot Q}o{sub 2}) and {sup 86}Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive {dot Q}o{sub 2} or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive {dot Q}o{sub 2} in a concentration-dependent manner, with half-maximal inhibition (K{sub 0.5}) of 5 {times} 10{sup {minus}7} M and a maximal inhibition of 14.1 {plus minus} 1.5% at 10{sup {minus}4}M. L-Dopa also blunted the nystatin-stimulated {dot Q}o{sub 2} in a concentration-dependent manner, indicating the L-dopa directly inhibits Na{sup +}-K{sup +}-ATPase activity and not sodium entry. Ouabain-sensitive {sup 86}Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} and {sup 86}Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na{sup +}-K{sup +}-ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner.

  9. Differential patterns of cortical activation as a function of fluid reasoning complexity.

    Science.gov (United States)

    Perfetti, Bernardo; Saggino, Aristide; Ferretti, Antonio; Caulo, Massimo; Romani, Gian Luca; Onofrj, Marco

    2009-02-01

    Fluid intelligence (gf) refers to abstract reasoning and problem solving abilities. It is considered a human higher cognitive factor central to general intelligence (g). The regions of the cortex supporting gf have been revealed by recent bioimaging studies and valuable hypothesis on the neural correlates of individual differences have been proposed. However, little is known about the interaction between individual variability in gf and variation in cortical activity following task complexity increase. To further investigate this, two samples of participants (high-IQ, N = 8; low-IQ, N = 10) with significant differences in gf underwent two reasoning (moderate and complex) tasks and a control task adapted from the Raven progressive matrices. Functional magnetic resonance was used and the recorded signal analyzed between and within the groups. The present study revealed two opposite patterns of neural activity variation which were probably a reflection of the overall differences in cognitive resource modulation: when complexity increased, high-IQ subjects showed a signal enhancement in some frontal and parietal regions, whereas low-IQ subjects revealed a decreased activity in the same areas. Moreover, a direct comparison between the groups' activation patterns revealed a greater neural activity in the low-IQ sample when conducting moderate task, with a strong involvement of medial and lateral frontal regions thus suggesting that the recruitment of executive functioning might be different between the groups. This study provides evidence for neural differences in facing reasoning complexity among subjects with different gf level that are mediated by specific patterns of activation of the underlying fronto-parietal network.

  10. CNTF-ACM promotes mitochondrial respiration and oxidative stress in cortical neurons through upregulating L-type calcium channel activity.

    Science.gov (United States)

    Sun, Meiqun; Liu, Hongli; Xu, Huanbai; Wang, Hongtao; Wang, Xiaojing

    2016-09-01

    A specialized culture medium termed ciliary neurotrophic factor-treated astrocyte-conditioned medium (CNTF-ACM) allows investigators to assess the peripheral effects of CNTF-induced activated astrocytes upon cultured neurons. CNTF-ACM has been shown to upregulate neuronal L-type calcium channel current activity, which has been previously linked to changes in mitochondrial respiration and oxidative stress. Therefore, the aim of this study was to evaluate CNTF-ACM's effects upon mitochondrial respiration and oxidative stress in rat cortical neurons. Cortical neurons, CNTF-ACM, and untreated control astrocyte-conditioned medium (UC-ACM) were prepared from neonatal Sprague-Dawley rat cortical tissue. Neurons were cultured in either CNTF-ACM or UC-ACM for a 48-h period. Changes in the following parameters before and after treatment with the L-type calcium channel blocker isradipine were assessed: (i) intracellular calcium levels, (ii) mitochondrial membrane potential (ΔΨm), (iii) oxygen consumption rate (OCR) and adenosine triphosphate (ATP) formation, (iv) intracellular nitric oxide (NO) levels, (v) mitochondrial reactive oxygen species (ROS) production, and (vi) susceptibility to the mitochondrial complex I toxin rotenone. CNTF-ACM neurons displayed the following significant changes relative to UC-ACM neurons: (i) increased intracellular calcium levels (p ACM (p ACM promotes mitochondrial respiration and oxidative stress in cortical neurons through elevating L-type calcium channel activity.

  11. Cortical activation to object shape and speed of motion during the first year.

    Science.gov (United States)

    Wilcox, Teresa; Hawkins, Laura B; Hirshkowitz, Amy; Boas, David A

    2014-10-01

    A great deal is known about the functional organization of cortical networks that mediate visual object processing in the adult. The current research is part of a growing effort to identify the functional maturation of these pathways in the developing brain. The current research used near-infrared spectroscopy to investigate functional activation of the infant cortex during the processing of featural information (shape) and spatiotemporal information (speed of motion) during the first year of life. Our investigation focused on two areas that were implicated in previous studies: anterior temporal cortex and posterior parietal cortex. Neuroimaging data were collected with 207 infants across three age groups: 3-6 months (Experiment 1), 7-8 months (Experiment 2), and 10-12 months (Experiments 3 and 4). The neuroimaging data revealed age-related changes in patterns of activation to shape and speed information, mostly involving posterior parietal areas, some of which were predicted and others that were not. We suggest that these changes reflect age-related differences in the perceptual and/or cognitive processes engaged during the task. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Neural speech recognition: continuous phoneme decoding using spatiotemporal representations of human cortical activity

    Science.gov (United States)

    Moses, David A.; Mesgarani, Nima; Leonard, Matthew K.; Chang, Edward F.

    2016-10-01

    Objective. The superior temporal gyrus (STG) and neighboring brain regions play a key role in human language processing. Previous studies have attempted to reconstruct speech information from brain activity in the STG, but few of them incorporate the probabilistic framework and engineering methodology used in modern speech recognition systems. In this work, we describe the initial efforts toward the design of a neural speech recognition (NSR) system that performs continuous phoneme recognition on English stimuli with arbitrary vocabulary sizes using the high gamma band power of local field potentials in the STG and neighboring cortical areas obtained via electrocorticography. Approach. The system implements a Viterbi decoder that incorporates phoneme likelihood estimates from a linear discriminant analysis model and transition probabilities from an n-gram phonemic language model. Grid searches were used in an attempt to determine optimal parameterizations of the feature vectors and Viterbi decoder. Main results. The performance of the system was significantly improved by using spatiotemporal representations of the neural activity (as opposed to purely spatial representations) and by including language modeling and Viterbi decoding in the NSR system. Significance. These results emphasize the importance of modeling the temporal dynamics of neural responses when analyzing their variations with respect to varying stimuli and demonstrate that speech recognition techniques can be successfully leveraged when decoding speech from neural signals. Guided by the results detailed in this work, further development of the NSR system could have applications in the fields of automatic speech recognition and neural prosthetics.

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

    Science.gov (United States)

    Moses, David A.; Leonard, Matthew K.; Chang, Edward F.

    2018-06-01

    Objective. 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. Approach. 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. Main results. 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. Significance. Further development and testing of the package with different speech paradigms could influence the design of future speech neuroprosthetic applications.

  14. Central as well as peripheral attentional bottlenecks in dual-task performance activate lateral prefrontal cortices

    Directory of Open Access Journals (Sweden)

    Andre J Szameitat

    2016-03-01

    Full Text Available Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage as well as peripheral limitations (i.e., bottleneck at response initiation both demand executive functions located in the lateral prefrontal cortex. For this, we re-analysed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP during fMRI. In one study (N=17, the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group. In the other study (N=16, the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group. Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect. Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices. Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns suggest that the executive functions resolving

  15. Circulating biologically active oxidized phospholipids show on-going and increased oxidative stress in older male mice

    Directory of Open Access Journals (Sweden)

    Jinbo Liu

    2013-01-01

    Significance: Oxidatively modified phospholipids are increased in the circulation during common, mild oxidant stresses of aging, or in male compared to female animals. Turnover of these biologically active phospholipids by rapid transport into liver and kidney is unchanged, so circulating levels reflect continuously increased production.

  16. 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)

  17. Spiking in auditory cortex following thalamic stimulation is dominated by cortical network activity

    Science.gov (United States)

    Krause, Bryan M.; Raz, Aeyal; Uhlrich, Daniel J.; Smith, Philip H.; Banks, Matthew I.

    2014-01-01

    The state of the sensory cortical network can have a profound impact on neural responses and perception. In rodent auditory cortex, sensory responses are reported to occur in the context of network events, similar to brief UP states, that produce “packets” of spikes and are associated with synchronized synaptic input (Bathellier et al., 2012; Hromadka et al., 2013; Luczak et al., 2013). However, traditional models based on data from visual and somatosensory cortex predict that ascending sensory thalamocortical (TC) pathways sequentially activate cells in layers 4 (L4), L2/3, and L5. The relationship between these two spatio-temporal activity patterns is unclear. Here, we used calcium imaging and electrophysiological recordings in murine auditory TC brain slices to investigate the laminar response pattern to stimulation of TC afferents. We show that although monosynaptically driven spiking in response to TC afferents occurs, the vast majority of spikes fired following TC stimulation occurs during brief UP states and outside the context of the L4>L2/3>L5 activation sequence. Specifically, monosynaptic subthreshold TC responses with similar latencies were observed throughout layers 2–6, presumably via synapses onto dendritic processes located in L3 and L4. However, monosynaptic spiking was rare, and occurred primarily in L4 and L5 non-pyramidal cells. By contrast, during brief, TC-induced UP states, spiking was dense and occurred primarily in pyramidal cells. These network events always involved infragranular layers, whereas involvement of supragranular layers was variable. During UP states, spike latencies were comparable between infragranular and supragranular cells. These data are consistent with a model in which activation of auditory cortex, especially supragranular layers, depends on internally generated network events that represent a non-linear amplification process, are initiated by infragranular cells and tightly regulated by feed-forward inhibitory

  18. Activation of Wnt Signaling in Cortical Neurons Enhances Glucose Utilization through Glycolysis.

    Science.gov (United States)

    Cisternas, Pedro; Salazar, Paulina; Silva-Álvarez, Carmen; Barros, L Felipe; Inestrosa, Nibaldo C

    2016-12-09

    The Wnt signaling pathway is critical for a number of functions in the central nervous system, including regulation of the synaptic cleft structure and neuroprotection against injury. Deregulation of Wnt signaling has been associated with several brain pathologies, including Alzheimer's disease. In recent years, it has been suggested that the Wnt pathway might act as a central integrator of metabolic signals from peripheral organs to the brain, which would represent a new role for Wnt signaling in cell metabolism. Energy metabolism is critical for normal neuronal function, which mainly depends on glucose utilization. Brain energy metabolism is important in almost all neurological disorders, to which a decrease in the capacity of the brain to utilize glucose has been linked. However, little is known about the relationship between Wnt signaling and neuronal glucose metabolism in the cellular context. In the present study, we found that acute treatment with the Wnt3a ligand induced a large increase in glucose uptake, without changes in the expression or localization of glucose transporter type 3. In addition, we observed that Wnt3a treatment increased the activation of the metabolic sensor Akt. Moreover, we observed an increase in the activity of hexokinase and in the glycolytic rate, and both processes were dependent on activation of the Akt pathway. Furthermore, we did not observe changes in the activity of glucose-6-phosphate dehydrogenase or in the pentose phosphate pathway. The effect of Wnt3a was independent of both the transcription of Wnt target genes and synaptic effects of Wnt3a. Together, our results suggest that Wnt signaling stimulates glucose utilization in cortical neurons through glycolysis to satisfy the high energy demand of these cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Electronic bypass of spinal lesions: activation of lower motor neurons directly driven by cortical neural signals.

    Science.gov (United States)

    Li, Yan; Alam, Monzurul; Guo, Shanshan; Ting, K H; He, Jufang

    2014-07-03

    Lower motor neurons in the spinal cord lose supraspinal inputs after complete spinal cord injury, leading to a loss of volitional control below the injury site. Extensive locomotor training with spinal cord stimulation can restore locomotion function after spinal cord injury in humans and animals. However, this locomotion is non-voluntary, meaning that subjects cannot control stimulation via their natural "intent". A recent study demonstrated an advanced system that triggers a stimulator using forelimb stepping electromyographic patterns to restore quadrupedal walking in rats with spinal cord transection. However, this indirect source of "intent" may mean that other non-stepping forelimb activities may false-trigger the spinal stimulator and thus produce unwanted hindlimb movements. We hypothesized that there are distinguishable neural activities in the primary motor cortex during treadmill walking, even after low-thoracic spinal transection in adult guinea pigs. We developed an electronic spinal bridge, called "Motolink", which detects these neural patterns and triggers a "spinal" stimulator for hindlimb movement. This hardware can be head-mounted or carried in a backpack. Neural data were processed in real-time and transmitted to a computer for analysis by an embedded processor. Off-line neural spike analysis was conducted to calculate and preset the spike threshold for "Motolink" hardware. We identified correlated activities of primary motor cortex neurons during treadmill walking of guinea pigs with spinal cord transection. These neural activities were used to predict the kinematic states of the animals. The appropriate selection of spike threshold value enabled the "Motolink" system to detect the neural "intent" of walking, which triggered electrical stimulation of the spinal cord and induced stepping-like hindlimb movements. We present a direct cortical "intent"-driven electronic spinal bridge to restore hindlimb locomotion after complete spinal cord injury.

  20. Altered cortical activation during action observation in amyotrophic lateral sclerosis patients: a parametric functional MRI study

    International Nuclear Information System (INIS)

    Li, Haiqing; Li, Yuxin; Yin, Bo; Tang, Weijun; Yu, Xiangrong; Geng, Daoying; Chen, Yan; Huang, Weiyuan; Zhang, Biyun

    2015-01-01

    To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation. Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors. Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls. The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function. (orig.)

  1. Altered cortical activation during action observation in amyotrophic lateral sclerosis patients: a parametric functional MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haiqing; Li, Yuxin; Yin, Bo; Tang, Weijun; Yu, Xiangrong; Geng, Daoying [Huashan Hospital, Department of Radiology, Fudan University, Shanghai (China); Chen, Yan [Fudan University, Department of Neurology, Huashan Hospital, Shanghai (China); Huang, Weiyuan [People' s Hospital of Hainan Province, Department of Radiology, Haikou, Hainan Province (China); Zhang, Biyun [Nanjing University of Traditional Chinese Medicine, Department of radiotherapy, Affiliated Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China)

    2015-09-15

    To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation. Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors. Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls. The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function. (orig.)

  2. TMS-induced cortical potentiation during wakefulness locally increases slow wave activity during sleep.

    Directory of Open Access Journals (Sweden)

    Reto Huber

    2007-03-01

    Full Text Available Sleep slow wave activity (SWA is thought to reflect sleep need, increasing in proportion to the length of prior wakefulness and decreasing during sleep. However, the process responsible for SWA regulation is not known. We showed recently that SWA increases locally after a learning task involving a circumscribed brain region, suggesting that SWA may reflect plastic changes triggered by learning.To test this hypothesis directly, we used transcranial magnetic stimulation (TMS in conjunction with high-density EEG in humans. We show that 5-Hz TMS applied to motor cortex induces a localized potentiation of TMS-evoked cortical EEG responses. We then show that, in the sleep episode following 5-Hz TMS, SWA increases markedly (+39.1+/-17.4%, p<0.01, n = 10. Electrode coregistration with magnetic resonance images localized the increase in SWA to the same premotor site as the maximum TMS-induced potentiation during wakefulness. Moreover, the magnitude of potentiation during wakefulness predicts the local increase in SWA during sleep.These results provide direct evidence for a link between plastic changes and the local regulation of sleep need.

  3. Spatiotemporal alterations of cortical network activity by selective loss of NOS-expressing interneurons .

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    Dan eShlosberg

    2012-02-01

    Full Text Available Deciphering the role of GABAergic neurons in large neuronal networks such as the neocortex forms a particularly complex task as they comprise a highly diverse population. The neuronal isoform of the enzyme nitric oxide synthase (nNOS is expressed in the neocortex by specific subsets of GABAergic neurons. These neurons can be identified in live brain slices by the nitric oxide (NO fluorescent indicator DAF-2DA. However, this indicator was found to be highly toxic to the stained neurons. We used this feature to induce acute phototoxic damage to NO-producing neurons in cortical slices, and measured subsequent alterations in parameters of cellular and network activity.Neocortical slices were briefly incubated in DAF-2DA and then illuminated through the 4X objective. Histochemistry for NADPH diaphorase, a marker for nNOS activity, revealed elimination of staining in the illuminated areas following treatment. Whole cell recordings from several neuronal types before, during and after illumination confirmed the selective damage to non fast-spiking interneurons. Treated slices displayed mild disinhibition. The reversal potential of compound synaptic events on pyramidal neurons became more positive, and their decay time constant was elongated, substantiating the removal of an inhibitory conductance. The horizontal decay of local field potentials (LFPs was significantly reduced at distances of 300-400 m from the stimulation, but not when inhibition was non-selectively weakened with the GABAA blocker picrotoxin. Finally, whereas the depression of LFPs along short trains of 40 Hz stimuli was linearly reduced with distance or initial amplitude in control slices, this ordered relationship was disrupted in DAF-treated slices. These results reveal that NO-producing interneurons in the neocortex convey lateral inhibition to neighboring columns, and shape the spatiotemporal dynamics of the network's activity.

  4. Spatiotemporal alterations of cortical network activity by selective loss of NOS-expressing interneurons.

    Science.gov (United States)

    Shlosberg, Dan; Buskila, Yossi; Abu-Ghanem, Yasmin; Amitai, Yael

    2012-01-01

    Deciphering the role of GABAergic neurons in large neuronal networks such as the neocortex forms a particularly complex task as they comprise a highly diverse population. The neuronal isoform of the enzyme nitric oxide synthase (nNOS) is expressed in the neocortex by specific subsets of GABAergic neurons. These neurons can be identified in live brain slices by the nitric oxide (NO) fluorescent indicator diaminofluorescein-2 diacetate (DAF-2DA). However, this indicator was found to be highly toxic to the stained neurons. We used this feature to induce acute phototoxic damage to NO-producing neurons in cortical slices, and measured subsequent alterations in parameters of cellular and network activity. Neocortical slices were briefly incubated in DAF-2DA and then illuminated through the 4× objective. Histochemistry for NADPH-diaphorase (NADPH-d), a marker for nNOS activity, revealed elimination of staining in the illuminated areas following treatment. Whole cell recordings from several neuronal types before, during, and after illumination confirmed the selective damage to non-fast-spiking (FS) interneurons. Treated slices displayed mild disinhibition. The reversal potential of compound synaptic events on pyramidal neurons became more positive, and their decay time constant was elongated, substantiating the removal of an inhibitory conductance. The horizontal decay of local field potentials (LFPs) was significantly reduced at distances of 300-400 μm from the stimulation, but not when inhibition was non-selectively weakened with the GABA(A) blocker picrotoxin. Finally, whereas the depression of LFPs along short trains of 40 Hz stimuli was linearly reduced with distance or initial amplitude in control slices, this ordered relationship was disrupted in DAF-treated slices. These results reveal that NO-producing interneurons in the neocortex convey lateral inhibition to neighboring columns, and shape the spatiotemporal dynamics of the network's activity.

  5. Reprogramming movements: Extraction of motor intentions from cortical ensemble activity when movement goals change

    Directory of Open Access Journals (Sweden)

    Peter James Ifft

    2012-07-01

    Full Text Available The ability to inhibit unwanted movements and change motor plans is essential for behaviors of advanced organisms. The neural mechanisms by which the primate motor system rejects undesired actions have received much attention during the last decade, but it is not well understood how this neural function could be utilized to improve the efficiency of brain-machine interfaces (BMIs. Here we employed linear discriminant analysis (LDA and a Wiener filter to extract motor plan transitions from the activity of ensembles of sensorimotor cortex neurons. Two rhesus monkeys, chronically implanted with multielectrode arrays in primary motor (M1 and primary sensory (S1 cortices, were overtrained to produce reaching movements with a joystick towards visual targets upon their presentation. Then, the behavioral task was modified to include a distracting target that flashed for 50, 150 or 250 ms (25% of trials each followed by the true target that appeared at a different screen location. In the remaining 25% of trials, the initial target stayed on the screen and was the target to be approached. M1 and S1 neuronal activity represented both the true and distracting targets, even for the shortest duration of the distracting event. This dual representation persisted both when the monkey initiated movements towards the distracting target and then made corrections and when they moved directly towards the second, true target. The Wiener filter effectively decoded the location of the true target, whereas the LDA classifier extracted the location of both targets from ensembles of 50-250 neurons. Based on these results, we suggest developing real-time BMIs that inhibit unwanted movements represented by brain activity while enacting the desired motor outcome concomitantly.

  6. Functional characterization of GABAA receptor-mediated modulation of cortical neuron network activity in microelectrode array recordings

    DEFF Research Database (Denmark)

    Bader, Benjamin M; Steder, Anne; Klein, Anders Bue

    2017-01-01

    The numerous γ-aminobutyric acid type A receptor (GABAAR) subtypes are differentially expressed and mediate distinct functions at neuronal level. In this study we have investigated GABAAR-mediated modulation of the spontaneous activity patterns of primary neuronal networks from murine frontal...... of the information extractable from the MEA recordings offers interesting insights into the contributions of various GABAAR subtypes/subgroups to cortical network activity and the putative functional interplay between these receptors in these neurons....... cortex by characterizing the effects induced by a wide selection of pharmacological tools at a plethora of activity parameters in microelectrode array (MEA) recordings. The basic characteristics of the primary cortical neurons used in the recordings were studied in some detail, and the expression levels...

  7. Multiple source genes of HAmo SINE actively expanded and ongoing retroposition in cyprinid genomes relying on its partner LINE

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    Gan Xiaoni

    2010-04-01

    Full Text Available Abstract Background We recently characterized HAmo SINE and its partner LINE in silver carp and bighead carp based on hybridization capture of repetitive elements from digested genomic DNA in solution using a bead-probe 1. To reveal the distribution and evolutionary history of SINEs and LINEs in cyprinid genomes, we performed a multi-species search for HAmo SINE and its partner LINE using the bead-probe capture and internal-primer-SINE polymerase chain reaction (PCR techniques. Results Sixty-seven full-size and 125 internal-SINE sequences (as well as 34 full-size and 9 internal sequences previously reported in bighead carp and silver carp from 17 species of the family Cyprinidae were aligned as well as 14 new isolated HAmoL2 sequences. Four subfamilies (type I, II, III and IV, which were divided based on diagnostic nucleotides in the tRNA-unrelated region, expanded preferentially within a certain lineage or within the whole family of Cyprinidae as multiple active source genes. The copy numbers of HAmo SINEs were estimated to vary from 104 to 106 in cyprinid genomes by quantitative RT-PCR. Over one hundred type IV members were identified and characterized in the primitive cyprinid Danio rerio genome but only tens of sequences were found to be similar with type I, II and III since the type IV was the oldest subfamily and its members dispersed in almost all investigated cyprinid fishes. For determining the taxonomic distribution of HAmo SINE, inter-primer SINE PCR was conducted in other non-cyprinid fishes, the results shows that HAmo SINE- related sequences may disperse in other families of order Cypriniforms but absent in other orders of bony fishes: Siluriformes, Polypteriformes, Lepidosteiformes, Acipenseriformes and Osteoglossiforms. Conclusions Depending on HAmo LINE2, multiple source genes (subfamilies of HAmo SINE actively expanded and underwent retroposition in a certain lineage or within the whole family of Cyprinidae. From this

  8. Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test.

    Science.gov (United States)

    Okonogi, Toya; Nakayama, Ryota; Sasaki, Takuya; Ikegaya, Yuji

    2018-01-01

    Elevated plus maze (EPM) tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs), electrocardiograms (ECGs), electromyograms (EMGs), and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

  9. Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test

    Directory of Open Access Journals (Sweden)

    Toya Okonogi

    2018-04-01

    Full Text Available Elevated plus maze (EPM tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs, electrocardiograms (ECGs, electromyograms (EMGs, and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

  10. Nifedipine-activated Ca(2+) permeability in newborn rat cortical collecting duct cells in primary culture.

    Science.gov (United States)

    Valencia, L; Bidet, M; Martial, S; Sanchez, E; Melendez, E; Tauc, M; Poujeol, C; Martin, D; Namorado, M D; Reyes, J L; Poujeol, P

    2001-05-01

    To characterize Ca(2+) transport in newborn rat cortical collecting duct (CCD) cells, we used nifedipine, which in adult rat distal tubules inhibits the intracellular Ca(2+) concentration ([Ca(2+)](i)) increase in response to hormonal activation. We found that the dihydropyridine (DHP) nifedipine (20 microM) produced an increase in [Ca(2+)](i) from 87.6 +/- 3.3 nM to 389.9 +/- 29.0 nM in 65% of the cells. Similar effects of other DHP (BAY K 8644, isradipine) were also observed. Conversely, DHPs did not induce any increase in [Ca(2+)](i) in cells obtained from proximal convoluted tubule. In CCD cells, neither verapamil nor diltiazem induced any rise in [Ca(2+)](i). Experiments in the presence of EGTA showed that external Ca(2+) was required for the nifedipine effect, while lanthanum (20 microM), gadolinium (100 microM), and diltiazem (20 microM) inhibited the effect. Experiments done in the presence of valinomycin resulted in the same nifedipine effect, showing that K(+) channels were not involved in the nifedipine-induced [Ca(2+)](i) rise. H(2)O(2) also triggered [Ca(2+)](i) rise. However, nifedipine-induced [Ca(2+)](i) increase was not affected by protamine. In conclusion, the present results indicate that 1) primary cultures of cells from terminal nephron of newborn rats are a useful tool for investigating Ca(2+) transport mechanisms during growth, and 2) newborn rat CCD cells in primary culture exhibit a new apical nifedipine-activated Ca(2+) channel of capacitive type (either transient receptor potential or leak channel).

  11. Changes in cortical activity associated with adaptive behavior during repeated balance perturbation of unpredictable timing

    Directory of Open Access Journals (Sweden)

    Andreas eMierau

    2015-10-01

    Full Text Available The compensation for a sudden balance perturbation, unpracticed and unpredictable in timing and magnitude is accompanied by pronounced postural instability that is suggested to be causal to falls. However, subsequent presentations of an identical perturbation are characterized by a marked decrease of the amplitude of postural reactions; a phenomenon called adaptation or habituation. This study aimed to identify cortical characteristics associated with adaptive behavior during repetitive balance perturbations based on single-trial analyses of the P1 and N1 perturbation-evoked potentials. Thirty-seven young men were exposed to ten transient balance perturbations while balancing on the dominant leg. 32-channel EEG, surface EMG of the ankle plantar flexor muscles and postural sway (i.e. Euclidean distance of the supporting platform were recorded simultaneously. The P1 and N1 potentials were localized and the amplitude/latency was analyzed trial by trial. The best match sources for P1 and N1 potentials were located in the parietal (Brodmann area 5 and midline fronto-central cortex (Brodmann area 6, respectively. The amplitude and latency of the P1 potential remained unchanged over trials. In contrast, a significant adaptation of the N1 amplitude was observed. Similar adaptation effects were found with regard to postural sway and m. peroneus longus EMG activity of the non-dominant (free leg; an indicator reduced muscular co-contraction and/or less temporary bipedal stance to regain stability. Significant but weak correlations were found between N1 amplitude and postural sway as well as EMG activity. These results highlight the important role of the midline fronto-central cortex for adaptive behavior associated with balance control.

  12. Protein phosphatase 2ACα gene knock-out results in cortical atrophy through activating hippo cascade in neuronal progenitor cells.

    Science.gov (United States)

    Liu, Bo; Sun, Li-Hua; Huang, Yan-Fei; Guo, Li-Jun; Luo, Li-Shu

    2018-02-01

    Protein phosphatase 2ACα (PP2ACα), a vital member of the protein phosphatase family, has been studied primarily as a regulator for the development, growth and protein synthesis of a lot of cell types. Dysfunction of PP2ACα protein results in neurodegenerative disease; however, this finding has not been directly confirmed in the mouse model with PP2ACα gene knock-out. Therefore, in this study presented here, we generated the PP2ACα gene knock-out mouse model by the Cre-loxP targeting gene system, with the purpose to directly observe the regulatory role of PP2ACα gene in the development of mouse's cerebral cortex. We observe that knocking-out PP2ACα gene in the central nervous system (CNS) results in cortical neuronal shrinkage, synaptic plasticity impairments, and learning/memory deficits. Further study reveals that PP2ACα gene knock-out initiates Hippo cascade in cortical neuroprogenitor cells (NPCs), which blocks YAP translocation into the nuclei of NPCs. Notably, p73, directly targeted by Hippo cascade, can bind to the promoter of glutaminase2 (GLS2) that plays a dominant role in the enzymatic regulation of glutamate/glutamine cycle. Finally, we find that PP2ACα gene knock-out inhibits the glutamine synthesis through up-regulating the activity of phosphorylated-p73 in cortical NPCs. Taken together, it concludes that PP2ACα critically supports cortical neuronal growth and cognitive function via regulating the signaling transduction of Hippo-p73 cascade. And PP2ACα indirectly modulates the glutamine synthesis of cortical NPCs through targeting p73 that plays a direct transcriptional regulatory role in the gene expression of GLS2. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Ongoing experiments: diagnostics requirements

    International Nuclear Information System (INIS)

    Dickerman, C.E.

    1976-01-01

    The paper reviews the fuel motion diagnostics needs for ongoing LMFBR safety experiments over approximately the next five years, with the discussion centered on TREAT. Brief comments on the direction in which clad motion diagnostics requirements are expected to develop are also presented

  14. Age-Related Differences in Cortical Activity during a Visuo-Spatial Working Memory Task with Facial Stimuli

    OpenAIRE

    Belham, Fl?via Schechtman; Satler, Corina; Garcia, Ana; Tomaz, Carlos; Gasbarri, Antonella; Rego, Artur; Tavares, Maria Clotilde H.

    2013-01-01

    Emotion, importantly displayed by facial expressions, is one of the most significant memory modulators. The interaction between memory and the different emotional valences change across lifespan, while young adults (YA) are expected to better recall negative events (Negativity Bias Hypothesis), older adults (OA) tend to focus on positive stimuli (Positivity Effect Hypothesis). This research work aims at verifying whether cortical electrical activity of these two age groups would also be diffe...

  15. Dissociating Cortical Activity during Processing of Native and Non-Native Audiovisual Speech from Early to Late Infancy

    Directory of Open Access Journals (Sweden)

    Eswen Fava

    2014-08-01

    Full Text Available Initially, infants are capable of discriminating phonetic contrasts across the world’s languages. Starting between seven and ten months of age, they gradually lose this ability through a process of perceptual narrowing. Although traditionally investigated with isolated speech sounds, such narrowing occurs in a variety of perceptual domains (e.g., faces, visual speech. Thus far, tracking the developmental trajectory of this tuning process has been focused primarily on auditory speech alone, and generally using isolated sounds. But infants learn from speech produced by people talking to them, meaning they learn from a complex audiovisual signal. Here, we use near-infrared spectroscopy to measure blood concentration changes in the bilateral temporal cortices of infants in three different age groups: 3-to-6 months, 7-to-10 months, and 11-to-14-months. Critically, all three groups of infants were tested with continuous audiovisual speech in both their native and another, unfamiliar language. We found that at each age range, infants showed different patterns of cortical activity in response to the native and non-native stimuli. Infants in the youngest group showed bilateral cortical activity that was greater overall in response to non-native relative to native speech; the oldest group showed left lateralized activity in response to native relative to non-native speech. These results highlight perceptual tuning as a dynamic process that happens across modalities and at different levels of stimulus complexity.

  16. Glutamate and GABA contributions to medial prefrontal cortical activity to emotion: implications for mood disorders.

    Science.gov (United States)

    Stan, Ana D; Schirda, Claudiu V; Bertocci, Michele A; Bebko, Genna M; Kronhaus, Dina M; Aslam, Haris A; LaBarbara, Eduard J; Tanase, Costin; Lockovich, Jeanette C; Pollock, Myrna H; Stiffler, Richelle S; Phillips, Mary L

    2014-09-30

    The dorsomedial prefrontal cortex (MdPFC) and anterior cingulate cortices (ACC) play a critical role in implicit emotion regulation; however the understanding of the specific neurotransmitters that mediate such role is lacking. In this study, we examined relationships between MdPFC concentrations of two neurotransmitters, glutamate and γ-amino butyric acid (GABA), and BOLD activity in ACC during performance of an implicit facial emotion-processing task. Twenty healthy volunteers, aged 20-35 years, were scanned while performing an implicit facial emotion-processing task, whereby presented facial expressions changed from neutral to one of the four emotions: happy, anger, fear, or sad. Glutamate concentrations were measured before and after the emotion-processing task in right MdPFC using magnetic resonance spectroscopy (MRS). GABA concentrations were measured in bilateral MdPFC after the emotion-processing task. Multiple regression models were run to determine the relative contribution of glutamate and GABA concentration, age, and gender to BOLD signal in ACC to each of the four emotions. Multiple regression analyses revealed a significant negative correlation between MdPFC GABA concentration and BOLD signal in subgenual ACC (psad versus shape contrast. For the anger versus shape contrast, there was a significant negative correlation between age and BOLD signal in pregenual ACC (p<0.05, corrected) and a positive correlation between MdPFC glutamate concentration (pre-task) and BOLD signal in pregenual ACC (p<0.05, corrected). Our findings are the first to provide insight into relationships between MdPFC neurotransmitter concentrations and ACC BOLD signal, and could further understanding of molecular mechanisms underlying emotion processing in healthy and mood-disordered individuals. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. An fMRI study on cortical responses during active self-touch and passive touch from others

    Directory of Open Access Journals (Sweden)

    Rochelle eAckerley

    2012-08-01

    Full Text Available Active, self-touch and the passive touch from an external source engage comparable afferent mechanoreceptors on the touched skin site. However, touch directed to glabrous skin compared to hairy skin will activate different types of afferent mechanoreceptors. Despite perceptual similarities between touch to different body sites, it is likely that the touch information is processed differently. In the present study, we used functional magnetic resonance imaging (fMRI to elucidate the cortical differences in the neural signal of touch representations during active, self-touch and passive touch from another, to both glabrous (palm and hairy (arm skin, where a soft brush was used as the stimulus. There were two active touch conditions, where the participant used the brush in their right hand to stroke either their left palm or arm. There were two similar passive, touch conditions where the experimenter used an identical brush to stroke the same palm and arm areas on the participant. Touch on the left palm elicited a large, significant, positive blood-oxygenation level dependence (BOLD signal in right sensorimotor areas. Less extensive activity was found for touch to the arm. Separate somatotopical palm and arm representations were found in Brodmann area 3 of the right primary somatosensory cortex (SI and in both these areas, active stroking gave significantly higher signals than passive stroking. Active, self-touch elicited a positive BOLD signal in a network of sensorimotor cortical areas in the left hemisphere, compared to the resting baseline. In contrast, during passive touch, a significant negative BOLD signal was found in the left SI. Thus, each of the four conditions had a unique cortical signature despite similarities in afferent signalling or evoked perception. It is hypothesized that attentional mechanisms play a role in the modulation of the touch signal in the right SI, accounting for the differences found between active and passive touch.

  18. Chronic 14-day exposure to insecticides or methylmercury modulates neuronal activity in primary rat cortical cultures

    NARCIS (Netherlands)

    Dingemans, Milou; Schütte, Marijke G; Wiersma, Daphne M M; de Groot, Aart; van Kleef, Gina; Wijnolts, Fiona; Westerink, Remco

    2016-01-01

    There is an increasing demand for in vitro test systems to detect neurotoxicity for use in chemical risk assessment. In this study, we evaluated the applicability of rat primary cortical cultures grown on multi-well micro-electrode arrays (mwMEAs) to detect effects of chronic 14-day exposure to

  19. Cortical control of object-specific grasp relies on adjustments of both activity and effective connectivity

    DEFF Research Database (Denmark)

    Tia, Banty; Takemi, Mitsuaki; Kosugi, Akito

    2017-01-01

    The cortical mechanisms of grasping have been extensively studied in macaques and humans. Here, we investigated whether common marmosets could rely on similar mechanisms despite striking differences in manual dexterity. Two common marmosets were trained to grasp-and-pull three objects eliciting d...

  20. Differential Involvement of Amygdala and Cortical NMDA Receptors Activation upon Encoding in Odor Fear Memory

    Science.gov (United States)

    Hegoburu, Chloé; Parrot, Sandrine; Ferreira, Guilaume; Mouly, Anne-Marie

    2014-01-01

    Although the basolateral amygdala (BLA) plays a crucial role for the acquisition of fear memories, sensory cortices are involved in their long-term storage in rats. However, the time course of their respective involvement has received little investigation. Here we assessed the role of the glutamatergic N-methyl-D-aspartate (NMDA) receptors in the…

  1. Longitudinal development of frontoparietal activity during feedback learning: Contributions of age, performance, working memory and cortical thickness.

    Science.gov (United States)

    Peters, Sabine; Van Duijvenvoorde, Anna C K; Koolschijn, P Cédric M P; Crone, Eveline A

    2016-06-01

    Feedback learning is a crucial skill for cognitive flexibility that continues to develop into adolescence, and is linked to neural activity within a frontoparietal network. Although it is well conceptualized that activity in the frontoparietal network changes during development, there is surprisingly little consensus about the direction of change. Using a longitudinal design (N=208, 8-27 years, two measurements in two years), we investigated developmental trajectories in frontoparietal activity during feedback learning. Our first aim was to test for linear and nonlinear developmental trajectories in dorsolateral prefrontal cortex (DLPFC), superior parietal cortex (SPC), supplementary motor area (SMA) and anterior cingulate cortex (ACC). Second, we tested which factors (task performance, working memory, cortical thickness) explained additional variance in time-related changes in activity besides age. Developmental patterns for activity in DLPFC and SPC were best characterized by a quadratic age function leveling off/peaking in late adolescence. There was a linear increase in SMA and a linear decrease with age in ACC activity. In addition to age, task performance explained variance in DLPFC and SPC activity, whereas cortical thickness explained variance in SMA activity. Together, these findings provide a novel perspective of linear and nonlinear developmental changes in the frontoparietal network during feedback learning. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Longitudinal development of frontoparietal activity during feedback learning: Contributions of age, performance, working memory and cortical thickness

    Directory of Open Access Journals (Sweden)

    Sabine Peters

    2016-06-01

    Full Text Available Feedback learning is a crucial skill for cognitive flexibility that continues to develop into adolescence, and is linked to neural activity within a frontoparietal network. Although it is well conceptualized that activity in the frontoparietal network changes during development, there is surprisingly little consensus about the direction of change. Using a longitudinal design (N = 208, 8–27 years, two measurements in two years, we investigated developmental trajectories in frontoparietal activity during feedback learning. Our first aim was to test for linear and nonlinear developmental trajectories in dorsolateral prefrontal cortex (DLPFC, superior parietal cortex (SPC, supplementary motor area (SMA and anterior cingulate cortex (ACC. Second, we tested which factors (task performance, working memory, cortical thickness explained additional variance in time-related changes in activity besides age. Developmental patterns for activity in DLPFC and SPC were best characterized by a quadratic age function leveling off/peaking in late adolescence. There was a linear increase in SMA and a linear decrease with age in ACC activity. In addition to age, task performance explained variance in DLPFC and SPC activity, whereas cortical thickness explained variance in SMA activity. Together, these findings provide a novel perspective of linear and nonlinear developmental changes in the frontoparietal network during feedback learning.

  3. Effects of Habitual Physical Activity and Fitness on Tibial Cortical Bone Mass, Structure and Mass Distribution in Pre-pubertal Boys and Girls: The Look Study.

    Science.gov (United States)

    Duckham, Rachel L; Rantalainen, Timo; Ducher, Gaele; Hill, Briony; Telford, Richard D; Telford, Rohan M; Daly, Robin M

    2016-07-01

    Targeted weight-bearing activities during the pre-pubertal years can improve cortical bone mass, structure and distribution, but less is known about the influence of habitual physical activity (PA) and fitness. This study examined the effects of contrasting habitual PA and fitness levels on cortical bone density, geometry and mass distribution in pre-pubertal children. Boys (n = 241) and girls (n = 245) aged 7-9 years had a pQCT scan to measure tibial mid-shaft total, cortical and medullary area, cortical thickness, density, polar strength strain index (SSIpolar) and the mass/density distribution through the bone cortex (radial distribution divided into endo-, mid- and pericortical regions) and around the centre of mass (polar distribution). Four contrasting PA and fitness groups (inactive-unfit, inactive-fit, active-unfit, active-fit) were generated based on daily step counts (pedometer, 7-days) and fitness levels (20-m shuttle test and vertical jump) for boys and girls separately. Active-fit boys had 7.3-7.7 % greater cortical area and thickness compared to inactive-unfit boys (P girls, but active-fit girls had 6.1 % (P girls, which was likely due to their 6.7 % (P active-fit girls. Higher levels of habitual PA-fitness were associated with small regional-specific gains in 66 % tibial cortical bone mass in pre-pubertal children, particularly boys.

  4. Cortical activities of single-trial P300 amplitudes modulated by memory load using simultaneous EEG-fMRI

    Science.gov (United States)

    Zhang, Qiushi; Zhao, Xiaojie; Zhu, Chaozhe; Yang, Xueqian; Yao, Li

    2015-03-01

    The functional magnetic resonance imaging (fMRI) researches on working memory have found that activation of cortical areas appeared dependent on memory load, and event-related potentials (ERP) studies have demonstrated that amplitudes of P300 decreased significantly when working memory load increased. However, the cortical activities related with P300 amplitudes under different memory loads remains unclear. Joint fMRI and EEG analysis which fusions the time and spatial information in simultaneous EEG-fMRI recording can reveal the regional activation at each ERP time point. In this paper, we first used wavelet transform to obtain the single-trial amplitudes of P300 caused by a digital N-back task in the simultaneous EEG-fMRI recording as the ERP feature sequences. Then the feature sequences in 1-back condition and 3-back condition were introduced into general linear model (GLM) separately as parametric modulations to compare the cortical activation under different memory loads. The results showed that the average amplitudes of P300 in 3-back significantly decreased than that in 1-back, and the activities induced by ERP feature sequences in 3-back also significantly decreased than that in the 1-back, including the insular, anterior cingulate cortex, right inferior frontal gyrus, and medial frontal gyrus, which were relevant to the storage, monitoring, and manipulation of information in working memory task. Moreover, the difference in the activation caused by ERP feature showed a positive correlation with the difference in behavioral performance. These findings demonstrated the locations of P300 amplitudes differences modulated by the memory load and its relationship with the behavioral performance.

  5. Decreased cortical activation in response to a motion stimulus in anisometropic amblyopic eyes using functional magnetic resonance imaging.

    Science.gov (United States)

    Bonhomme, Gabrielle R; Liu, Grant T; Miki, Atsushi; Francis, Ellie; Dobre, M-C; Modestino, Edward J; Aleman, David O; Haselgrove, John C

    2006-12-01

    Motion perception abnormalities and extrastriate abnormalities have been suggested in amblyopia. Functional MRI (fMRI) and motion stimuli were used to study whether interocular differences in activation are detectable in motion-sensitive cortical areas in patients with anisometropic amblyopia. We performed fMRI at 1.5 T 4 control subjects (20/20 OU), 1 with monocular suppression (20/25), and 2 with anisometropic amblyopia (20/60, 20/800). Monocular suppression was thought to be form fruste of amblyopia. The experimental stimulus consisted of expanding and contracting concentric rings, whereas the control condition consisted of stationary concentric rings. Activation was determined by contrasting the 2 conditions for each eye. Significant fMRI activation and comparable right and left eye activation was found in V3a and V5 in all control subjects (Average z-values in L vs R contrast 0.42, 0.43) and in the subject with monocular suppression (z = 0.19). The anisometropes exhibited decreased extrastriate activation in their amblyopic eyes compared with the fellow eyes (zs = 2.12, 2.76). Our data suggest motion-sensitive cortical structures may be less active when anisometropic amblyopic eyes are stimulated with moving rings. These results support the hypothesis that extrastriate cortex is affected in anisometropic amblyopia. Although suggestive of a magnocellular defect, the exact mechanism is unclear.

  6. Age-related differences in cortical activity during a visuo-spatial working memory task with facial stimuli.

    Directory of Open Access Journals (Sweden)

    Flávia Schechtman Belham

    Full Text Available Emotion, importantly displayed by facial expressions, is one of the most significant memory modulators. The interaction between memory and the different emotional valences change across lifespan, while young adults (YA are expected to better recall negative events (Negativity Bias Hypothesis, older adults (OA tend to focus on positive stimuli (Positivity Effect Hypothesis. This research work aims at verifying whether cortical electrical activity of these two age groups would also be differently influenced by emotional valences in a visuo-spatial working memory task. 27 YA (13 males and 25 OA (14 males, all healthy volunteers, underwent electroencephalographic recordings (21 scalp electrodes montage, while performing the Spatial Delayed Recognition Span Task using a touch screen with different stimuli categories: neutral, positive and negative faces and geometric pictures. YA obtained higher scores than OA, and showed higher activation of theta and alpha bands in the frontal and midline regions, besides a more evident right-hemispheric asymmetry on alpha band when compared to OA. For both age groups, performance in the task was worse for positive faces than to negative and to neutral faces. Facial stimuli induced a better performance and higher alpha activation on the pre-frontal region for YA, and on the midline, occipital and left temporal regions for OA when compared to geometric figures. The superior performance of YA was expected due to the natural cognitive deficits connected to ageing, as was a better performance with facial stimuli due to the evolutionary importance of faces. These results were related to cortical activity on areas of importance for action-planning, decision making and sustained attention. Taken together, they are in accordance with the Negativity Bias but do not support the Positivity Effect. The methodology used was able to identify age-related differences in cortical activity during emotional mnemonic processing and

  7. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

    International Nuclear Information System (INIS)

    Gu, Da-min; Lu, Pei-Hua; Zhang, Ke; Wang, Xiang; Sun, Min; Chen, Guo-Qian; Wang, Qiong

    2015-01-01

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R

  8. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Da-min [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Lu, Pei-Hua, E-mail: lphty1_1@163.com [Department of Medical Oncology, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Zhang, Ke; Wang, Xiang [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Sun, Min [Department of General Surgery, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Chen, Guo-Qian [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Wang, Qiong, E-mail: WangQiongprof1@126.com [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China)

    2015-02-13

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R.

  9. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    International Nuclear Information System (INIS)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T.

    2005-01-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  10. Log wavelet leaders cumulant based multifractal analysis of EVI fMRI time series: evidence of scaling in ongoing and evoked brain activity

    Energy Technology Data Exchange (ETDEWEB)

    Ciuciu, P.; Rabrait, C. [CEA, Neuro Spin, Gif Sur Yvette (France); Abry, P.; Wendt, H. [Ecole Normale Super Lyon, Phys Lab, CNRS, UMR 5672, Lyon (France)

    2008-07-01

    Classical within-subject analysis in functional magnetic resonance imaging (fMRI) relies on a detection step to localize which parts of the brain are activated by a given stimulus type. This is usually achieved using model-based approaches. Here, we propose an alternative exploratory analysis. The originality of this contribution is twofold. First, we propose a synthetic, consistent, and comparative overview of the various stochastic processes and estimation procedures used to model and analyze scale invariance. Notably, it is explained how multifractal models are more versatile to adjust the scaling properties of fMRI data but require more elaborated analysis procedures. Second, we bring evidence of the existence of actual scaling in fMRI time series that are clearly disentangled from putative superimposed non-stationarities. By nature, scaling analysis requires the use of long enough signals with high frequency sampling rate. To this end, we make use of a localized 3-D echo volume imaging (EVI) technique, which has recently emerged in fMRI because it allows very fast acquisitions of successive brain volumes. High temporal resolution EVI fMRI data have been acquired both in resting state and during a slow event-related visual paradigm. A voxel-based systematic multifractal analysis has been performed over both kinds of data. Combining multifractal attribute estimates together with paired statistical tests, we observe significant scaling parameter changes between ongoing and evoked brain activity, which clearly validate an increase in long memory and suggest a global multi-fractality decrease effect under activation. (authors)

  11. Cortical Activation during a Cognitive Challenge in Patients with Chronic Temporal Lobe Epilepsy—A Dynamic SPECT Study

    Directory of Open Access Journals (Sweden)

    P. J. Kirkpatrick

    1993-01-01

    Full Text Available In a pilot group of six patients suffering from chronic temporal lobe epilepsy, single photon emission computerized tomography (SPECT has been used to image the changes in relative cerebral blood flow between rest (static scan and conditions of cognitive activation (activated scan. The cognitive challenge used during activation comprised a test of word memory, and the performance was expressed as a word memory score (WMS for each individual. An activation index (AI was calculated from the mean normalized density counts in specific regions of interest (ROIs, and values obtained were analysed for correlation with the WMS. The mean AI was increased significantly in the right lateral temporal cortex, the right and left inferior frontal regions, the left temporal pole, and the right medial temporal cortex. A positive correlation with the WMS was found in the medial temporal cortices, and this relationship was significant for the right medial temporal ROI.

  12. Anosognosia in mild cognitive impairment: Relationship to activation of cortical midline structures involved in self-appraisal

    Science.gov (United States)

    Ries, Michele L.; Jabbar, Britta M.; Schmitz, Taylor W.; Trivedi, Mehul A.; Gleason, Carey E.; Carlsson, Cynthia M.; Rowley, Howard A.; Asthana, Sanjay; Johnson, Sterling C.

    2009-01-01

    Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer’s disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants’ activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI participants and 16 age-matched controls, examining brain regions showing conjoint or differential BOLD response during self-appraisal. Second, we used regression to investigate the relationship between awareness of deficit in MCI and BOLD activity during self-appraisal, controlling for extent of memory impairment. Between-group comparisons indicated that MCI participants show subtly attenuated CMS activity during self-appraisal. Regression analysis revealed a highly-significant relationship between BOLD response during self-appraisal and self-awareness of deficit in MCI. This finding highlights the level of anosognosia in MCI as an important predictor of response to self-appraisal in cortical midline structures, brain regions vulnerable to changes in early AD. PMID:17445294

  13. Glucose and lactate are equally effective in energizing activity-dependent synaptic vesicle turnover in purified cortical neurons.

    Science.gov (United States)

    Morgenthaler, F D; Kraftsik, R; Catsicas, S; Magistretti, P J; Chatton, J-Y

    2006-08-11

    This study examines the role of glucose and lactate as energy substrates to sustain synaptic vesicle cycling. Synaptic vesicle turnover was assessed in a quantitative manner by fluorescence microscopy in primary cultures of mouse cortical neurons. An electrode-equipped perfusion chamber was used to stimulate cells both by electrical field and potassium depolarization during image acquisition. An image analysis procedure was elaborated to select in an unbiased manner synaptic boutons loaded with the fluorescent dye N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide (FM1-43). Whereas a minority of the sites fully released their dye content following electrical stimulation, others needed subsequent K(+) depolarization to achieve full release. This functional heterogeneity was not significantly altered by the nature of metabolic substrates. Repetitive stimulation sequences of FM1-43 uptake and release were then performed in the absence of any metabolic substrate and showed that the number of active sites dramatically decreased after the first cycle of loading/unloading. The presence of 1 mM glucose or lactate was sufficient to sustain synaptic vesicle cycling under these conditions. Moreover, both substrates were equivalent for recovery of function after a phase of decreased metabolic substrate availability. Thus, lactate appears to be equivalent to glucose for sustaining synaptic vesicle turnover in cultured cortical neurons during activity.

  14. Oscillatory neuronal activity reflects lexical-semantic feature integration within and across sensory modalities in distributed cortical networks.

    Science.gov (United States)

    van Ackeren, Markus J; Schneider, Till R; Müsch, Kathrin; Rueschemeyer, Shirley-Ann

    2014-10-22

    Research from the previous decade suggests that word meaning is partially stored in distributed modality-specific cortical networks. However, little is known about the mechanisms by which semantic content from multiple modalities is integrated into a coherent multisensory representation. Therefore we aimed to characterize differences between integration of lexical-semantic information from a single modality compared with two sensory modalities. We used magnetoencephalography in humans to investigate changes in oscillatory neuronal activity while participants verified two features for a given target word (e.g., "bus"). Feature pairs consisted of either two features from the same modality (visual: "red," "big") or different modalities (auditory and visual: "red," "loud"). The results suggest that integrating modality-specific features of the target word is associated with enhanced high-frequency power (80-120 Hz), while integrating features from different modalities is associated with a sustained increase in low-frequency power (2-8 Hz). Source reconstruction revealed a peak in the anterior temporal lobe for low-frequency and high-frequency effects. These results suggest that integrating lexical-semantic knowledge at different cortical scales is reflected in frequency-specific oscillatory neuronal activity in unisensory and multisensory association networks. Copyright © 2014 the authors 0270-6474/14/3314318-06$15.00/0.

  15. Perceived Occupational Stress is associated with Decreased Cortical Activity of the Prefrontal Cortex: A Multichannel Near-infrared Spectroscopy Study.

    Science.gov (United States)

    Chou, Po-Han; Lin, Wei-Hao; Hung, Chao-An; Chang, Chiung-Chih; Li, Wan-Rung; Lan, Tsuo-Hung; Huang, Min-Wei

    2016-12-13

    Despite an increasing number of reports on the associations between chronic occupational stress and structural and functional changes of the brain, the underlying neural correlates of perceived occupational stress is still not clear. Perceived stress reflects the extents to which situations are appraised as stressful at a given point in one's life. Using near-infrared spectroscopy, we investigated the associations between perceived occupational stress and cortical activity over the bilateral frontotemporal regions during a verbal fluency test. Sixty-eight participants (17 men, 51 women), 20-62 years of age were recruited. Perceived occupational stress was measured using the Chinese version of Job Content Questionnaire, and the Chinese version of the Copenhagen Burnout Inventory. We found statistically significant negative associations between occupational burnout and brain cortical activity over the fronto-polar and dorsolateral prefrontal cortex during the VFT (r = -0.343 to -0.464). In conclusion, our research demonstrated a possible neural basis of perceived occupational stress that are distributed across the prefrontal cortex.

  16. Phylogenetic investigation of a statewide HIV-1 epidemic reveals ongoing and active transmission networks among men who have sex with men

    Science.gov (United States)

    Chan, Philip A.; Hogan, Joseph W.; Huang, Austin; DeLong, Allison; Salemi, Marco; Mayer, Kenneth H.; Kantor, Rami

    2015-01-01

    Background Molecular epidemiologic evaluation of HIV-1 transmission networks can elucidate behavioral components of transmission that can be targets for intervention. Methods We combined phylogenetic and statistical approaches using pol sequences from patients diagnosed 2004-2011 at a large HIV center in Rhode Island, following 75% of the state’s HIV population. Phylogenetic trees were constructed using maximum likelihood and putative transmission clusters were evaluated using latent class analyses (LCA) to determine association of cluster size with underlying demographic/behavioral characteristics. A logistic growth model was used to assess intra-cluster dynamics over time and predict “active” clusters that were more likely to harbor undiagnosed infections. Results Of 1,166 HIV-1 subtype B sequences, 31% were distributed among 114 statistically-supported, monophyletic clusters (range: 2-15 sequences/cluster). Sequences from men who have sex with men (MSM) formed 52% of clusters. LCA demonstrated that sequences from recently diagnosed (2008-2011) MSM with primary HIV infection (PHI) and other sexually transmitted infections (STIs) were more likely to form larger clusters (Odds Ratio 1.62-11.25, ppornographic stores. Four large clusters with 38 sequences (100% male, 89% MSM) had a high-probability of harboring undiagnosed infections and included younger MSM with PHI and STIs. Conclusions In this first large-scale molecular epidemiologic investigation of HIV-1 transmission in New England, sexual networks among recently diagnosed MSM with PHI and concomitant STIs contributed to ongoing transmission. Characterization of transmission dynamics revealed actively growing clusters which may be targets for intervention. PMID:26258569

  17. Multiple Past Concussions Are Associated with Ongoing Post-Concussive Symptoms but Not Cognitive Impairment in Active-Duty Army Soldiers.

    Science.gov (United States)

    Dretsch, Michael N; Silverberg, Noah D; Iverson, Grant L

    2015-09-01

    The extent to which multiple past concussions are associated with lingering symptoms or mental health problems in military service members is not well understood. The purpose of this study was to examine the association between lifetime concussion history, cognitive functioning, general health, and psychological health in a large sample of fit-for-duty U.S. Army soldiers preparing for deployment. Data on 458 active-duty soldiers were collected and analyzed. A computerized cognitive screening battery (CNS-Vital Signs(®)) was used to assess complex attention (CA), reaction time (RT), processing speed (PS), cognitive flexibility (CF), and memory. Health questionnaires included the Neurobehavioral Symptom Inventory (NSI), PTSD Checklist-Military Version (PCL-M), Zung Depression and Anxiety Scales (ZDS; ZAS), Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and the Alcohol Use and Dependency Identification Test (AUDIT). Soldiers with a history of multiple concussions (i.e., three or more concussions) had significantly greater post-concussive symptom scores compared with those with zero (d=1.83, large effect), one (d=0.64, medium effect), and two (d=0.64, medium effect) prior concussions. Although the group with three or more concussions also reported more traumatic stress symptoms, the results revealed that traumatic stress was a mediator between concussions and post-concussive symptom severity. There were no significant differences on neurocognitive testing between the number of concussions. These results add to the accumulating evidence suggesting that most individuals recover from one or two prior concussions, but there is a greater risk for ongoing symptoms if one exceeds this number of injuries.

  18. Methods for parameter identification in oscillatory networks and application to cortical and thalamic 600 Hz activity.

    Science.gov (United States)

    Leistritz, L; Suesse, T; Haueisen, J; Hilgenfeld, B; Witte, H

    2006-01-01

    Directed information transfer in the human brain occurs presumably by oscillations. As of yet, most approaches for the analysis of these oscillations are based on time-frequency or coherence analysis. The present work concerns the modeling of cortical 600 Hz oscillations, localized within the Brodmann Areas 3b and 1 after stimulation of the nervus medianus, by means of coupled differential equations. This approach leads to the so-called parameter identification problem, where based on a given data set, a set of unknown parameters of a system of ordinary differential equations is determined by special optimization procedures. Some suitable algorithms for this task are presented in this paper. Finally an oscillatory network model is optimally fitted to the data taken from ten volunteers.

  19. Exposure to high glutamate concentration activates aerobic glycolysis but inhibits ATP-linked respiration in cultured cortical astrocytes.

    Science.gov (United States)

    Shen, Yao; Tian, Yueyang; Shi, Xiaojie; Yang, Jianbo; Ouyang, Li; Gao, Jieqiong; Lu, Jianxin

    2014-08-01

    Astrocytes play a key role in removing the synaptically released glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. However, high concentration of glutamate leads to toxicity in astrocytes, and the underlying mechanisms are unclear. The purpose of this study was to investigate whether energy metabolism disorder, especially impairment of mitochondrial respiration, is involved in the glutamate-induced gliotoxicity. Exposure to 10-mM glutamate for 48 h stimulated glycolysis and respiration in astrocytes. However, the increased oxygen consumption was used for proton leak and non-mitochondrial respiration, but not for oxidative phosphorylation and ATP generation. When the exposure time extended to 72 h, glycolysis was still activated for ATP generation, but the mitochondrial ATP-linked respiration of astrocytes was reduced. The glutamate-induced astrocyte damage can be mimicked by the non-metabolized substrate d-aspartate but reversed by the non-selective glutamate transporter inhibitor TBOA. In addition, the glutamate toxicity can be partially reversed by vitamin E. These findings demonstrate that changes of bioenergetic profile occur in cultured cortical astrocytes exposed to high concentration of glutamate and highlight the role of mitochondria respiration in glutamate-induced gliotoxicity in cortical astrocytes. Copyright © 2014 John Wiley & Sons, Ltd.

  20. In vitro assessment of recombinant, mutant immunoglobulin G anti-D devoid of hemolytic activity for treatment of ongoing hemolytic disease of the fetus and newborn

    DEFF Research Database (Denmark)

    Nielsen, Leif K; Green, Trine H; Sandlie, Inger

    2008-01-01

    A specific treatment for ongoing hemolytic disease of the fetus and newborn (HDFN) due to anti-D would be very attractive. One approach could be administration to the mother of nonhemolytic anti-D, which by crossing the placenta can block the binding of hemolytic maternal anti-D.......A specific treatment for ongoing hemolytic disease of the fetus and newborn (HDFN) due to anti-D would be very attractive. One approach could be administration to the mother of nonhemolytic anti-D, which by crossing the placenta can block the binding of hemolytic maternal anti-D....

  1. Dendritic slow dynamics enables localized cortical activity to switch between mobile and immobile modes with noisy background input.

    Directory of Open Access Journals (Sweden)

    Hiroki Kurashige

    Full Text Available Mounting lines of evidence suggest the significant computational ability of a single neuron empowered by active dendritic dynamics. This motivates us to study what functionality can be acquired by a network of such neurons. The present paper studies how such rich single-neuron dendritic dynamics affects the network dynamics, a question which has scarcely been specifically studied to date. We simulate neurons with active dendrites networked locally like cortical pyramidal neurons, and find that naturally arising localized activity--called a bump--can be in two distinct modes, mobile or immobile. The mode can be switched back and forth by transient input to the cortical network. Interestingly, this functionality arises only if each neuron is equipped with the observed slow dendritic dynamics and with in vivo-like noisy background input. If the bump activity is considered to indicate a point of attention in the sensory areas or to indicate a representation of memory in the storage areas of the cortex, this would imply that the flexible mode switching would be of great potential use for the brain as an information processing device. We derive these conclusions using a natural extension of the conventional field model, which is defined by combining two distinct fields, one representing the somatic population and the other representing the dendritic population. With this tool, we analyze the spatial distribution of the degree of after-spike adaptation and explain how we can understand the presence of the two distinct modes and switching between the modes. We also discuss the possible functional impact of this mode-switching ability.

  2. Preferred chewing side-dependent two-point discrimination and cortical activation pattern of tactile tongue sensation.

    Science.gov (United States)

    Minato, Akiko; Ono, Takashi; Miyamoto, Jun J; Honda, Ei-ichi; Kurabayashi, Tohru; Moriyama, Keiji

    2009-10-12

    Although tactile feedback from the tongue should contribute to habitual chewing, it is unclear how the sensation of the tongue and its projection to the central nervous system differ with regard to the preferred chewing side (PCS). The purpose of this study was to investigate (1) whether the sensory threshold of the tongue differed according to the side and (2) whether the pattern of hemispheric cortical activation by tactile tongue stimulation differed, with special attention to the PCS. Twelve healthy adults participated in the study. The PCS was determined with a mandibular kinesiograph. In the behavioral study, the mean thresholds for two-point discrimination (TPD) in the anterior, canine and posterior regions on both sides of the tongue, and those between PCS and non-PCS in each region were statistically compared. In the functional magnetic resonance imaging study, tactile stimulation was delivered to either side of the tongue with acrylic balls via a mandibular splint. The runs were measured with a T2*-weighted gradient echo-type echo planar imaging sequence in a 1.5T scanner. Activated voxel numbers in the bilateral primary somatosensory cortex (S1) were statistically compared. The threshold of TPD increased in the order of the anterior, canine and posterior regions. Moreover, this threshold was significantly smaller on the PCS than on the non-PCS in both the canine and posterior regions. Moreover, the number of activated voxels in S1 contralateral to the PCS was significantly greater than that in S1 contralateral to the non-PCS. The present study shows that the PCS is associated with asymmetric tactile sensation and cortical activation of the tongue. The sensory acuity of the tongue on the PCS may play an important role in functional coupling between the jaw and tongue to maximize the efficiency of chewing.

  3. Improving students' understanding by using on-going education research to refine active learning activities in a first-year electronics course

    Science.gov (United States)

    Peter Mazzolini, Alexander; Arthur Daniel, Scott

    2016-05-01

    Interactive Lecture Demonstrations (ILDs) have been used across introductory university physics as a successful active learning (AL) strategy to improve students' conceptual understanding. We have developed ILDs for more complex topics in our first-year electronics course. In 2006 we began developing ILDs to improve students' conceptual understanding of Operational Amplifiers (OAs) and negative feedback in amplification circuits. The ILDs were used after traditional lecture instruction to help students consolidate their understanding. We developed a diagnostic test, to be administered to students both before and after the ILDs, as a measure of how effective the ILDs were in improving students' understanding.

  4. Improving students' understanding by using on-going education research to refine active learning activities in a first-year electronics course

    International Nuclear Information System (INIS)

    Mazzolini, Alexander Peter; Daniel, Scott Arthur

    2015-01-01

    Interactive Lecture Demonstrations (ILDs) have been used across introductory university physics as a successful active learning (AL) strategy to improve students’ conceptual understanding. We have developed ILDs for more complex topics in our first-year electronics course. In 2006 we began developing ILDs to improve students’ conceptual understanding of Operational Amplifiers (OAs) and negative feedback in amplification circuits. The ILDs were used after traditional lecture instruction to help students consolidate their understanding. We developed a diagnostic test, to be administered to students both before and after the ILDs, as a measure of how effective the ILDs were in improving students’ understanding.

  5. High gamma power in ECoG reflects cortical electrical stimulation effects on unit activity in layers V/VI

    Science.gov (United States)

    Yazdan-Shahmorad, Azadeh; Kipke, Daryl R.; Lehmkuhle, Mark J.

    2013-12-01

    Objective. Cortical electrical stimulation (CES) has been used extensively in experimental neuroscience to modulate neuronal or behavioral activity, which has led this technique to be considered in neurorehabilitation. Because the cortex and the surrounding anatomy have irregular geometries as well as inhomogeneous and anisotropic electrical properties, the mechanism by which CES has therapeutic effects is poorly understood. Therapeutic effects of CES can be improved by optimizing the stimulation parameters based on the effects of various stimulation parameters on target brain regions. Approach. In this study we have compared the effects of CES pulse polarity, frequency, and amplitude on unit activity recorded from rat primary motor cortex with the effects on the corresponding local field potentials (LFP), and electrocorticograms (ECoG). CES was applied at the surface of the cortex and the unit activity and LFPs were recorded using a penetrating electrode array, which was implanted below the stimulation site. ECoGs were recorded from the vicinity of the stimulation site. Main results. Time-frequency analysis of LFPs following CES showed correlation of gamma frequencies with unit activity response in all layers. More importantly, high gamma power of ECoG signals only correlated with the unit activity in lower layers (V-VI) following CES. Time-frequency correlations, which were found between LFPs, ECoGs and unit activity, were frequency- and amplitude-dependent. Significance. The signature of the neural activity observed in LFP and ECoG signals provides a better understanding of the effects of stimulation on network activity, representative of large numbers of neurons responding to stimulation. These results demonstrate that the neurorehabilitation and neuroprosthetic applications of CES targeting layered cortex can be further improved by using field potential recordings as surrogates to unit activity aimed at optimizing stimulation efficacy. Likewise, the signatures

  6. On-going activities in the European JASMIN project for the development and validation of ASTEC-Na SFR safety simulation code - 15072

    International Nuclear Information System (INIS)

    Girault, N.; Cloarec, L.; Herranz, L.; Bandini, G.; Perez-Martin, S.; Ammirabile, L.

    2015-01-01

    results as well as to other code predictions when simulating an unprotected loss of flow transient. The present paper summarizes the overall on-going activities addressing thermal-hydraulics, fuel behaviour, source term and neutronics. (authors)

  7. Self-sustained firing activities of the cortical network with plastic rules in weak AC electrical fields

    International Nuclear Information System (INIS)

    Qin Ying-Mei; Wang Jiang; Men Cong; Zhao Jia; Wei Xi-Le; Deng Bin

    2012-01-01

    Both external and endogenous electrical fields widely exist in the environment of cortical neurons. The effects of a weak alternating current (AC) field on a neural network model with synaptic plasticity are studied. It is found that self-sustained rhythmic firing patterns, which are closely correlated with the cognitive functions, are significantly modified due to the self-organizing of the network in the weak AC field. The activities of the neural networks are affected by the synaptic connection strength, the external stimuli, and so on. In the presence of learning rules, the synaptic connections can be modulated by the external stimuli, which will further enhance the sensitivity of the network to the external signal. The properties of the external AC stimuli can serve as control parameters in modulating the evolution of the neural network. (interdisciplinary physics and related areas of science and technology)

  8. GPR surveying of transport infrastructures and buildings; underground utility and void sensing - ongoing activities in Working Group 2 of COST Action TU1208

    Science.gov (United States)

    Pajewski, Lara; Plati, Christina; Derobert, Xavier

    2015-04-01

    This work aims at presenting the ongoing research activities carried out in Working Group 2 'GPR surveying of pavements, bridges, tunnels and buildings; underground utility and void sensing' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of Ground Penetrating Radar (GPR) techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Four Working Groups (WGs) carry out the research activities. WG1 focuses on the development of innovative GPR equipment dedicated for civil engineering applications. WG2 deals with the development of guidelines and protocols for the surveying, through the use of a GPR system, of transport infrastructure and buildings, as well as for the sensing of utilities and voids. WG3 deals with the development of electromagnetic forward and inverse scattering methods, for the characterization of GPR scenarios, as well as with data- processing algorithms for the elaboration of the data collected during GPR surveys. WG4 is concerned with the use of GPR in fields different from the civil engineering, as well as with the integration of GPR with other non-destructive testing techniques. Each WG includes several Projects. WG2 includes five Projects. Project 2.1 focuses on outlining 'Innovative inspection procedures for effective GPR surveying of critical transport infrastructures (pavements, bridges and tunnels).' Project 2.2 is concerned with the development of 'Innovative inspection procedures for effective GPR surveying of buildings.' Project 2.3 deals with identifying 'Innovative inspection procedures for effective GPR sensing and mapping of underground utilities and voids, with a focus to urban

  9. Dampened neural activity and abolition of epileptic-like activity in cortical slices by active ingredients of spices

    Science.gov (United States)

    Pezzoli, Maurizio; Elhamdani, Abdeladim; Camacho, Susana; Meystre, Julie; González, Stephanie Michlig; le Coutre, Johannes; Markram, Henry

    2014-01-01

    Active ingredients of spices (AIS) modulate neural response in the peripheral nervous system, mainly through interaction with TRP channel/receptors. The present study explores how different AIS modulate neural response in layer 5 pyramidal neurons of S1 neocortex. The AIS tested are agonists of TRPV1/3, TRPM8 or TRPA1. Our results demonstrate that capsaicin, eugenol, menthol, icilin and cinnamaldehyde, but not AITC dampen the generation of APs in a voltage- and time-dependent manner. This effect was further tested for the TRPM8 ligands in the presence of a TRPM8 blocker (BCTC) and on TRPM8 KO mice. The observable effect was still present. Finally, the influence of the selected AIS was tested on in vitro gabazine-induced seizures. Results coincide with the above observations: except for cinnamaldehyde, the same AIS were able to reduce the number, duration of the AP bursts and increase the concentration of gabazine needed to elicit them. In conclusion, our data suggests that some of these AIS can modulate glutamatergic neurons in the brain through a TRP-independent pathway, regardless of whether the neurons are stimulated intracellularly or by hyperactive microcircuitry. PMID:25359561

  10. Differential regulation of the Rac1 GTPase-activating protein (GAP) BCR during oxygen/glucose deprivation in hippocampal and cortical neurons.

    Science.gov (United States)

    Smith, Katharine R; Rajgor, Dipen; Hanley, Jonathan G

    2017-12-08

    Brain ischemia causes oxygen and glucose deprivation (OGD) in neurons, triggering a cascade of events leading to synaptic accumulation of glutamate. Excessive activation of glutamate receptors causes excitotoxicity and delayed cell death in vulnerable neurons. Following global cerebral ischemia, hippocampal CA1 pyramidal neurons are more vulnerable to injury than their cortical counterparts, but the mechanisms that underlie this difference are unclear. Signaling via Rho-family small GTPases, their upstream guanine nucleotide exchange factors, and GTPase-activating proteins (GAPs) is differentially dysregulated in response to OGD/ischemia in hippocampal and cortical neurons. Increased Rac1 activity caused by OGD/ischemia contributes to neuronal death in hippocampal neurons via diverse effects on NADPH oxidase activity and dendritic spine morphology. The Rac1 guanine nucleotide exchange factor Tiam1 mediates an OGD-induced increase in Rac1 activity in hippocampal neurons; however, the identity of an antagonistic GAP remains elusive. Here we show that the Rac1 GAP breakpoint cluster region (BCR) associates with NMDA receptors (NMDARs) along with Tiam1 and that this protein complex is more abundant in hippocampal compared with cortical neurons. Although total BCR is similar in the two neuronal types, BCR is more active in hippocampal compared with cortical neurons. OGD causes an NMDAR- and Ca 2+ -permeable AMPAR-dependent deactivation of BCR in hippocampal but not cortical neurons. BCR knockdown occludes OGD-induced Rac1 activation in hippocampal neurons. Furthermore, disrupting the Tiam1-NMDAR interaction with a fragment of Tiam1 blocks OGD-induced Tiam1 activation but has no effect on the deactivation of BCR. This work identifies BCR as a critical player in Rac1 regulation during OGD in hippocampal neurons. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Cortical activation during mental rotation in male-to-female and female-to-male transsexuals under hormonal treatment.

    Science.gov (United States)

    Carrillo, Beatriz; Gómez-Gil, Esther; Rametti, Giuseppina; Junque, Carme; Gomez, Angel; Karadi, Kazmer; Segovia, Santiago; Guillamon, Antonio

    2010-09-01

    There is strong evidence of sex differences in mental rotation tasks. Transsexualism is an extreme gender identity disorder in which individuals seek cross-gender treatment to change their sex. The aim of our study was to investigate if male-to-female (MF) and female-to-male (FM) transsexuals receiving cross-sex hormonal treatment have different patterns of cortical activation during a three-dimensional (3D) mental rotation task. An fMRI study was performed using a 3-T scan in a sample of 18 MF and 19 FM under chronic cross-sex hormonal treatment. Twenty-three males and 19 females served as controls. The general pattern of cerebral activation seen while visualizing the rotated and non-rotated figures was similar for all four groups showing strong occipito-parieto-frontal brain activation. However, compared to control males, the activation of MF transsexuals during the task was lower in the superior parietal lobe. Compared to control females, MF transsexuals showed higher activation in orbital and right dorsolateral prefrontal regions and lower activation in the left prefrontal gyrus. FM transsexuals did not differ from either the MF transsexual or control groups. Regression analyses between cerebral activation and the number of months of hormonal treatment showed a significant negative correlation in parietal, occipital and temporal regions in the MF transsexuals. No significant correlations with time were seen in the FM transsexuals. In conclusion, although we did not find a specific pattern of cerebral activation in the FM transsexuals, we have identified a specific pattern of cerebral activation during a mental 3D rotation task in MF transsexuals under cross-sex hormonal treatment that differed from control males in the parietal region and from control females in the orbital prefrontal region. The hypoactivation in MF transsexuals in the parietal region could be due to the hormonal treatment or could reflect a priori cerebral differences between MF transsexual

  12. Waiting to win: elevated striatal and orbitofrontal cortical activity during reward anticipation in euthymic bipolar disorder adults

    Science.gov (United States)

    Nusslock, Robin; Almeida, Jorge RC; Forbes, Erika E; Versace, Amelia; Frank, Ellen; LaBarbara, Edmund J; Klein, Crystal R; Phillips, Mary L

    2012-01-01

    Objective Bipolar disorder may be characterized by a hypersensitivity to reward-relevant stimuli, potentially underlying the emotional lability and dysregulation that characterizes the illness. In parallel, research highlights the predominant role of striatal and orbitofrontal cortical (OFC) regions in reward-processing and approach-related affect. We aimed to examine whether bipolar disorder, relative to healthy, participants displayed elevated activity in these regions during reward processing. Methods Twenty-one euthymic bipolar I disorder and 20 healthy control participants with no lifetime history of psychiatric disorder underwent functional magnetic resonance imaging (fMRI) scanning during a card-guessing paradigm designed to examine reward-related brain function to anticipation and receipt of monetary reward and loss. Data were collected using a 3T Siemens Trio scanner. Results Region-of-interest analyses revealed that bipolar disorder participants displayed greater ventral striatal and right-sided orbitofrontal [Brodmann area (BA) 11] activity during anticipation, but not outcome, of monetary reward, relative to healthy controls (p anticipation (p anticipation may represent a neural mechanism for predisposition to expansive mood and hypo/mania in response to reward-relevant cues that characterizes bipolar disorder. Our findings contrast with research reporting blunted activity in the ventral striatum during reward processing in unipolar depressed individuals, relative to healthy controls. Examination of reward-related neural activity in bipolar disorder is a promising research focus to facilitate identification of biological markers of the illness. PMID:22548898

  13. Electromagnetic modelling, inversion and data-processing techniques for GPR: ongoing activities in Working Group 3 of COST Action TU1208

    Science.gov (United States)

    Pajewski, Lara; Giannopoulos, Antonis; van der Kruk, Jan

    2015-04-01

    This work aims at presenting the ongoing research activities carried out in Working Group 3 (WG3) 'EM methods for near-field scattering problems by buried structures; data processing techniques' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. WG3 is structured in four Projects. Project 3.1 deals with 'Electromagnetic modelling for GPR applications.' Project 3.2 is concerned with 'Inversion and imaging techniques for GPR applications.' The topic of Project 3.3 is the 'Development of intrinsic models for describing near-field antenna effects, including antenna-medium coupling, for improved radar data processing using full-wave inversion.' Project 3.4 focuses on 'Advanced GPR data-processing algorithms.' Electromagnetic modeling tools that are being developed and improved include the Finite-Difference Time-Domain (FDTD) technique and the spectral domain Cylindrical-Wave Approach (CWA). One of the well-known freeware and versatile FDTD simulators is GprMax that enables an improved realistic representation of the soil/material hosting the sought structures and of the GPR antennas. Here, input/output tools are being developed to ease the definition of scenarios and the visualisation of numerical results. The CWA expresses the field scattered by subsurface two-dimensional targets with arbitrary cross-section as a sum of cylindrical waves. In this way, the interaction is taken into account of multiple scattered fields within the medium hosting the sought targets. Recently, the method has been extended to deal with through-the-wall scenarios. One of the

  14. Cortical activation patterns during long-term memory retrieval of visually or haptically encoded objects and locations.

    Science.gov (United States)

    Stock, Oliver; Röder, Brigitte; Burke, Michael; Bien, Siegfried; Rösler, Frank

    2009-01-01

    The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n=10) or haptically (haptic encoding group, n=10) had to be retrieved from long-term memory. Participants learned associations between auditorily presented words and either meaningless objects or locations in a 3-D space. During the retrieval phase one day later, participants had to decide whether two auditorily presented words shared an association with a common object or location. Thus, perceptual stimulation during retrieval was always equivalent, whereas either visually or haptically encoded object or location associations had to be reactivated. Moreover, the number of associations fanning out from each word varied systematically, enabling a parametric increase of the number of reactivated representations. Recall of visual objects predominantly activated the left superior frontal gyrus and the intraparietal cortex, whereas visually learned locations activated the superior parietal cortex of both hemispheres. Retrieval of haptically encoded material activated the left medial frontal gyrus and the intraparietal cortex in the object condition, and the bilateral superior parietal cortex in the location condition. A direct test for modality-specific effects showed that visually encoded material activated more vision-related areas (BA 18/19) and haptically encoded material more motor and somatosensory-related areas. A conjunction analysis identified supramodal and material-unspecific activations within the medial and superior frontal gyrus and the superior parietal lobe including the intraparietal sulcus. These activation patterns strongly support the idea that code-specific representations are consolidated and reactivated within anatomically distributed cell assemblies that comprise sensory and motor processing systems.

  15. A Functional Role for the Epigenetic Regulator ING1 in Activity-induced Gene Expression in Primary Cortical Neurons.

    Science.gov (United States)

    Leighton, Laura J; Zhao, Qiongyi; Li, Xiang; Dai, Chuanyang; Marshall, Paul R; Liu, Sha; Wang, Yi; Zajaczkowski, Esmi L; Khandelwal, Nitin; Kumar, Arvind; Bredy, Timothy W; Wei, Wei

    2018-01-15

    Epigenetic regulation of activity-induced gene expression involves multiple levels of molecular interaction, including histone and DNA modifications, as well as mechanisms of DNA repair. Here we demonstrate that the genome-wide deposition of inhibitor of growth family member 1 (ING1), which is a central epigenetic regulatory protein, is dynamically regulated in response to activity in primary cortical neurons. ING1 knockdown leads to decreased expression of genes related to synaptic plasticity, including the regulatory subunit of calcineurin, Ppp3r1. In addition, ING1 binding at a site upstream of the transcription start site (TSS) of Ppp3r1 depends on yet another group of neuroepigenetic regulatory proteins, the Piwi-like family, which are also involved in DNA repair. These findings provide new insight into a novel mode of activity-induced gene expression, which involves the interaction between different epigenetic regulatory mechanisms traditionally associated with gene repression and DNA repair. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Selective activation of microglia in spinal cord but not higher cortical regions following nerve injury in adult mouse

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    Shang Yuze

    2008-04-01

    Full Text Available Abstract Neuronal plasticity along the pathway for sensory transmission including the spinal cord and cortex plays an important role in chronic pain, including inflammatory and neuropathic pain. While recent studies indicate that microglia in the spinal cord are involved in neuropathic pain, a systematic study has not been performed in other regions of the central nervous system (CNS. In the present study, we used heterozygous Cx3cr1GFP/+mice to characterize the morphological phenotypes of microglia following common peroneal nerve (CPN ligation. We found that microglia showed a uniform distribution throughout the CNS, and peripheral nerve injury selectively activated microglia in the spinal cord dorsal horn and related ventral horn. In contrast, microglia was not activated in supraspinal regions of the CNS, including the anterior cingulate cortex (ACC, prefrontal cortex (PFC, primary and secondary somatosensory cortex (S1 and S2, insular cortex (IC, amygdala, hippocampus, periaqueductal gray (PAG and rostral ventromedial medulla (RVM. Our results provide strong evidence that nerve injury primarily activates microglia in the spinal cord of adult mice, and pain-related cortical plasticity is likely mediated by neurons.

  17. No difference in frontal cortical activity during an executive functioning task after acute doses of aripiprazole and haloperidol

    Directory of Open Access Journals (Sweden)

    Ingeborg eBolstad

    2015-05-01

    Full Text Available Background: Aripiprazole is an atypical antipsychotic drug that is characterized by partial dopamine D2 receptor agonism. Its pharmacodynamic profile is proposed to be beneficial in the treatment of cognitive impairment, which is prevalent in psychotic disorders. This study compared brain activation characteristics produced by aripiprazole with that of haloperidol, a typical D2 receptor antagonist, during a task targeting executive functioning.Methods: Healthy participants received an acute oral dose of haloperidol, aripiprazole or placebo before performing an executive functioning task while blood-oxygen-level-dependent (BOLD functional magnetic resonance imaging (fMRI was carried out. Results: There was a tendency towards reduced performance in the aripiprazole group compared to the two other groups. The image analysis yielded a strong task-related BOLD-fMRI response within each group. An uncorrected between-group analysis showed that aripiprazole challenge resulted in stronger activation in the frontal and temporal gyri and the putamen compared with haloperidol challenge, but after correcting for multiple testing there was no significant group difference. Conclusion: No significant group differences between aripiprazole and haloperidol in frontal cortical activation were obtained when corrected for multiple comparisons.This study is registered in ClinicalTrials.gov (identifier: 2009-016222-14; https://clinicaltrials.gov/.

  18. Design and testing of Ground Penetrating Radar equipment dedicated for civil engineering applications: ongoing activities in Working Group 1 of COST Action TU1208

    Science.gov (United States)

    Pajewski, Lara; Manacorda, Guido; Persico, Raffaele

    2015-04-01

    This work aims at presenting the ongoing research activities carried out in Working Group 1 'Novel GPR instrumentation' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Working Group 1 (WG1) of the Action focuses on the development of innovative GPR equipment dedicated for civil engineering applications. It includes three Projects. Project 1.1 is focused on the 'Design, realisation and optimisation of innovative GPR equipment for the monitoring of critical transport infrastructures and buildings, and for the sensing of underground utilities and voids.' Project 1.2 is concerned with the 'Development and definition of advanced testing, calibration and stability procedures and protocols, for GPR equipment.' Project 1.3 deals with the 'Design, modelling and optimisation of GPR antennas.' During the first year of the Action, WG1 Members coordinated between themselves to address the state of the art and open problems in the scientific fields identified by the above-mentioned Projects [1, 2]. In carrying our this work, the WG1 strongly benefited from the participation of IDS Ingegneria dei Sistemi, one of the biggest GPR manufacturers, as well as from the contribution of external experts as David J. Daniels and Erica Utsi, sharing with the Action Members their wide experience on GPR technology and methodology (First General Meeting, July 2013). The synergy with WG2 and WG4 of the Action was useful for a deep understanding of the problems, merits and limits of available GPR equipment, as well as to discuss how to quantify the reliability of GPR results. An

  19. Cortical Activations during a Computer-Based Fraction Learning Game: Preliminary Results from a Pilot Study

    Science.gov (United States)

    Baker, Joseph M.; Martin, Taylor; Aghababyan, Ani; Armaghanyan, Armen; Gillam, Ronald

    2015-01-01

    Advances in educational neuroscience have made it possible for researchers to conduct studies that observe concurrent behavioral (i.e., task performance) and neural (i.e., brain activation) responses to naturalistic educational activities. Such studies are important because they help educators, clinicians, and researchers to better understand the…

  20. Phase-dependent effects of stimuli locked to oscillatory activity in cultured cortical networks

    NARCIS (Netherlands)

    Stegenga, J.; le Feber, Jakob; Marani, Enrico; Rutten, Wim

    The archetypal activity pattern in cultures of dissociated neurons is spontaneous network-wide bursting. Bursts may interfere with controlled activation of synaptic plasticity, but can be suppressed by the application of stimuli at a sufficient rate. We sinusoidally modulated (4 Hz) the pulse rate

  1. Change of cortical foot activation following 70 days of head down bed rest.

    Science.gov (United States)

    Yuan, Peng; Koppelmans, Vincent; Reuter-Lorenz, Patricia; De Dios, Yiri; Gadd, Nichole; Riascos, Roy; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael D

    2018-02-28

    Head-down tilt bed rest (HDBR) has been used as a spaceflight analog to study some of the effects of microgravity on human physiology, cognition, and sensorimotor functions. Previous studies have reported declines in balance control and functional mobility after spaceflight and HDBR. Here we investigated how the brain activation for foot movement changed with HDBR. Eighteen healthy men participated in the current HDBR study. They were in a 6{degree sign} head-down tilt position continuously for 70 days. Functional MRI scans were acquired to estimate brain activation for foot movement pre-, during- and post-HDBR. Another eleven healthy males who did not undergo HDBR participated as control subjects and were scanned at four time points. In the HDBR subjects, the cerebellum, fusiform gyrus, hippocampus, and middle occipital gyrus exhibited HDBR-related increases in activation for foot tapping, whereas no HDBR-associated activation decreases were found. For the control subjects, activation for foot tapping decreased across sessions in a couple of cerebellar regions, while no activation increase with session was found. Furthermore, we observed that less HDBR-related declines in functional mobility and balance control were associated with greater pre-to-post HDBR increases in brain activation for foot movement in several cerebral and cerebellar regions. Our results suggest that more neural control is needed for foot movement as a result of HDBR.

  2. Activation of extrastriate and frontal cortical areas by visual words and word-like stimuli

    International Nuclear Information System (INIS)

    Petersen, S.E.; Fox, P.T.; Snyder, A.Z.; Raichle, M.E.

    1990-01-01

    Visual presentation of words activates extrastriate regions of the occipital lobes of the brain. When analyzed by positron emission tomography (PET), certain areas in the left, medial extrastriate visual cortex were activated by visually presented pseudowords that obey English spelling rules, as well as by actual words. These areas were not activated by nonsense strings of letters or letter-like forms. Thus visual word form computations are based on learned distinctions between words and nonwords. In addition, during passive presentation of words, but not pseudowords, activation occurred in a left frontal area that is related to semantic processing. These findings support distinctions made in cognitive psychology and computational modeling between high-level visual and semantic computations on single words and describe the anatomy that may underlie these distinctions

  3. Individual differences in approach motivation, resting-state frontal cortical activity and attentional scope

    NARCIS (Netherlands)

    Boksem, M.A.S.; Kostermans, E.; Tops, M.; de Cremer, D.

    2012-01-01

    Recent research has demonstrated that individual differences in approach motivation modulate attentional scope. In turn, approach and inhibition have been related to different neural systems that are associated with asymmetries in relative frontal activity (RFA). Here, we investigated whether such

  4. Disturbed functional connectivity of cortical activation during semantic discrimination in patients with schizophrenia and subjects at genetic high-risk.

    Science.gov (United States)

    Li, Xiaobo; Branch, Craig A; Nierenberg, Jay; Delisi, Lynn E

    2010-03-01

    Schizophrenia has a strong genetic component that is relevant to the understanding of the pathophysiology of the syndrome. Thus, recent investigations have shifted from studies of diagnosed patients with schizophrenia to examining their unaffected relatives. Previous studies found that during language processing, relatives thought to be at genetic high-risk for the disorder exhibit aberrant functional activation in regions of language processing, specifically in the left inferior frontal gyrus (Broca's area). However, functional connectivity among the regions involved in language pathways is not well understood. In this study, we examined the functional connectivity between a seed located in Broca's area and the remainder of the brain during a visual lexical decision task, in 20 schizophrenia patients, 21 subjects at genetic high risk for the disorder and 21 healthy controls. Both the high-risk subjects and patients showed significantly reduced activation correlations between seed and regions related to visual language processing. Compared to the high-risk subjects, the schizophrenia patients showed even fewer regions that were correlated with the seed regions. These results suggest that there is aberrant functional connectivity within cortical language circuitry in high-risk subjects and patients with schizophrenia. Broca's area, which is one of the important regions for language processing in healthy controls, had a significantly reduced role in the high-risk subjects and patients with schizophrenia. Our findings are consistent with the existence of an underlying biological disturbance that begins in genetically at risk individuals and progresses to a greater extent in those who eventually develop schizophrenia.

  5. The sequence of cortical activity inferred by response latency variability in the human ventral pathway of face processing.

    Science.gov (United States)

    Lin, Jo-Fu Lotus; Silva-Pereyra, Juan; Chou, Chih-Che; Lin, Fa-Hsuan

    2018-04-11

    Variability in neuronal response latency has been typically considered caused by random noise. Previous studies of single cells and large neuronal populations have shown that the temporal variability tends to increase along the visual pathway. Inspired by these previous studies, we hypothesized that functional areas at later stages in the visual pathway of face processing would have larger variability in the response latency. To test this hypothesis, we used magnetoencephalographic data collected when subjects were presented with images of human faces. Faces are known to elicit a sequence of activity from the primary visual cortex to the fusiform gyrus. Our results revealed that the fusiform gyrus showed larger variability in the response latency compared to the calcarine fissure. Dynamic and spectral analyses of the latency variability indicated that the response latency in the fusiform gyrus was more variable than in the calcarine fissure between 70 ms and 200 ms after the stimulus onset and between 4 Hz and 40 Hz, respectively. The sequential processing of face information from the calcarine sulcus to the fusiform sulcus was more reliably detected based on sizes of the response variability than instants of the maximal response peaks. With two areas in the ventral visual pathway, we show that the variability in response latency across brain areas can be used to infer the sequence of cortical activity.

  6. The influence of encoding strategy on episodic memory and cortical activity in schizophrenia.

    Science.gov (United States)

    Bonner-Jackson, Aaron; Haut, Kristen; Csernansky, John G; Barch, Deanna M

    2005-07-01

    Recent work suggests that episodic memory deficits in schizophrenia may be related to disturbances of encoding or retrieval. Schizophrenia patients appear to benefit from instruction in episodic memory strategies. We tested the hypothesis that providing effective encoding strategies to schizophrenia patients enhances encoding-related brain activity and recognition performance. Seventeen schizophrenia patients and 26 healthy comparison subjects underwent functional magnetic resonance imaging scans while performing incidental encoding tasks of words and faces. Subjects were required to make either deep (abstract/concrete) or shallow (alphabetization) judgments for words and deep (gender) judgments for faces, followed by subsequent recognition tests. Schizophrenia and comparison subjects recognized significantly more words encoded deeply than shallowly, activated regions in inferior frontal cortex (Brodmann area 45/47) typically associated with deep and successful encoding of words, and showed greater left frontal activation for the processing of words compared with faces. However, during deep encoding and material-specific processing (words vs. faces), participants with schizophrenia activated regions not activated by control subjects, including several in prefrontal cortex. Our findings suggest that a deficit in use of effective strategies influences episodic memory performance in schizophrenia and that abnormalities in functional brain activation persist even when such strategies are applied.

  7. Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

    Science.gov (United States)

    Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

    2014-10-15

    This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Cortical Activation during Landmark-Centered vs. Gaze-Centered Memory of Saccade Targets in the Human: An FMRI Study

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2017-06-01

    Full Text Available A remembered saccade target could be encoded in egocentric coordinates such as gaze-centered, or relative to some external allocentric landmark that is independent of the target or gaze (landmark-centered. In comparison to egocentric mechanisms, very little is known about such a landmark-centered representation. Here, we used an event-related fMRI design to identify brain areas supporting these two types of spatial coding (i.e., landmark-centered vs. gaze-centered for target memory during the Delay phase where only target location, not saccade direction, was specified. The paradigm included three tasks with identical display of visual stimuli but different auditory instructions: Landmark Saccade (remember target location relative to a visual landmark, independent of gaze, Control Saccade (remember original target location relative to gaze fixation, independent of the landmark, and a non-spatial control, Color Report (report target color. During the Delay phase, the Control and Landmark Saccade tasks activated overlapping areas in posterior parietal cortex (PPC and frontal cortex as compared to the color control, but with higher activation in PPC for target coding in the Control Saccade task and higher activation in temporal and occipital cortex for target coding in Landmark Saccade task. Gaze-centered directional selectivity was observed in superior occipital gyrus and inferior occipital gyrus, whereas landmark-centered directional selectivity was observed in precuneus and midposterior intraparietal sulcus. During the Response phase after saccade direction was specified, the parietofrontal network in the left hemisphere showed higher activation for rightward than leftward saccades. Our results suggest that cortical activation for coding saccade target direction relative to a visual landmark differs from gaze-centered directional selectivity for target memory, from the mechanisms for other types of allocentric tasks, and from the directionally

  9. IGF-1 and insulin exert opposite actions on ClC-K2 activity in the cortical collecting ducts.

    Science.gov (United States)

    Zaika, Oleg; Mamenko, Mykola; Boukelmoune, Nabila; Pochynyuk, Oleh

    2015-01-01

    Despite similar stimulatory actions on the epithelial sodium channel (ENaC)-mediated sodium reabsorption in the distal tubule, insulin promotes kaliuresis, whereas insulin-like growth factor-1 (IGF-1) causes a reduction in urinary potassium levels. The factors contributing to this phenomenon remain elusive. Electrogenic distal nephron ENaC-mediated Na(+) transport establishes driving force for Cl(-) reabsorption and K(+) secretion. Using patch-clamp electrophysiology, we document that a Cl(-) channel is highly abundant on the basolateral plasma membrane of intercalated cells in freshly isolated mouse cortical collecting duct (CCD) cells. The channel has characteristics attributable to the ClC-K2: slow gating kinetics, conductance ∼10 pS, voltage independence, Cl(-)>NO3 (-) anion selectivity, and inhibition/activation by low/high pH, respectively. IGF-1 (100 and 500 nM) acutely stimulates ClC-K2 activity in a reversible manner. Inhibition of PI3-kinase (PI3-K) with LY294002 (20 μM) abrogates activation of ClC-K2 by IGF-1. Interestingly, insulin (100 nM) reversibly decreases ClC-K2 activity in CCD cells. This inhibitory action is independent of PI3-K and is mediated by stimulation of a mitogen-activated protein kinase-dependent cascade. We propose that IGF-1, by stimulating ClC-K2 channels, promotes net Na(+) and Cl(-) reabsorption, thus reducing driving force for potassium secretion by the CCD. In contrast, inhibition of ClC-K2 by insulin favors coupling of Na(+) reabsorption with K(+) secretion at the apical membrane contributing to kaliuresis. Copyright © 2015 the American Physiological Society.

  10. Type II thyroplasty changes cortical activation in patients with spasmodic dysphonia.

    Science.gov (United States)

    Tateya, Ichiro; Omori, Koichi; Kojima, Hisayoshi; Naito, Yasushi; Hirano, Shigeru; Yamashita, Masaru; Ito, Juichi

    2015-04-01

    Spasmodic dysphonia (SD) is a complex neurological communication disorder characterized by a choked, strain-strangled vocal quality with voice stoppages in phonation. Its symptoms are exacerbated by situations where communication failures are anticipated, and reduced when talking with animals or small children. Symptoms are also reduced following selected forms of treatment. It is reasonable to assume that surgical alteration reducing symptoms would also alter brain activity, though demonstration of such a phenomenon has not been documented. The objective of this study is to reveal brain activity of SD patients before and after surgical treatment. We performed lateralization thyroplasties on three adductor SD patients and compared pre- and post-operative positron emission tomography recordings made during vocalization. Pre-operatively, cordal supplementary motor area (SMA), bilateral auditory association areas, and thalamus were activated while reading aloud. Such activity was not observed in normal subjects. Type II thyroplasty was performed according to Isshiki's method and the strained voice was significantly reduced or eliminated in all three patients. Post-operative PET showed normal brain activation pattern with a significant decrease in cordal SMA, bilateral auditory association areas and thalamus, and a significant increase in rostral SMA compared with pre-operative recordings. This is the first report showing that treatment to a peripheral organ, which reverses voice symptoms, also reverses dysfunctional patterns of the central nervous system in patients with SD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Depression and anxious apprehension distinguish frontocingulate cortical activity during top-down attentional control.

    Science.gov (United States)

    Silton, Rebecca Levin; Heller, Wendy; Engels, Anna S; Towers, David N; Spielberg, Jeffrey M; Edgar, J Christopher; Sass, Sarah M; Stewart, Jennifer L; Sutton, Bradley P; Banich, Marie T; Miller, Gregory A

    2011-05-01

    A network consisting of left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC) has been implicated in top-down attentional control. Few studies have systematically investigated how this network is altered in psychopathology, despite evidence that depression and anxiety are associated with attentional control impairments. Functional MRI and dense-array event-related brain potential (ERP) data were collected in separate sessions from 100 participants during a color-word Stroop task. Functional MRI results guided ERP source modeling to characterize the time course of activity in LDLPFC (300-440 ms) and dACC (520-680 ms). At low levels of depression, LDLPFC activity was indirectly related to Stroop interference and only via dACC activity. In contrast, at high levels of depression, dACC did not play an intervening role, and increased LDLPFC activity was directly related to decreased Stroop interference. Specific to high levels of anxious apprehension, higher dACC activity was related to more Stroop interference. Results indicate that depression and anxious apprehension modulate temporally and functionally distinct aspects of the frontocingulate network involved in top-down attention control.

  12. rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

    Science.gov (United States)

    Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

    2013-01-01

    Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

  13. Urinary albumin and interleukin-8 levels are not good indicators of ongoing vesicoureteral reflux in children who have no active urinary tract infection.

    Science.gov (United States)

    Badeli, Hamidreza; khoshnevis, Termeh; Hassanzadeh Rad, Afagh; Sadeghi, Mehrdad

    2013-01-01

    Vesicoureteral reflux (VUR) is a risk factor for kidney scarring, hypertension and declining renal function. Standard diagnostic methods are invasive and can cause exposure to radiation and urinary tract infections (UTIs). We aimed to investigate urine albumin and interleukin-8 levels as markers of ongoing VUR and renal damage in children without UTIs. Random urine samples were collected from 51 children, including 16 children with VUR (group A), 17 children with resolved VUR (group B) and 18 normal children (group C). The diagnosis of VUR or resolved VUR was confirmed by voiding cystourethrogram (VCUG) or direct radionuclide cystography (DRNC). All children had normal kidney function and had no evidence of UTI in the preceding three months. Random urine specimens were assayed for albumin (Alb), creatinine (Cr) and interleukin-8 (IL-8) and mean values were compared by one way ANOVA. In groups A and B, the mean age at first UTI was 31.7 ± 2.4 and 27 ± 2.0 months respectively. In group A, the mean duration between VUR diagnosis and study entrance was 30 ± 9.1 months. In group B, the mean duration between VUR diagnosis and recovery was 19.9 ± 1.3 months. Overall, 76.4% of affected children had bilateral VUR and 41.2% had severe VUR. There were no significant differences in urinary Alb, IL-8, Alb/Cr and IL-8/Cr between the three groups. The current study does not support the hypothesis that microalbuminuria or urinary IL-8 are good indicators of ongoing VUR and renal injury in children.

  14. Cortical activity, ionic homeostasis, and acidosis during rat brain repetitive ischemia.

    Science.gov (United States)

    Matsumoto, T; Obrenovitch, T P; Parkinson, N A; Symon, L

    1990-08-01

    Recent data strongly suggest that repetitive ischemic episodes have an adverse cumulative effect on development of edema and tissue damage. We wanted to assess further whether special risks such as exacerbation of extracellular acidification reflecting progressive exhaustion of the capacity to buffer H+ in the extracellular space are associated with repeated short ischemic insults. We monitored spontaneous electrical activity, extracellular direct-current potential, extracellular H+ activity, and tissue PCO2 in the cerebral cortex of rats subjected to four cycles of 3-minute ischemia produced by four-vessel occlusion with 27-minute reperfusion after each insult. Except for electrical activity, which failed to recover fully from the first ischemic insult, all parameters returned to a level close to normal after each reperfusion. Changes during ischemia did not evolve with repetition of the insult. Electrical silence occurred within approximately 20 seconds after the onset of each ischemic episode and always preceded the steep drop of direct-current potential, indicating ischemic depolarization. Each four-vessel occlusion immediately initiated a steep rise of tissue PCO2 and extracellular H+ activity, with extracellular H+ activity reaching a maximum within approximately 145 seconds. Changes in extracellular H+ activity during each recirculation period consistently included an additional and short-lasting increase associated with repolarization, a rapid decrease closely related to that of tissue PCO2, and a slow progressive return to normal. These results suggest that short, repetitive ischemic episodes severe enough to produce cell membrane depolarization and maximum acidosis of the neuronal microenvironment do not have a deleterious cumulative effect on the studied parameters, in particular, on interstitial acidosis.

  15. Fluency-dependent cortical activation associated with speech production and comprehension in second language learners.

    Science.gov (United States)

    Shimada, K; Hirotani, M; Yokokawa, H; Yoshida, H; Makita, K; Yamazaki-Murase, M; Tanabe, H C; Sadato, N

    2015-08-06

    This functional magnetic resonance imaging (fMRI) study investigated the brain regions underlying language task performance in adult second language (L2) learners. Specifically, we identified brain regions where the level of activation was associated with L2 fluency levels. Thirty Japanese-speaking adults participated in the study. All participants were L2 learners of English and had achieved varying levels of fluency, as determined by a standardized L2 English proficiency test, the Versant English Test (Pearson Education Inc., 2011). When participants performed the oral sentence building task from the production tasks administered, the dorsal part of the left inferior frontal gyrus (dIFG) showed activation patterns that differed depending on the L2 fluency levels: The more fluent the participants were, the more dIFG activation decreased. This decreased activation of the dIFG might reflect the increased automaticity of a syntactic building process. In contrast, when participants performed an oral story comprehension task, the left posterior superior temporal gyrus (pSTG) showed increased activation with higher fluency levels. This suggests that the learners with higher L2 fluency were actively engaged in post-syntactic integration processing supported by the left pSTG. These data imply that L2 fluency predicts neural resource allocation during language comprehension tasks as well as in production tasks. This study sheds light on the neural underpinnings of L2 learning by identifying the brain regions recruited during different language tasks across different modalities (production vs. comprehension). Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Modulation of Cortical-subcortical Networks in Parkinson’s Disease by Applied Field Effects

    Directory of Open Access Journals (Sweden)

    Christopher William Hess

    2013-09-01

    Full Text Available Studies suggest that endogenous field effects may play a role in neuronal oscillations and communication. Non-invasive transcranial electrical stimulation with low-intensity currents can also have direct effects on the underlying cortex as well as distant network effects. While Parkinson's disease (PD is amenable to invasive neuromodulation in the basal ganglia by deep brain stimulation, techniques of non-invasive neuromodulation like transcranial direct current stimulation (tDCS and transcranial alternating current stimulation (tACS are being investigated as possible therapies. tDCS and tACS have the potential to influence the abnormal cortical-subcortical network activity that occurs in PD through sub-threshold changes in cortical excitability or through entrainment or disruption of ongoing rhythmic cortical activity. This may allow for the targeting of specific features of the disease involving abnormal oscillatory activity, as well as the enhancement of potential cortical compensation for basal ganglia dysfunction and modulation of cortical plasticity in neurorehabilitation. However, little is currently known about how cortical stimulation will affect subcortical structures, the size of any effect, and the factors of stimulation that will influence these effects.

  17. Cortical Activation during Action Observation, Action Execution, and Interpersonal Synchrony in Adults: A functional Near-Infrared Spectroscopy (fNIRS Study

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    Anjana N. Bhat

    2017-09-01

    Full Text Available Introduction: Humans engage in Interpersonal Synchrony (IPS as they synchronize their own actions with that of a social partner over time. When humans engage in imitation/IPS behaviors, multiple regions in the frontal, temporal, and parietal cortices are activated including the putative Mirror Neuron Systems (Iacoboni, 2005; Buxbaum et al., 2014. In the present study, we compared fNIRS-based cortical activation patterns across three conditions of action observation (“Watch” partner, action execution (“Do” on your own, and IPS (move “Together”.Methods: Fifteen typically developing adults completed a reach and cleanup task with the right arm while cortical activation was examined using a 24-channel, Hitachi fNIRS system. Each adult completed 8 trials across three conditions (Watch, Do, and Together. For each fNIRS channel, we obtained oxy hemoglobin (HbO2 and deoxy hemoglobin (HHb profiles. Spatial registration methods were applied to localize the cortical regions underneath each channel and to define six regions of interest (ROIs, right and left supero-anterior (SA or pre/post-central gyri, infero-posterior (IP or angular/supramarginal gyri, and infero-anterior (IA or superior/middle temporal gyri regions.Results: In terms of task-related differences, the majority of the ROIs were more active during Do and Together compared to Watch. Only the right/ipsilateral fronto-parietal and inferior parietal cortices had greater activation during Together compared to Do.Conclusions: The similarities in cortical activation between action execution and IPS suggest that neural control of IPS is more similar to its execution than observational aspects. To be clear, the more complex the actions performed, the more difficult the IPS behaviors. Secondly, IPS behaviors required slightly more right-sided activation (vs. execution/observation suggesting that IPS is a higher-order process involving more bilateral activation compared to its sub

  18. The Influence of verbalization on the pattern of cortical activation during mental arithmetic

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    Zarnhofer Sabrina

    2012-03-01

    Full Text Available Abstract Background The aim of the present functional magnetic resonance imaging (fMRI study at 3 T was to investigate the influence of the verbal-visual cognitive style on cerebral activation patterns during mental arithmetic. In the domain of arithmetic, a visual style might for example mean to visualize numbers and (intermediate results, and a verbal style might mean, that numbers and (intermediate results are verbally repeated. In this study, we investigated, first, whether verbalizers show activations in areas for language processing, and whether visualizers show activations in areas for visual processing during mental arithmetic. Some researchers have proposed that the left and right intraparietal sulcus (IPS, and the left angular gyrus (AG, two areas involved in number processing, show some domain or modality specificity. That is, verbal for the left AG, and visual for the left and right IPS. We investigated, second, whether the activation in these areas implied in number processing depended on an individual's cognitive style. Methods 42 young healthy adults participated in the fMRI study. The study comprised two functional sessions. In the first session, subtraction and multiplication problems were presented in an event-related design, and in the second functional session, multiplications were presented in two formats, as Arabic numerals and as written number words, in an event-related design. The individual's habitual use of visualization and verbalization during mental arithmetic was assessed by a short self-report assessment. Results We observed in both functional sessions that the use of verbalization predicts activation in brain areas associated with language (supramarginal gyrus and auditory processing (Heschl's gyrus, Rolandic operculum. However, we found no modulation of activation in the left AG as a function of verbalization. Conclusions Our results confirm that strong verbalizers use mental speech as a form of mental

  19. The pairwise phase consistency in cortical network and its relationship with neuronal activation

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    Wang Daming

    2017-01-01

    Full Text Available Gamma-band neuronal oscillation and synchronization with the range of 30-90 Hz are ubiquitous phenomenon across numerous brain areas and various species, and correlated with plenty of cognitive functions. The phase of the oscillation, as one aspect of CTC (Communication through Coherence hypothesis, underlies various functions for feature coding, memory processing and behaviour performing. The PPC (Pairwise Phase Consistency, an improved coherence measure, statistically quantifies the strength of phase synchronization. In order to evaluate the PPC and its relationships with input stimulus, neuronal activation and firing rate, a simplified spiking neuronal network is constructed to simulate orientation columns in primary visual cortex. If the input orientation stimulus is preferred for a certain orientation column, neurons within this corresponding column will obtain higher firing rate and stronger neuronal activation, which consequently engender higher PPC values, with higher PPC corresponding to higher firing rate. In addition, we investigate the PPC in time resolved analysis with a sliding window.

  20. Glycine Receptor Activation Impairs ATP-Induced Calcium Transients in Cultured Cortical Astrocytes

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    Tatiana P. Morais

    2018-01-01

    Full Text Available In central nervous system, glycine receptor (GlyR is mostly expressed in the spinal cord and brainstem, but glycinergic transmission related elements have also been identified in the brain. Astrocytes are active elements at the tripartite synapse, being responsible for the maintenance of brain homeostasis and for the fine-tuning of synaptic activity. These cells communicate, spontaneously or in response to a stimulus, by elevations in their cytosolic calcium (calcium transients, Ca2+T that can be propagated to other cells. How these Ca2+T are negatively modulated is yet poorly understood. In this work, we evaluated GlyR expression and its role on calcium signaling modulation in rat brain astrocytes. We first proved that GlyR, predominantly subunits α2 and β, was expressed in brain astrocytes and its localization was confirmed in the cytoplasm and astrocytic processes by immunohistochemistry assays. Calcium imaging experiments in cultured astrocytes showed that glycine (500 μM, a GlyR agonist, caused a concentration-dependent reduction in ATP-induced Ca2+T, an effect abolished by the GlyR antagonist, strychnine (0.8 μM, as well as by nocodazole (1 μM, known to impair GlyR anchorage to the plasma membrane. This effect was mimicked by activation of GABAAR, another Cl--permeable channel. In summary, we demonstrated that GlyR activation in astrocytes mediates an inhibitory effect upon ATP induced Ca2+T, which most probably involves changes in membrane permeability to Cl- and requires GlyR anchorage at the plasma membrane. GlyR in astrocytes may thus be part of a mechanism to modulate astrocyte-to-neuron communication.

  1. Oestrogen influences on mitochondrial gene expression and respiratory chain activity in cortical and mesencephalic astrocytes.

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    Araújo, G W; Beyer, C; Arnold, S

    2008-07-01

    The regulation of mitochondrial energy metabolism plays an essential role in the central nervous system (CNS). Abnormalities of the mitochondrial respiratory chain often accompany neurodegenerative diseases. This makes mitochondria a perfect target for strategies of cellular protection against toxic compounds and pathological conditions. Steroid hormones, such as oestrogen, are well-known to fulfil a protective role in the brain during ischaemic and degenerative processes. Because astrocytes function as the major energy supplier in the CNS, we have analysed oestrogen effects on the mitochondrial respiratory chain of this cell type. In our studies, we applied semi- and quantitative polymerase chain reaction analysis of gene expression and polarographic measurements of the respiratory chain activity of mitochondria. We observed that structural and functional properties were regulated dependent on the oestrogen exposure time and the brain region, but independent of the nuclear oestrogen receptors. We could demonstrate that long-term oestrogen exposure increases the subunit gene expression of respiratory chain complexes and the mitochondrial DNA content, thereby indicating an up-regulation of the amount of mitochondria per cell together with an increase of mitochondrial energy production. This could represent an important indirect mechanism by which long-term oestrogen exposure protects neurones from cell death under neurotoxic conditions. On the other hand, we observed short-term effects of oestrogen on the activity of mitochondrial, proton-pumping respiratory chain complexes. In astrocytes from the cortex, respiratory chain activity was decreased, whereas it was increased in astrocytes from the mesencephalon. An increased production of reactive oxygen species would be the consequence of an increased respiratory chain activity in mesencephalic astrocytes. This could explain the different efficiencies of oestrogen-mediated short-term protection in distinct brain

  2. The embodiment of emotion: language use during the feeling of social emotions predicts cortical somatosensory activity.

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    Saxbe, Darby E; Yang, Xiao-Fei; Borofsky, Larissa A; Immordino-Yang, Mary Helen

    2013-10-01

    Complex social emotions involve both abstract cognitions and bodily sensations, and individuals may differ on their relative reliance on these. We hypothesized that individuals' descriptions of their feelings during a semi-structured emotion induction interview would reveal two distinct psychological styles-a more abstract, cognitive style and a more body-based, affective style-and that these would be associated with somatosensory neural activity. We examined 28 participants' open-ended verbal responses to admiration- and compassion-provoking narratives in an interview and BOLD activity to the same narratives during subsequent functional magnetic resonance imaging scanning. Consistent with hypotheses, individuals' affective and cognitive word use were stable across emotion conditions, negatively correlated and unrelated to reported emotion strength in the scanner. Greater use of affective relative to cognitive words predicted more activation in SI, SII, middle anterior cingulate cortex and insula during emotion trials. The results suggest that individuals' verbal descriptions of their feelings reflect differential recruitment of neural regions supporting physical body awareness. Although somatosensation has long been recognized as an important component of emotion processing, these results offer 'proof of concept' that individual differences in open-ended speech reflect different processing styles at the neurobiological level. This study also demonstrates SI involvement during social emotional experience.

  3. Web addiction in the brain: Cortical oscillations, autonomic activity, and behavioral measures.

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    Balconi, Michela; Campanella, Salvatore; Finocchiaro, Roberta

    2017-09-01

    Background and aims Internet addiction (IA) was recently defined as a disorder tagging both the impulse control and the reward systems. Specifically, inhibitory deficits and reward bias were considered highly relevant in IA. This research aims to examine the electrophysiological correlates and autonomic activity [skin conductance response (SCR) and heart rate] in two groups of young subjects (N = 25), with high or low IA profile [tested by the Internet Addiction Test (IAT)], with specific reference to gambling behavior. Methods Oscillatory brain activity (delta, theta, alpha, beta, and gamma) and autonomic and behavioral measures [response times (RTs) and error rates (ERs)] were acquired during the performance of a Go/NoGo task in response to high-rewarding (online gambling videos and video games) or neutral stimuli. Results A better performance (reduced ERs and reduced RTs) was revealed for high IAT in the case of NoGo trials representing rewarding cues (inhibitory control condition), probably due to a "gain effect" induced by the rewarding condition. In addition, we also observed for NoGo trials related to gambling and video games stimuli that (a) increased low-frequency band (delta and theta) and SCR and (b) a specific lateralization effect (more left-side activity) delta and theta in high IAT. Discussion Both inhibitory control deficits and reward bias effect were considered to explain IA.

  4. Working memory for vibrotactile frequencies: comparison of cortical activity in blind and sighted individuals.

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    Burton, Harold; Sinclair, Robert J; Dixit, Sachin

    2010-11-01

    In blind, occipital cortex showed robust activation to nonvisual stimuli in many prior functional neuroimaging studies. The cognitive processes represented by these activations are not fully determined, although a verbal recognition memory role has been demonstrated. In congenitally blind and sighted (10 per group), we contrasted responses to a vibrotactile one-back frequency retention task with 5-s delays and a vibrotactile amplitude-change task; both tasks involved the same vibration parameters. The one-back paradigm required continuous updating for working memory (WM). Findings in both groups confirmed roles in WM for right hemisphere dorsolateral prefrontal (DLPFC) and dorsal/ventral attention components of posterior parietal cortex. Negative findings in bilateral ventrolateral prefrontal cortex suggested task performance without subvocalization. In bilateral occipital cortex, blind showed comparable positive responses to both tasks, whereas WM evoked large negative responses in sighted. Greater utilization of attention resources in blind were suggested as causing larger responses in dorsal and ventral attention systems, right DLPFC, and persistent responses across delays between trials in somatosensory and premotor cortex. In sighted, responses in somatosensory and premotor areas showed iterated peaks matched to stimulation trial intervals. The findings in occipital cortex of blind suggest that tactile activations do not represent cognitive operations for nonverbal WM task. However, these data suggest a role in sensory processing for tactile information in blind that parallels a similar contribution for visual stimuli in occipital cortex of sighted. © 2010 Wiley-Liss, Inc.

  5. 'Visual' cortical activation induced by acupuncture at vision-related acupoint: A fMRI study

    International Nuclear Information System (INIS)

    Yan, B.; Shan, B.C.; Zhi, L.H.; Li, K.; Lu, N.; Li, L.; Liu, H.

    2005-01-01

    It has attracted attention recently that acupuncture at vision-related acupoints, which are used to treat eye diseases according to Traditional Chinese Medicine (TCM), could activate the visual cortex. Cho and colleagues have reported that acupuncture at vision-related acupoints in the foot, activate the visual cortex bilaterally. Similar results were reported by Siedentopf and coworkers using laser acupuncture. However, Gareus et al. did not get the result, In this study, manual acupuncture was used to examine the response of central nervous system (CNS) to acupuncture at Liv3, one of important acupoints used to treat eye-related disease in clinic. To avoid the non-specific factors such as pain and anxiety, a sham acupoint which is approximately 10 mm anterior to Liv3 and innervated by the same spinal segment was selected as control. The CNS response was obtained by subtracting fMRI brain images evoked by nearby 'sham' acupoint from that evoked by the 'real' acupoint. 17 healthy right handed volunteers were comprised in the study. The images were got on 1.5T MR with EPI sequence. After 62 baseline scans, a silver needle 0.30 mm in diameter and 25 mm long was inserted and twirled for 60 scans; then the needle was withdrawn while fMRI scanning continued, until a total of 402 scans were acquired. During acupuncture, the needle was twirled manually clockwise and anticlockwise at 1 Hz with 'even reinforcing and reducing' needle manipulation. The depth of needle insertion at the sham acupoint was approximately 15 mm, the same as at the real acupoint. All the points in this study were on the right foot. The data were analyzed with spm99 using random effects analysis, discrepancies in the activation areas between Liv3 and the sham acupoint were obtained at p<0.01. Acupuncture at Liv3 significantly activated Brodmann Area 19 (BA 19) bilaterally, middle temporal gyrus, cerebellum, ipsilateral posterior cingulate, parahippocampal gyrus, contralateral postcentral gyrus, and

  6. 'Visual' cortical activation induced by acupuncture at vision-related acupoint: a fMRI study

    International Nuclear Information System (INIS)

    Yan, B.; Shan, B.C.; Zhi, L.H.; Li, K.; Lu, N.; Li, L.; Liu, H.

    2005-01-01

    It has attracted attention recently that acupuncture at vision-related acupoints, which are used to treat eye diseases according to Traditional Chinese Medicine (TCM), could activate the visual cortex. Cho and colleagues have reported that acupuncture at vision-related acupoints in the foot, activate the visual cortex bilaterally. Similar results were reported by Siedentopf and coworkers using laser acupuncture. However, Gareus et al. did not get the result. In this study, manual acupuncture was used to examine the response of central nervous system (CNS) to acupuncture at Liv3, one of important acupoints used to treat eye-related disease in clinic. To avoid the non-specific factors such as pain and anxiety, a sham acupoint which is approximately 10 mm anterior to Liv3 and innervated by the same spinal segment was selected as control. The CNS response was obtained by subtracting fMRI brain images evoked by nearby 'sham' acupoint from that evoked by the 'real' acupoint. 17 healthy right handed volunteers were comprised in the study. The images were got on 1.5T MR with EPI sequence. After 62 baseline scans, a silver needle 0.30 mm in diameter and 25 mm long was inserted and twirled for 60 scans; then the needle was withdrawn while fMRI scanning continued, until a total of 402 scans were acquired. During acupuncture, the needle was twirled manually clockwise and anticlockwise at 1 Hz with 'even reinforcing and reducing' needle manipulation. The depth of needle insertion at the sham acupoint was approximately 15 mm, the same as at the real acupoint. All the points in this study were on the right foot. The data were analyzed with spm99 using random effects analysis, discrepancies in the activation areas between Liv3 and the sham acupoint were obtained at p<0.01. Acupuncture at Liv3 significantly activated Brodmann Area 19 (BA 19) bilaterally, middle temporal gyrus, cerebellum, ipsilateral posterior cingulate, parahippocampal gyrus, contralateral postcentral gyrus, and

  7. Congruence of happy and sad emotion in music and faces modifies cortical audiovisual activation.

    Science.gov (United States)

    Jeong, Jeong-Won; Diwadkar, Vaibhav A; Chugani, Carla D; Sinsoongsud, Piti; Muzik, Otto; Behen, Michael E; Chugani, Harry T; Chugani, Diane C

    2011-02-14

    The powerful emotion inducing properties of music are well-known, yet music may convey differing emotional responses depending on environmental factors. We hypothesized that neural mechanisms involved in listening to music may differ when presented together with visual stimuli that conveyed the same emotion as the music when compared to visual stimuli with incongruent emotional content. We designed this study to determine the effect of auditory (happy and sad instrumental music) and visual stimuli (happy and sad faces) congruent or incongruent for emotional content on audiovisual processing using fMRI blood oxygenation level-dependent (BOLD) signal contrast. The experiment was conducted in the context of a conventional block-design experiment. A block consisted of three emotional ON periods, music alone (happy or sad music), face alone (happy or sad faces), and music combined with faces where the music excerpt was played while presenting either congruent emotional faces or incongruent emotional faces. We found activity in the superior temporal gyrus (STG) and fusiform gyrus (FG) to be differentially modulated by music and faces depending on the congruence of emotional content. There was a greater BOLD response in STG when the emotion signaled by the music and faces was congruent. Furthermore, the magnitude of these changes differed for happy congruence and sad congruence, i.e., the activation of STG when happy music was presented with happy faces was greater than the activation seen when sad music was presented with sad faces. In contrast, incongruent stimuli diminished the BOLD response in STG and elicited greater signal change in bilateral FG. Behavioral testing supplemented these findings by showing that subject ratings of emotion in faces were influenced by emotion in music. When presented with happy music, happy faces were rated as more happy (p=0.051) and sad faces were rated as less sad (p=0.030). When presented with sad music, happy faces were rated as less

  8. Effects of transcranial direct current stimulation on language improvement and cortical activation in nonfluent variant primary progressive aphasia.

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    Wang, Jie; Wu, Dongyu; Chen, Yan; Yuan, Ying; Zhang, Meikui

    2013-08-09

    We investigate the effects of transcranial direct current stimulation (tDCS) on language improvement and cortical activation in nonfluent variant primary progressive aphasia (nfvPPA). A 67-year-old woman diagnosed as nfvPPA received sham-tDCS for 5 days over the left posterior perisylvian region (PPR) in the morning and over left Broca's area in the afternoon in Phases A1 and A2, and tDCS for 5 days with an anodal electrode over the left PPR in the morning and over left Broca's area in the afternoon in Phases B1 and B2. Auditory word comprehension, picture naming, oral word reading and word repetition subtests of the Psycholinguistic Assessment in Chinese Aphasia (PACA) were administered before and after each phase. The EEG nonlinear index of approximate entropy (ApEn) was calculated before Phase A1, and after Phases B1 and B2. Our findings revealed that the patient improved greatly in the four subtests after A-tDCS and ApEn indices increased in stimulated areas and non-stimulated areas. We demonstrated that anodal tDCS over the left PPR and Broca's area can improve language performance of nfvPPA. tDCS may be used as an alternative therapeutic tool for PPA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a 18F-FDG PET/CT study

    International Nuclear Information System (INIS)

    Chiaravalloti, Agostino; Di Pietro, Barbara; Pagani, Marco; Micarelli, Alessandro; Alessandrini, Marco; Genovesi, Giuseppe; Schillaci, Orazio

    2015-01-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two 18 F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in 18 F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation. (orig.)

  10. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a {sup 18}F-FDG PET/CT study

    Energy Technology Data Exchange (ETDEWEB)

    Chiaravalloti, Agostino; Di Pietro, Barbara [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Department of Nuclear Medicine Karolinska Hospital Stockholm, Stockholm (Sweden); Micarelli, Alessandro; Alessandrini, Marco [University Tor Vergata, Department of Medical Science and Translational Medicine, Rome (Italy); Genovesi, Giuseppe [University La Sapienza, Department of Experimental Medicine, Rome (Italy); University La Sapienza, Regional Center for Diagnosis, Treatment and Prevention of MCS, Rome (Italy); Schillaci, Orazio [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); IRCCS Neuromed, Pozzilli (Italy)

    2015-04-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two {sup 18}F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in {sup 18}F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation. (orig.)

  11. Family nurture intervention in preterm infants increases early development of cortical activity and independence of regional power trajectories.

    Science.gov (United States)

    Welch, Martha G; Stark, Raymond I; Grieve, Philip G; Ludwig, Robert J; Isler, Joseph R; Barone, Joseph L; Myers, Michael M

    2017-12-01

    Premature delivery and maternal separation during hospitalisation increase infant neurodevelopmental risk. Previously, a randomised controlled trial of Family Nurture Intervention (FNI) in the neonatal intensive care unit demonstrated improvement across multiple mother and infant domains including increased electroencephalographic (EEG) power in the frontal polar region at term age. New aims were to quantify developmental changes in EEG power in all brain regions and frequencies and correlate developmental changes in EEG power among regions. EEG (128 electrodes) was obtained at 34-44 weeks postmenstrual age from preterm infants born 26-34 weeks. Forty-four infants were treated with Standard Care and 53 with FNI. EEG power was computed in 10 frequency bands (1-48 Hz) in 10 brain regions and in active and quiet sleep. Percent change/week in EEG power was increased in FNI in 132/200 tests (p regional independence in those developmental rates of change. This study strengthens the conclusion that FNI promotes cerebral cortical development of preterm infants. The findings indicate that developmental changes in EEG may provide biomarkers for risk in preterm infants as well as proximal markers of effects of FNI. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  12. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a (18)F-FDG PET/CT study.

    Science.gov (United States)

    Chiaravalloti, Agostino; Pagani, Marco; Micarelli, Alessandro; Di Pietro, Barbara; Genovesi, Giuseppe; Alessandrini, Marco; Schillaci, Orazio

    2015-04-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two (18)F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in (18)F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation.

  13. Autophagy activation is involved in 3,4-methylenedioxymethamphetamine ('ecstasy'--induced neurotoxicity in cultured cortical neurons.

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    I-Hsun Li

    Full Text Available Autophagic (type II cell death, characterized by the massive accumulation of autophagic vacuoles in the cytoplasm of cells, has been suggested to play pathogenetic roles in cerebral ischemia, brain trauma, and neurodegenerative disorders. 3,4-Methylenedioxymethamphetamine (MDMA or ecstasy is an illicit drug causing long-term neurotoxicity in the brain. Apoptotic (type I and necrotic (type III cell death have been implicated in MDMA-induced neurotoxicity, while the role of autophagy in MDMA-elicited neurotoxicity has not been investigated. The present study aimed to evaluate the occurrence and contribution of autophagy to neurotoxicity in cultured rat cortical neurons challenged with MDMA. Autophagy activation was monitored by expression of microtubule-associated protein 1 light chain 3 (LC3; an autophagic marker using immunofluorescence and western blot analysis. Here, we demonstrate that MDMA exposure induced monodansylcadaverine (MDC- and LC3B-densely stained autophagosome formation and increased conversion of LC3B-I to LC3B-II, coinciding with the neurodegenerative phase of MDMA challenge. Autophagy inhibitor 3-methyladenine (3-MA pretreatment significantly attenuated MDMA-induced autophagosome accumulation, LC3B-II expression, and ameliorated MDMA-triggered neurite damage and neuronal death. In contrast, enhanced autophagy flux by rapamycin or impaired autophagosome clearance by bafilomycin A1 led to more autophagosome accumulation in neurons and aggravated neurite degeneration, indicating that excessive autophagosome accumulation contributes to MDMA-induced neurotoxicity. Furthermore, MDMA induced phosphorylation of AMP-activated protein kinase (AMPK and its downstream unc-51-like kinase 1 (ULK1, suggesting the AMPK/ULK1 signaling pathway might be involved in MDMA-induced autophagy activation.

  14. Cell-Type Specific Development of the Hyperpolarization-Activated Current, Ih, in Prefrontal Cortical Neurons

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    Sha-Sha Yang

    2018-05-01

    Full Text Available H-current, also known as hyperpolarization-activated current (Ih, is an inward current generated by the hyperpolarization-activated cyclic nucleotide-gated (HCN cation channels. Ih plays an essential role in regulating neuronal properties, synaptic integration and plasticity, and synchronous activity in the brain. As these biological factors change across development, the brain undergoes varying levels of vulnerability to disorders like schizophrenia that disrupt prefrontal cortex (PFC-dependent function. However, developmental changes in Ih in PFC neurons remains untested. Here, we examine Ih in pyramidal neurons vs. gamma-aminobutyric acid (GABAergic parvalbumin-expressing (PV+ interneurons in developing mouse PFC. Our findings show that the amplitudes of Ih in these cell types are identical during the juvenile period but differ at later time points. In pyramidal neurons, Ih amplitude significantly increases from juvenile to adolescence and follows a similar trend into adulthood. In contrast, the amplitude of Ih in PV+ interneurons decreases from juvenile to adolescence, and does not change from adolescence to adulthood. Moreover, the kinetics of HCN channels in pyramidal neurons is significantly slower than in PV+ interneurons, with a gradual decrease in pyramidal neurons and a gradual increase in PV+ cells across development. Our study reveals distinct developmental trajectories of Ih in pyramidal neurons and PV+ interneurons. The cell-type specific alteration of Ih during the critical period from juvenile to adolescence reflects the contribution of Ih to the maturation of the PFC and PFC-dependent function. These findings are essential for a better understanding of normal PFC function, and for elucidating Ih’s crucial role in the pathophysiology of neurodevelopmental disorders.

  15. Elevated left mid-frontal cortical activity prospectively predicts conversion to bipolar I disorder

    Science.gov (United States)

    Nusslock, Robin; Harmon-Jones, Eddie; Alloy, Lauren B.; Urosevic, Snezana; Goldstein, Kim; Abramson, Lyn Y.

    2013-01-01

    Bipolar disorder is characterized by a hypersensitivity to reward-relevant cues and a propensity to experience an excessive increase in approach-related affect, which may be reflected in hypo/manic symptoms. The present study examined the relationship between relative left-frontal electroencephalographic (EEG) activity, a proposed neurophysiological index of approach-system sensitivity and approach/reward-related affect, and bipolar course and state-related variables. Fifty-eight individuals with cyclothymia or bipolar II disorder and 59 healthy control participants with no affective psychopathology completed resting EEG recordings. Alpha power was obtained and asymmetry indices computed for homologous electrodes. Bipolar spectrum participants were classified as being in a major/minor depressive episode, a hypomanic episode, or a euthymic/remitted state at EEG recording. Participants were then followed prospectively for an average 4.7 year follow-up period with diagnostic interview assessments every four-months. Sixteen bipolar spectrum participants converted to bipolar I disorder during follow-up. Consistent with hypotheses, elevated relative left-frontal EEG activity at baseline 1) prospectively predicted a greater likelihood of converting from cyclothymia or bipolar II disorder to bipolar I disorder over the 4.7 year follow-up period, 2) was associated with an earlier age-of-onset of first bipolar spectrum episode, and 3) was significantly elevated in bipolar spectrum individuals in a hypomanic episode at EEG recording. This is the first study to identify a neurophysiological marker that prospectively predicts conversion to bipolar I disorder. The fact that unipolar depression is characterized by decreased relative left-frontal EEG activity suggests that unipolar depression and vulnerability to hypo/mania may be characterized by different profiles of frontal EEG asymmetry. PMID:22775582

  16. On-going collaborative priority-setting for research activity: a method of capacity building to reduce the research-practice translational gap.

    Science.gov (United States)

    Cooke, Jo; Ariss, Steven; Smith, Christine; Read, Jennifer

    2015-05-07

    International policy suggests that collaborative priority setting (CPS) between researchers and end users of research should shape the research agenda, and can increase capacity to address the research-practice translational gap. There is limited research evidence to guide how this should be done to meet the needs of dynamic healthcare systems. One-off priority setting events and time-lag between decision and action prove problematic. This study illustrates the use of CPS in a UK research collaboration called Collaboration and Leadership in Applied Health Research and Care (CLAHRC). Data were collected from a north of England CLAHRC through semi-structured interviews with 28 interviewees and a workshop of key stakeholders (n = 21) including academics, NHS clinicians, and managers. Documentary analysis of internal reports and CLAHRC annual reports for the first two and half years was also undertaken. These data were thematically coded. Methods of CPS linked to the developmental phase of the CLAHRC. Early methods included pre-existing historical partnerships with on-going dialogue. Later, new platforms for on-going discussions were formed. Consensus techniques with staged project development were also used. All methods demonstrated actual or potential change in practice and services. Impact was enabled through the flexibility of research and implementation work streams; 'matched' funding arrangements to support alignment of priorities in partner organisations; the size of the collaboration offering a resource to meet project needs; and the length of the programme providing stability and long term relationships. Difficulties included tensions between being responsive to priorities and the possibility of 'drift' within project work, between academics and practice, and between service providers and commissioners in the health services. Providing protected 'matched' time proved difficult for some NHS managers, which put increasing work pressure on them. CPS is more time

  17. Relationship between saccadic eye movements and cortical activity as measured by fMRI

    DEFF Research Database (Denmark)

    Kimmig, H.; Greenlee, M.W.; Gondan, Matthias

    2001-01-01

    comprised the frontal and supplementary eye fields, parietal as well as striate cortex, and the motion sensitive area of the parieto-occipital cortex. All these regions showed saccade-related BOLD responses. The responses in these regions were highly correlated with saccade frequency, indicating...... comparing provs anti-saccades we found higher BOLD activation in the "anti" task than in the "pro" task. A comparison of saccade parameters revealed that saccade frequency and cumulative amplitude were comparable between the two tasks, whereas reaction times were longer in the "anti" task than the pro task...

  18. Effects of prefrontal cortical inactivation on neural activity in the ventral tegmental area

    Science.gov (United States)

    Jo, Yong Sang; Lee, Jane; Mizumori, Sheri J.Y.

    2013-01-01

    Dopamine (DA) cells have been suggested to signal discrepancies between expected and actual rewards in reinforcement learning. DA cells in the ventral tegmental area (VTA) receive direct projections from the medial prefrontal cortex (mPFC), a structure that is known as one of the brain areas that represent expected future rewards. To investigate whether the mPFC contributes to generating reward prediction error signals of DA cells, we recorded VTA cells from rats foraging for different amounts of reward in a spatial working memory task. Our results showed that DA cells initially responded after the acquisition of rewards, but over training, they exhibited phasic responses when rats detected sensory cues originating from the rewards before obtaining them. We also observed two separate groups of non-DA cells that were activated in expectation of upcoming rewards or during reward consumption. Bilateral injections of muscimol, a GABAA agonist, into the mPFC significantly decreased the non-DA activity that encoded reward expectation. By contrast, the same manipulation of the mPFC elevated DA responses to reward-predicting cues. However, neither DA nor non-DA responses that were elicited after reward acquisition were affected by mPFC inactivation. These results suggest that the mPFC provides the information about expected rewards to the VTA, and its functional loss elevates DA responses to reward-predicting cues by altering expectations about forthcoming rewards. PMID:23658156

  19. Pain Modulation in Waking and Hypnosis in Women: Event-Related Potentials and Sources of Cortical Activity

    Science.gov (United States)

    De Pascalis, Vilfredo; Varriale, Vincenzo; Cacace, Immacolata

    2015-01-01

    Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs) whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs) during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA) method revealed significant activations of the bilateral primary somatosensory (BA3), middle frontal gyrus (BA6) and anterior cingulate cortices (BA24). Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32), while for the P200 wave, activity was increased in the superior (BA22), middle (BA37), inferior temporal (BA19) gyri and superior parietal lobule (BA7). Hypnotic hypoalgesia in HHs, for N

  20. Pain modulation in waking and hypnosis in women: event-related potentials and sources of cortical activity.

    Directory of Open Access Journals (Sweden)

    Vilfredo De Pascalis

    Full Text Available Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA method revealed significant activations of the bilateral primary somatosensory (BA3, middle frontal gyrus (BA6 and anterior cingulate cortices (BA24. Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32, while for the P200 wave, activity was increased in the superior (BA22, middle (BA37, inferior temporal (BA19 gyri and superior parietal lobule (BA7. Hypnotic hypoalgesia in

  1. Modulation of medial prefrontal cortical activity using in vivo recordings and optogenetics

    Directory of Open Access Journals (Sweden)

    Ji Guangchen

    2012-10-01

    Full Text Available Abstract Background The medial prefrontal cortex (mPFC serves major executive functions. mPFC output to subcortical brain areas such as the amygdala controls emotional processing and plays an important role in fear extinction. Impaired mPFC function correlates with extinction deficits in anxiety disorders such as PTSD and with cognitive decision-making deficits in neuropsychiatric disorders and persistent pain. Controlling mPFC output is a desirable therapeutic goal in neuropsychiatric disorders but functional differences of cell types (pyramidal cells and interneurons and regions (infralimbic and prelimbic represent a challenge. This electrophysiological study used optogenetics for the cell- and region-specific modulation of mPFC pyramidal output in the intact anesthetized animal. Results Extracellular single-unit recordings were made from infralimbic (IL pyramidal cells, IL interneurons and prelimbic (PL pyramidal cells 2–3 weeks after intra-IL injection of a viral vector encoding channel rhodopsin 2 (ChR2 under the control of the CaMKII promoter (rAAV5/CaMKIIa-ChR2(H134R-EYFP or a control vector that lacked the ChR2 sequence (rAAV5/CaMKIIa-EYFP. Optical stimulation with laser-generated blue light pulses delivered through an optical fiber to the IL increased spontaneous and evoked action potential firing of ChR2 expressing IL pyramidal cells but had no effect on IL interneurons that were distinguished from pyramidal cells based on their higher firing rate and shorter spike duration. Optical activation of IL pyramidal cells also inhibited PL pyramidal cells, suggesting that IL output controls PL output. The effects were light intensity-dependent and reversible. Confocal microscopy confirmed ChR2-EYFP or control vector expression in mPFC pyramidal cells but not in GABAergic cells. Conclusions The novelty of our study is the analysis of optogenetic effects on background and evoked activity of defined cell types in different mPFC regions. The

  2. Effects of activated ACM on expression of signal transducers in cerebral cortical neurons of rats.

    Science.gov (United States)

    Wang, Xiaojing; Li, Zhengli; Zhu, Changgeng; Li, Zhongyu

    2007-06-01

    To explore the roles of astrocytes in the epileptogenesis, astrocytes and neurons were isolated, purified and cultured in vitro from cerebral cortex of rats. The astrocytes were activated by ciliary neurotrophic factor (CNTF) and astrocytic conditioned medium (ACM) was collected to treat neurons for 4, 8 and 12 h. By using Western blot, the expression of calmodulin dependent protein kinase II (CaMK II), inducible nitric oxide synthase (iNOS) and adenylate cyclase (AC) was detected in neurons. The results showed that the expression of CaMK II, iNOS and AC was increased significantly in the neurons treated with ACM from 4 h to 12 h (PACM and such signal pathways as NOS-NO-cGMP, Ca2+/CaM-CaMK II and AC-cAMP-PKA might take part in the signal transduction of epileptogenesis.

  3. Why Does Sleep Slow-Wave Activity Increase After Extended Wake? Assessing the Effects of Increased Cortical Firing During Wake and Sleep.

    Science.gov (United States)

    Rodriguez, Alexander V; Funk, Chadd M; Vyazovskiy, Vladyslav V; Nir, Yuval; Tononi, Giulio; Cirelli, Chiara

    2016-12-07

    During non-rapid eye movement (NREM) sleep, cortical neurons alternate between ON periods of firing and OFF periods of silence. This bi-stability, which is largely synchronous across neurons, is reflected in the EEG as slow waves. Slow-wave activity (SWA) increases with wake duration and declines homeostatically during sleep, but the underlying mechanisms remain unclear. One possibility is neuronal "fatigue": high, sustained firing in wake would force neurons to recover with more frequent and longer OFF periods during sleep. Another possibility is net synaptic potentiation during wake: stronger coupling among neurons would lead to greater synchrony and therefore higher SWA. Here, we obtained a comparable increase in sustained firing (6 h) in cortex by: (1) keeping mice awake by exposure to novel objects to promote plasticity and (2) optogenetically activating a local population of cortical neurons at wake-like levels during sleep. Sleep after extended wake led to increased SWA, higher synchrony, and more time spent OFF, with a positive correlation between SWA, synchrony, and OFF periods. Moreover, time spent OFF was correlated with cortical firing during prior wake. After local optogenetic stimulation, SWA and cortical synchrony decreased locally, time spent OFF did not change, and local SWA was not correlated with either measure. Moreover, laser-induced cortical firing was not correlated with time spent OFF afterward. Overall, these results suggest that high sustained firing per se may not be the primary determinant of SWA increases observed after extended wake. A long-standing hypothesis is that neurons fire less during slow-wave sleep to recover from the "fatigue" accrued during wake, when overall synaptic activity is higher than in sleep. This idea, however, has rarely been tested and other factors, namely increased cortical synchrony, could explain why sleep slow-wave activity (SWA) is higher after extended wake. We forced neurons in the mouse cortex to fire

  4. Effects of an environmentally-relevant mixture of pyrethroid insecticides on spontaneous activity in primary cortical networks on microelectrode arrays.

    Science.gov (United States)

    Johnstone, Andrew F M; Strickland, Jenna D; Crofton, Kevin M; Gennings, Chris; Shafer, Timothy J

    2017-05-01

    Pyrethroid insecticides exert their insecticidal and toxicological effects primarily by disrupting voltage-gated sodium channel (VGSC) function, resulting in altered neuronal excitability. Numerous studies of individual pyrethroids have characterized effects on mammalian VGSC function and neuronal excitability, yet studies examining effects of complex pyrethroid mixtures in mammalian neurons, especially in environmentally relevant mixture ratios, are limited. In the present study, concentration-response functions were characterized for five pyrethroids (permethrin, deltamethrin, cypermethrin, β-cyfluthrin and esfenvalerate) in an in vitro preparation containing cortical neurons and glia. As a metric of neuronal network activity, spontaneous mean network firing rates (MFR) were measured using microelectorde arrays (MEAs). In addition, the effect of a complex and exposure relevant mixture of the five pyrethroids (containing 52% permethrin, 28.8% cypermethrin, 12.9% β-cyfluthrin, 3.4% deltamethrin and 2.7% esfenvalerate) was also measured. Data were modeled to determine whether effects of the pyrethroid mixture were predicted by dose-addition. At concentrations up to 10μM, all compounds except permethrin reduced MFR. Deltamethrin and β-cyfluthrin were the most potent and reduced MFR by as much as 60 and 50%, respectively, while cypermethrin and esfenvalerate were of approximately equal potency and reduced MFR by only ∼20% at the highest concentration. Permethrin caused small (∼24% maximum), concentration-dependent increases in MFR. Effects of the environmentally relevant mixture did not depart from the prediction of dose-addition. These data demonstrate that an environmentally relevant mixture caused dose-additive effects on spontaneous neuronal network activity in vitro, and is consistent with other in vitro and in vivo assessments of pyrethroid mixtures. Published by Elsevier B.V.

  5. Patterns of cortical oscillations organize neural activity into whole-brain functional networks evident in the fMRI BOLD signal

    Directory of Open Access Journals (Sweden)

    Jennifer C Whitman

    2013-03-01

    Full Text Available Recent findings from electrophysiology and multimodal neuroimaging have elucidated the relationship between patterns of cortical oscillations evident in EEG / MEG and the functional brain networks evident in the BOLD signal. Much of the existing literature emphasized how high-frequency cortical oscillations are thought to coordinate neural activity locally, while low-frequency oscillations play a role in coordinating activity between more distant brain regions. However, the assignment of different frequencies to different spatial scales is an oversimplification. A more informative approach is to explore the arrangements by which these low- and high-frequency oscillations work in concert, coordinating neural activity into whole-brain functional networks. When relating such networks to the BOLD signal, we must consider how the patterns of cortical oscillations change at the same speed as cognitive states, which often last less than a second. Consequently, the slower BOLD signal may often reflect the summed neural activity of several transient network configurations. This temporal mismatch can be circumvented if we use spatial maps to assess correspondence between oscillatory networks and BOLD networks.

  6. Word wins over Face: Emotional Stroop effect activates the frontal cortical network

    Directory of Open Access Journals (Sweden)

    Shima Ovaysikia

    2011-01-01

    Full Text Available The prefrontal cortex (PFC has been implicated in higher order cognitive control of behaviour. Sometimes such control is executed through suppression of an unwanted response in order to avoid conflict. Conflict occurs when two simultaneously competing processes lead to different behavioral outcomes, as seen in tasks such as the anti-saccade, go/no-go and the Stroop task. We set out to examine whether different types of stimuli in a modified emotional Stroop task would cause similar interference effects as the original Stroop-colour/word, and whether the required suppression mechanism(s would recruit similar regions of the medial PFC (mPFC. By using emotional words and emotional faces in this Stroop experiment, we examined the two well-learned automatic behaviours of word reading and recognition of face expressions. In our emotional Stroop paradigm, words were processed faster than face expressions with incongruent trials yielding longer reaction times (RT and larger number of errors compared to the congruent trials. This novel Stroop effect activated the anterior and inferior regions of the mPFC, namely the anterior cingulate cortex (ACC, inferior frontal gyrus (IFG as well as the superior frontal gyrus. Our results suggest that prepotent behaviours such as reading and recognition of face expressions are stimulus-dependent and perhaps hierarchical, hence recruiting distinct regions of the mPFC. Moreover, the faster processing of word reading compared to reporting face expressions is indicative of the formation of stronger stimulus-response (SR associations of an over-learned behaviour compared to an instinctive one, which could alternatively be explained through the distinction between awareness and selective attention.

  7. Co-emergence of multi-scale cortical activities of irregular firing, oscillations and avalanches achieves cost-efficient information capacity.

    Directory of Open Access Journals (Sweden)

    Dong-Ping Yang

    2017-02-01

    Full Text Available The brain is highly energy consuming, therefore is under strong selective pressure to achieve cost-efficiency in both cortical connectivities and activities. However, cost-efficiency as a design principle for cortical activities has been rarely studied. Especially it is not clear how cost-efficiency is related to ubiquitously observed multi-scale properties: irregular firing, oscillations and neuronal avalanches. Here we demonstrate that these prominent properties can be simultaneously observed in a generic, biologically plausible neural circuit model that captures excitation-inhibition balance and realistic dynamics of synaptic conductance. Their co-emergence achieves minimal energy cost as well as maximal energy efficiency on information capacity, when neuronal firing are coordinated and shaped by moderate synchrony to reduce otherwise redundant spikes, and the dynamical clusterings are maintained in the form of neuronal avalanches. Such cost-efficient neural dynamics can be employed as a foundation for further efficient information processing under energy constraint.

  8. Alterations in visual cortical activation and connectivity with prefrontal cortex during working memory updating in major depressive disorder.

    Science.gov (United States)

    Le, Thang M; Borghi, John A; Kujawa, Autumn J; Klein, Daniel N; Leung, Hoi-Chung

    2017-01-01

    The present study examined the impacts of major depressive disorder (MDD) on visual and prefrontal cortical activity as well as their connectivity during visual working memory updating and related them to the core clinical features of the disorder. Impairment in working memory updating is typically associated with the retention of irrelevant negative information which can lead to persistent depressive mood and abnormal affect. However, performance deficits have been observed in MDD on tasks involving little or no demand on emotion processing, suggesting dysfunctions may also occur at the more basic level of information processing. Yet, it is unclear how various regions in the visual working memory circuit contribute to behavioral changes in MDD. We acquired functional magnetic resonance imaging data from 18 unmedicated participants with MDD and 21 age-matched healthy controls (CTL) while they performed a visual delayed recognition task with neutral faces and scenes as task stimuli. Selective working memory updating was manipulated by inserting a cue in the delay period to indicate which one or both of the two memorized stimuli (a face and a scene) would remain relevant for the recognition test. Our results revealed several key findings. Relative to the CTL group, the MDD group showed weaker postcue activations in visual association areas during selective maintenance of face and scene working memory. Across the MDD subjects, greater rumination and depressive symptoms were associated with more persistent activation and connectivity related to no-longer-relevant task information. Classification of postcue spatial activation patterns of the scene-related areas was also less consistent in the MDD subjects compared to the healthy controls. Such abnormalities appeared to result from a lack of updating effects in postcue functional connectivity between prefrontal and scene-related areas in the MDD group. In sum, disrupted working memory updating in MDD was revealed by

  9. Activity measurements of the radionuclide {sup 124}Sb by the LNE-LNHB, France for the ongoing comparison BIPM.RI(II)-K1.Sb-124

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, F-92312 Sevres Cedex, (France); Moune, M.; Bobin, C. [Laboratoire national de metrologie et d' essais-Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex, (France)

    2011-07-01

    In 2007, the Laboratoire national de metrologie et d'essais-Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 124}Sb to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). The activity was about 5.3 MBq. The key comparison reference value (KCRV) has been recalculated to include this new value and the degrees of equivalence between each equivalent activity for the three participants measured in the SIR and the KCRV are presented in a table and graphically. (authors)

  10. Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks.

    Science.gov (United States)

    DeMarse, Thomas B; Pan, Liangbin; Alagapan, Sankaraleengam; Brewer, Gregory J; Wheeler, Bruce C

    2016-01-01

    Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura's and van Rossum's spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous synchronized

  11. Activity measurements of the radionuclide {sup 111}In for the LNE-LNHB, France in the ongoing comparison BIPM.RI(II)-K1.In-111

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Ratel, G.; Courte, S. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, 92 - Sevres (France); Verdeau, E.; Amiot, M.N. [Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France)

    2010-10-15

    In 2006, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB) submitted a sample of known activity of {sup 111}In to the International Reference System (SIR). The value of the activity submitted was about 14 MBq. This provides a new result for France in the matrix of degrees of equivalence in the key comparison database that enables them to maintain their degrees of equivalence for this radionuclide. The key comparison reference value has been re-evaluated and the comparison, identifier BIPM.RI(II)-K1.In-111, now contains five valid results. (authors)

  12. Cortical gamma activity during auditory tone omission provides evidence for the involvement of oscillatory activity in top-down processing.

    Science.gov (United States)

    Gurtubay, I G; Alegre, M; Valencia, M; Artieda, J

    2006-11-01

    Perception is an active process in which our brains use top-down influences to modulate afferent information. To determine whether this modulation might be based on oscillatory activity, we asked seven subjects to detect a silence that appeared randomly in a rhythmic auditory sequence, counting the number of omissions ("count" task), or responding to each omission with a right index finger extension ("move" task). Despite the absence of physical stimuli, these tasks induced a 'non-phase-locked' gamma oscillation in temporal-parietal areas, providing evidence of intrinsically generated oscillatory activity during top-down processing. This oscillation is probably related to the local neural activation that takes place during the process of stimulus detection, involving the functional comparison between the tones and the absence of stimuli as well as the auditory echoic memory processes. The amplitude of the gamma oscillations was reduced with the repetition of the tasks. Moreover, it correlated positively with the number of correctly detected omissions and negatively with the reaction time. These findings indicate that these oscillations, like others described, may be modulated by attentional processes. In summary, our findings support the active and adaptive concept of brain function that has emerged over recent years, suggesting that the match of sensory information with memory contents generates gamma oscillations.

  13. Successful declarative memory formation is associated with ongoing activity during encoding in a distributed neocortical network related to working memory: a magnetoencephalography study.

    NARCIS (Netherlands)

    Takashima, A.; Jensen, O.; Oostenveld, R.; Maris, E.G.G.; Coevering, M. van de; Fernandez, G.S.E.

    2006-01-01

    The aim of the present study was to investigate the spatio-temporal characteristics of the neural correlates of declarative memory formation as assessed by the subsequent memory effect, i.e. the difference in encoding activity between subsequently remembered and subsequently forgotten items.

  14. Successful declarative memory formation is associated with ongoing activity during encoding in a distributed neocortical network related to working memory: A magnetoencephalography study

    NARCIS (Netherlands)

    Takashima, A.; Jensen, O.; Oostenveld, R.; Maris, E.G.G.; Coevering, M. van de; Fernandez, G.S.E.

    2006-01-01

    The aim of the present study was to investigate the spatio-temporal characteristics of the neural correlates of declarative memory formation as assessed by the subsequent memory effect, i.e. the difference in encoding activity between subsequently remembered and subsequently forgotten items.

  15. Endogenous Cortical Oscillations Constrain Neuromodulation by Weak Electric Fields

    Science.gov (United States)

    Schmidt, Stephen L.; Iyengar, Apoorva K.; Foulser, A. Alban; Boyle, Michael R.; Fröhlich, Flavio

    2014-01-01

    Background Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation modality that may modulate cognition by enhancing endogenous neocortical oscillations with the application of sine-wave electric fields. Yet, the role of endogenous network activity in enabling and shaping the effects of tACS has remained unclear. Objective We combined optogenetic stimulation and multichannel slice electrophysiology to elucidate how the effect of weak sine-wave electric field depends on the ongoing cortical oscillatory activity. We hypothesized that the structure of the response to stimulation depended on matching the stimulation frequency to the endogenous cortical oscillation. Methods We studied the effect of weak sine-wave electric fields on oscillatory activity in mouse neocortical slices. Optogenetic control of the network activity enabled the generation of in vivo like cortical oscillations for studying the temporal relationship between network activity and sine-wave electric field stimulation. Results Weak electric fields enhanced endogenous oscillations but failed to induce a frequency shift of the ongoing oscillation for stimulation frequencies that were not matched to the endogenous oscillation. This constraint on the effect of electric field stimulation imposed by endogenous network dynamics was limited to the case of weak electric fields targeting in vivo-like network dynamics. Together, these results suggest that the key mechanism of tACS may be enhancing but not overriding of intrinsic network dynamics. Conclusion Our results contribute to understanding the inconsistent tACS results from human studies and propose that stimulation precisely adjusted in frequency to the endogenous oscillations is key to rational design of non-invasive brain stimulation paradigms. PMID:25129402

  16. Positron emission tomography studies of neuronal activity patterns during sensory and cognitive stimulations in Alzheimer's disease. A study of cortical attention sites in man

    International Nuclear Information System (INIS)

    Johannsen, Peter

    1997-01-01

    This Ph.D.-thesis describes different subtypes of attention, models for the organization of attention, and the attention deficits in Alzheimer's disease. The experimental part of the study is based on studies of sustained and divided attention to two different sensory modalities; a visual checkerboard stimulation reversing at 7 Hz, and a 110 Hz vibrotactile stimulation of the right hand in a group of healthy elderly subjects (n = 16) age-matched with a group of patients with mild to moderate Alzheimer's disease (n = 16). The cortical activations during the attention tasks have been mapped using O-15-water and positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) during rest and during performance of an attention task. After anatomical standardization and averaging over subjects, activation foci were assessed by a t-statistical evaluation of the differences of rCBF maps acquired before and during the execution of the attention tasks. The rCBF deficits in the Alzheimer patients were compared to rCBF pattern in the healthy elderly and assessed statistically on a voxel-by-voxel basis, revealing a distinct and localized pattern of rCBF deficits extending from the hippocampal area along the longitudinal fascicle to the temporo-parietal cortices with further deficits in the frontal regions. The resting rCBF deficits are distributed with the same pattern as described in neuropathological studies of lesions in Alzheimer's disease. In the healthy elderly, both sustained and divided attention elicited activation of the right inferior parietal lobule (Brodmann Area 19/40) and the right middle frontal gyrus (Brodmann Area 46). Divided attention favored activation of the right middle frontal gyrus and sustained attention activation of the right inferior parietal lobule. Both the frontal and the parietal attention sites were active during attention to both the visual and the vibrotactile stimuli. These results support a network hypothesis of

  17. Positron emission tomography studies of neuronal activity patterns during sensory and cognitive stimulations in Alzheimer`s disease. A study of cortical attention sites in man

    Energy Technology Data Exchange (ETDEWEB)

    Johannsen, Peter

    1997-12-31

    This Ph.D.-thesis describes different subtypes of attention, models for the organization of attention, and the attention deficits in Alzheimer`s disease. The experimental part of the study is based on studies of sustained and divided attention to two different sensory modalities; a visual checkerboard stimulation reversing at 7 Hz, and a 110 Hz vibrotactile stimulation of the right hand in a group of healthy elderly subjects (n = 16) age-matched with a group of patients with mild to moderate Alzheimer`s disease (n = 16). The cortical activations during the attention tasks have been mapped using O-15-water and positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) during rest and during performance of an attention task. After anatomical standardization and averaging over subjects, activation foci were assessed by a t-statistical evaluation of the differences of rCBF maps acquired before and during the execution of the attention tasks. The rCBF deficits in the Alzheimer patients were compared to rCBF pattern in the healthy elderly and assessed statistically on a voxel-by-voxel basis, revealing a distinct and localized pattern of rCBF deficits extending from the hippocampal area along the longitudinal fascicle to the temporo-parietal cortices with further deficits in the frontal regions. The resting rCBF deficits are distributed with the same pattern as described in neuropathological studies of lesions in Alzheimer`s disease. In the healthy elderly, both sustained and divided attention elicited activation of the right inferior parietal lobule (Brodmann Area 19/40) and the right middle frontal gyrus (Brodmann Area 46). Divided attention favored activation of the right middle frontal gyrus and sustained attention activation of the right inferior parietal lobule. Both the frontal and the parietal attention sites were active during attention to both the visual and the vibrotactile stimuli. These results support a network hypothesis of

  18. Activity measurements of the radionuclide 109Cd for the PTB, Germany and the NIST, USA in the ongoing comparison BIPM.RI(II)-K1.Cd-109

    International Nuclear Information System (INIS)

    Ratel, G.; Michotte, C.; Janssen, H.; Kossert, K.; Lucas, L.; Karam, L.

    2005-01-01

    In 2004, the Physikalisch-Technische Bundesanstalt (PTB, Germany) and the National Institute of Standards and Technology (NIST, USA) each submitted one sample of known activity of 109 Cd to the International Reference System (SIR). The PTB result replaces their previous measurement of 1994 and the NIST result updates their 1986 CCRI(II) comparison result. The values of the activity submitted were about 15 MBq and 42 MBq. The new key comparison results have replaced the earlier values in the matrix of degrees of equivalence that now contains six results, identifier BIPM.RI(II)-K1.Cd-109, to which the remaining eleven results from the CCRI(II)-K2.Cd-109 held in 1986 are still linked. (authors)

  19. Ongoing Space Physics - Astrophysics Connections

    OpenAIRE

    Eichler, David

    2005-01-01

    I review several ongoing connections between space physics and astrophysics: a) Measurements of energetic particle spectra have confirmed theoretical prediction of the highest energy to which shocks can accelerate particles, and this has direct bearing on the origin of the highest energy cosmic rays. b) Mass ejection in solar flares may help us understand photon ejection in the giant flares of magnetar outbursts. c) Measurements of electron heat fluxes in the solar wind can help us understand...

  20. Dense neuron clustering explains connectivity statistics in cortical microcircuits.

    Directory of Open Access Journals (Sweden)

    Vladimir V Klinshov

    Full Text Available Local cortical circuits appear highly non-random, but the underlying connectivity rule remains elusive. Here, we analyze experimental data observed in layer 5 of rat neocortex and suggest a model for connectivity from which emerge essential observed non-random features of both wiring and weighting. These features include lognormal distributions of synaptic connection strength, anatomical clustering, and strong correlations between clustering and connection strength. Our model predicts that cortical microcircuits contain large groups of densely connected neurons which we call clusters. We show that such a cluster contains about one fifth of all excitatory neurons of a circuit which are very densely connected with stronger than average synapses. We demonstrate that such clustering plays an important role in the network dynamics, namely, it creates bistable neural spiking in small cortical circuits. Furthermore, introducing local clustering in large-scale networks leads to the emergence of various patterns of persistent local activity in an ongoing network activity. Thus, our results may bridge a gap between anatomical structure and persistent activity observed during working memory and other cognitive processes.

  1. Lack of on-going adaptations in the soleus muscle activity during walking in patients affected by large-fiber neuropathy

    DEFF Research Database (Denmark)

    Nazarena, Mazzaro; Grey, Michael James; Sinkjær, Thomas

    2005-01-01

    The aim of this study was to investigate the contribution of feedback from large-diameter sensory fibers to the adaptation of soleus muscle activity after small ankle trajectory modifications during human walking. Small-amplitude and slow-velocity ankle dorsiflexion enhancements and reductions were...... applied during the stance phase of the gait cycle to mimic the normal variability of the ankle trajectory during walking. Patients with demyelination of large sensory fibers (Charcot-Marie-Tooth type 1A and antibodies to myelin-associated glycoprotein neuropathy) and age-matched controls participated...... duration (P ankle dorsiflexion was, respectively, enhanced or reduced. In the patients, the soleus EMG increased during the dorsiflexion...

  2. The role of School of Mines in regional and national environmental protection endeavours. An outline of past and on-going project activities

    International Nuclear Information System (INIS)

    Sinkala, T; Simukanga, S.

    2002-01-01

    This paper outlines the contribution of the School of Mines in national and regional environmental protection activities. Projects include those undertaken under the Southern African Network for Training on the environment (SANTREN), Southern African Development Community (SADC), the Ministry of Mines and Mineral Development, and the Ministry of Environment and Natural Resources. Issues include mining and the environment, small scale mining, environmental impact assessments, river systems, water quality, air quality and environmental technologies. The paper is concluded by pointing out the efforts by the School to introduce a Mining and Environment Program in the wake of the need to promote public awareness at tertiary level. (authors)

  3. Development and Preliminary Feasibility Study of a Brief Behavioral Activation Mobile Application (Behavioral Apptivation) to Be Used in Conjunction With Ongoing Therapy.

    Science.gov (United States)

    Dahne, Jennifer; Kustanowitz, Jacob; Lejuez, C W

    2018-02-01

    Depressive symptoms are the most frequently treated psychiatric condition in the United States. Brief behavioral activation treatment for depression (BATD) is a popular, evidence-based psychotherapy with strong research support for the treatment of depression. In this paper, we describe the development and initial pilot feasibility testing of a BATD mobile application (Behavioral Apptivation) to be used by patients and therapists in conjunction with BATD therapy. We present information regarding the app development process as well as results from a small open-label feasibility trial of the app utilized in conjunction with individual BATD. We include a case series from the open-label trial highlighting how Behavioral Apptivation can be utilized in clinical practice.

  4. 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.

  5. Measurement of cortical functional activation in awake mice using two-photon microscopy and a novel pO2-sensitive probe(Conference Presentation)

    Science.gov (United States)

    Sencan, Ikbal; Esipova, Tatiana V.; Kilic, Kivilcim; Li, Baoqiang; Desjardins, Michèle; Yaseen, Mohammad A.; Wang, Hui; Jaswal, Rajeshwer S.; Kura, Sreekanth; Fu, Buyin; Boas, David A.; Devor, Anna; Sakadžić, Sava; Vinogradov, Sergei A.

    2017-02-01

    We characterized cortical microvascular PO2 and blood flow changes in response to whisker stimulation in awake mice. The measurements were performed by combining two-photon microscopy imaging of the cortical oxygenation and optical coherence tomography imaging of the cerebral blood flow. In order to perform fast spatio-temporally resolved measurements of PO2, we used a newly-developed oxygen-sensitive probe PtG-2P, which has significantly higher brightness than the established two-photon-enhanced oxygen sensor PtP-C343. We characterized the performance of the new probe in vivo and mapped the amplitudes and shapes (e.g. initial dip, overshoot, and post stimulus undershoot) of the PO2 changes as a function of the vessel type (e.g., arterioles, capillaries, and venules) and a distance from the activation center. The measurements in the awake mice are not affected by the confounding factors of anesthesia on the animal physiology, including the level of cerebral metabolism and the amplitude and speed of neuronal and vascular responses. Our results will help to understand changes in oxygenation and blood flow on the cortical microvascular scale, will lead to improved understanding of the cerebral physiology, pathophysiology and will improve quantitative interpretation of fMRI signals.

  6. Simultaneous imaging of cerebral partial pressure of oxygen and blood flow during functional activation and cortical spreading depression

    Science.gov (United States)

    Sakadžić, Sava; Yuan, Shuai; Dilekoz, Ergin; Ruvinskaya, Svetlana; Vinogradov, Sergei A.; Ayata, Cenk; Boas, David A.

    2009-01-01

    We developed a novel imaging technique that provides real-time two-dimensional maps of the absolute partial pressure of oxygen and relative cerebral blood flow in rats by combining phosphorescence lifetime imaging with laser speckle contrast imaging. Direct measurement of blood oxygenation based on phosphorescence lifetime is not significantly affected by changes in the optical parameters of the tissue during the experiment. The potential of the system as a novel tool for quantitative analysis of the dynamic delivery of oxygen to support brain metabolism was demonstrated in rats by imaging cortical responses to forepaw stimulation and the propagation of cortical spreading depression waves. This new instrument will enable further study of neurovascular coupling in normal and diseased brain. PMID:19340106

  7. Cortical visual impairment

    OpenAIRE

    Koželj, Urša

    2013-01-01

    In this thesis we discuss cortical visual impairment, diagnosis that is in the developed world in first place, since 20 percent of children with blindness or low vision are diagnosed with it. The objectives of the thesis are to define cortical visual impairment and the definition of characters suggestive of the cortical visual impairment as well as to search for causes that affect the growing diagnosis of cortical visual impairment. There are a lot of signs of cortical visual impairment. ...

  8. Prefrontal cortical and striatal activity to happy and fear faces in bipolar disorder is associated with comorbid substance abuse and eating disorder.

    Science.gov (United States)

    Hassel, Stefanie; Almeida, Jorge R; Frank, Ellen; Versace, Amelia; Nau, Sharon A; Klein, Crystal R; Kupfer, David J; Phillips, Mary L

    2009-11-01

    The spectrum approach was used to examine contributions of comorbid symptom dimensions of substance abuse and eating disorder to abnormal prefrontal-cortical and subcortical-striatal activity to happy and fear faces previously demonstrated in bipolar disorder (BD). Fourteen remitted BD-type I and sixteen healthy individuals viewed neutral, mild and intense happy and fear faces in two event-related fMRI experiments. All individuals completed Substance-Use and Eating-Disorder Spectrum measures. Region-of-Interest analyses for bilateral prefrontal and subcortical-striatal regions were performed. BD individuals scored significantly higher on these spectrum measures than healthy individuals (pright PFC activity to intense happy faces (pright caudate nucleus activity to neutral faces (pright ventral putamen activity to intense happy (pabuse and eating disorder and prefrontal-cortical and subcortical-striatal activity to facial expressions in BD. Our findings suggest that these comorbid features may contribute to observed patterns of functional abnormalities in neural systems underlying mood regulation in BD.

  9. Effects of action observation therapy on hand dexterity and EEG-based cortical activation patterns in patients with post-stroke hemiparesis.

    Science.gov (United States)

    Kuk, Eun-Ju; Kim, Jong-Man; Oh, Duck-Won; Hwang, Han-Jeong

    2016-10-01

    Previous reports have suggested that action observation training (AOT) is beneficial in enhancing the early learning of new motor tasks; however, EEG-based investigation has received little attention for AOT. The purpose of this study was to illustrate the effects of AOT on hand dexterity and cortical activation in patients with post-stroke hemiparesis. Twenty patients with post-stroke hemiparesis were randomly divided into either the experimental group (EG) or control group (CG), with 10 patients in each group. Prior to the execution of motor tasks (carrying wooden blocks from one box to another), subjects in the EG and CG observed a video clip displaying the execution of the same motor task and pictures showing landscapes, respectively. Outcome measures included the box and block test (BBT) to evaluate hand dexterity and EEG-based brain mapping to detect changes in cortical activation. The BBT scores (EG: 20.50 ± 6.62 at pre-test and 24.40 ± 5.42 at post-test; CG: 20.20 ± 6.12 at pre-test and 20.60 ± 7.17 at post-test) revealed significant main effects for the time and group and significant time-by-group interactions (p < 0.05). For the subjects in the EG, topographical representations obtained with the EEG-based brain mapping system were different in each session of the AOT and remarkable changes occurred from the 2nd session of AOT. Furthermore, the middle frontal gyrus was less active at post-test than at pre-test. These findings support that AOT may be beneficial in altering cortical activation patterns and hand dexterity.

  10. Combined DTI Tractography and Functional MRI Study of the Language Connectome in Healthy Volunteers: Extensive Mapping of White Matter Fascicles and Cortical Activations.

    Directory of Open Access Journals (Sweden)

    François Vassal

    Full Text Available Despite a better understanding of brain language organization into large-scale cortical networks, the underlying white matter (WM connectivity is still not mastered. Here we combined diffusion tensor imaging (DTI fiber tracking (FT and language functional magnetic resonance imaging (fMRI in twenty healthy subjects to gain new insights into the macroscopic structural connectivity of language. Eight putative WM fascicles for language were probed using a deterministic DTI-FT technique: the arcuate fascicle (AF, superior longitudinal fascicle (SLF, uncinate fascicle (UF, temporo-occipital fascicle, inferior fronto-occipital fascicle (IFOF, middle longitudinal fascicle (MdLF, frontal aslant fascicle and operculopremotor fascicle. Specific measurements (i.e. volume, length, fractional anisotropy and precise cortical terminations were derived for each WM fascicle within both hemispheres. Connections between these WM fascicles and fMRI activations were studied to determine which WM fascicles are related to language. WM fascicle volumes showed asymmetries: leftward for the AF, temporoparietal segment of SLF and UF, and rightward for the frontoparietal segment of the SLF. The lateralization of the AF, IFOF and MdLF extended to differences in patterns of anatomical connections, which may relate to specific hemispheric abilities. The leftward asymmetry of the AF was correlated to the leftward asymmetry of fMRI activations, suggesting that the lateralization of the AF is a structural substrate of hemispheric language dominance. We found consistent connections between fMRI activations and terminations of the eight WM fascicles, providing a detailed description of the language connectome. WM fascicle terminations were also observed beyond fMRI-confirmed language areas and reached numerous cortical areas involved in different functional brain networks. These findings suggest that the reported WM fascicles are not exclusively involved in language and might be

  11. Combined DTI Tractography and Functional MRI Study of the Language Connectome in Healthy Volunteers: Extensive Mapping of White Matter Fascicles and Cortical Activations.

    Science.gov (United States)

    Vassal, François; Schneider, Fabien; Boutet, Claire; Jean, Betty; Sontheimer, Anna; Lemaire, Jean-Jacques

    2016-01-01

    Despite a better understanding of brain language organization into large-scale cortical networks, the underlying white matter (WM) connectivity is still not mastered. Here we combined diffusion tensor imaging (DTI) fiber tracking (FT) and language functional magnetic resonance imaging (fMRI) in twenty healthy subjects to gain new insights into the macroscopic structural connectivity of language. Eight putative WM fascicles for language were probed using a deterministic DTI-FT technique: the arcuate fascicle (AF), superior longitudinal fascicle (SLF), uncinate fascicle (UF), temporo-occipital fascicle, inferior fronto-occipital fascicle (IFOF), middle longitudinal fascicle (MdLF), frontal aslant fascicle and operculopremotor fascicle. Specific measurements (i.e. volume, length, fractional anisotropy) and precise cortical terminations were derived for each WM fascicle within both hemispheres. Connections between these WM fascicles and fMRI activations were studied to determine which WM fascicles are related to language. WM fascicle volumes showed asymmetries: leftward for the AF, temporoparietal segment of SLF and UF, and rightward for the frontoparietal segment of the SLF. The lateralization of the AF, IFOF and MdLF extended to differences in patterns of anatomical connections, which may relate to specific hemispheric abilities. The leftward asymmetry of the AF was correlated to the leftward asymmetry of fMRI activations, suggesting that the lateralization of the AF is a structural substrate of hemispheric language dominance. We found consistent connections between fMRI activations and terminations of the eight WM fascicles, providing a detailed description of the language connectome. WM fascicle terminations were also observed beyond fMRI-confirmed language areas and reached numerous cortical areas involved in different functional brain networks. These findings suggest that the reported WM fascicles are not exclusively involved in language and might be related to

  12. Instrumental neutron-activation analysis applications in the age dynamics assessment of Ca, Cl, K, Mg. Mn, Na, P, and Sr contents in the human cortical bone

    International Nuclear Information System (INIS)

    Zaichick, V.

    2003-01-01

    Full text: Senile osteoporosis and particularly osteoporosis among postmenopausal women represents an urgent problem of modern medicine. One of the main osteoporosis symptoms is a decrease in both bone mineral density and subsequent bone strength. The upper extremity of the femur in humans is a particularly vulnerable section of the skeleton, being subject to fracture and necrosis and to destruction of its cartilage. Iliac crest biopsies are commonly taken clinically on patients. It is known that the control of the mineral component providing bone strength is a good indicator to detect bone diseases like osteoporosis. Despite this, changes of chemical element contents occurring with age in the femoral head and the iliac crest of female and male separately have been little studied, but in iliac cortical bone have not been studied at all. The effect of age and sex on chemical element contents in intact cortical bone of femoral neck and iliac crest of 81 relatively healthy 15-55 years old women (n=36) and men (n=45) was investigated. All subjects had died suddenly and bone samples were obtained at necropsy from the right side of bodies within twenty-four hours after death. A tool made of titanium and plastic was used to clear samples from soft tissues and blood and to cut cortical part of bone. The IAEA and NIST reference materials (H-5 animal bone and SRM1486 bone meal) were used to estimate the precision and accuracy of results. Contents of Ca, Cl, K, Mg> Mn, Na, P, and Sr in intact bone samples were determined by instrumental neutron activation analysis using short-lived radionuclides. Our means data for each element of reference materials were within the certified 95 % confidence interval, and indicate an acceptable accuracy of the obtained results. No age- and sex-related differences in the cortical femoral neck composition were detected. Mean values (M±S.E.M.) of Ca, Cl, K, Mg, Mn, Na, P, and Sr mass fractions (on dry weight basis) for female and male all

  13. Geomorphological features of active tectonics and ongoing ...

    Indian Academy of Sciences (India)

    earthquakes (magnitude 1.0–3.0) frequently occur in the region and hypocenters of these earthquakes are ... movement of Indian landmass and its collision with ... within the Eurasian Plate (Avouac and Tapponnier .... Description of ... (a) Terrace deposition in Dharchula (India) and Darchula (Nepal) side; (b) series of three ...

  14. Ongoing Projects on Serious Games

    Directory of Open Access Journals (Sweden)

    Carlos Vaz de Carvalho

    2014-08-01

    Full Text Available This number of the EAI Transactions on Serious Games is dedicated to a set of ongoing research and development projects in this area. The selected articles represent very well the diversity of approaches, contexts and objectives that foster and render highly dynamic this area of study. In Europe, several funding programmes like the 7th Framework Programme, the Lifelong Learning Programme and the most recent Horizon 2020 made specific provisions to support Serious Games projects. At the same time, enterprises are recognizing more and more the potential of SG to train and to motivate their workforce and are therefore joining forces with the academy and SG producers to design specific SG. Serious Games became one of the most interesting “places to be” due to its growing scientific and practitioner community. We can say that the motivating and addictive character of games has been successfully transmitted to the research and development of Serious Games.

  15. Nonlinear Recurrent Dynamics and Long-Term Nonstationarities in EEG Alpha Cortical Activity: Implications for Choosing Adequate Segment Length in Nonlinear EEG Analyses.

    Science.gov (United States)

    Cerquera, Alexander; Vollebregt, Madelon A; Arns, Martijn

    2018-03-01

    Nonlinear analysis of EEG recordings allows detection of characteristics that would probably be neglected by linear methods. This study aimed to determine a suitable epoch length for nonlinear analysis of EEG data based on its recurrence rate in EEG alpha activity (electrodes Fz, Oz, and Pz) from 28 healthy and 64 major depressive disorder subjects. Two nonlinear metrics, Lempel-Ziv complexity and scaling index, were applied in sliding windows of 20 seconds shifted every 1 second and in nonoverlapping windows of 1 minute. In addition, linear spectral analysis was carried out for comparison with the nonlinear results. The analysis with sliding windows showed that the cortical dynamics underlying alpha activity had a recurrence period of around 40 seconds in both groups. In the analysis with nonoverlapping windows, long-term nonstationarities entailed changes over time in the nonlinear dynamics that became significantly different between epochs across time, which was not detected with the linear spectral analysis. Findings suggest that epoch lengths shorter than 40 seconds neglect information in EEG nonlinear studies. In turn, linear analysis did not detect characteristics from long-term nonstationarities in EEG alpha waves of control subjects and patients with major depressive disorder patients. We recommend that application of nonlinear metrics in EEG time series, particularly of alpha activity, should be carried out with epochs around 60 seconds. In addition, this study aimed to demonstrate that long-term nonlinearities are inherent to the cortical brain dynamics regardless of the presence or absence of a mental disorder.

  16. Sulforaphane protects cortical neurons against 5-S-cysteinyl-dopamine-induced toxicity through the activation of ERK1/2, Nrf-2 and the upregulation of detoxification enzymes.

    Science.gov (United States)

    Vauzour, David; Buonfiglio, Maria; Corona, Giulia; Chirafisi, Joselita; Vafeiadou, Katerina; Angeloni, Cristina; Hrelia, Silvana; Hrelia, Patrizia; Spencer, Jeremy P E

    2010-04-01

    The degeneration of dopaminergic neurons in the substantia nigra has been linked to the formation of the endogenous neurotoxin 5-S-cysteinyl-dopamine. Sulforaphane (SFN), an isothiocyanate derived from the corresponding precursor glucosinolate found in cruciferous vegetables has been observed to exert a range of biological activities in various cell populations. In this study, we show that SFN protects primary cortical neurons against 5-S-cysteinyl-dopamine induced neuronal injury. Pre-treatment of cortical neurons with SFN (0.01-1 microM) resulted in protection against 5-S-cysteinyl-dopamine-induced neurotoxicity, which peaked at 100 nM. This protection was observed to be mediated by the ability of SFN to modulate the extracellular signal-regulated kinase 1 and 2 and the activation of Kelch-like ECH-associated protein 1/NF-E2-related factor-2 leading to the increased expression and activity of glutathione-S-transferase (M1, M3 and M5), glutathione reductase, thioredoxin reductase and NAD(P)H oxidoreductase 1. These data suggest that SFN stimulates the NF-E2-related factor-2 pathway of antioxidant gene expression in neurons and may protect against neuronal injury relevant to the aetiology of Parkinson's disease.

  17. Calpain activation and disturbance of autophagy are induced in cortical neurons in vitro by exposure to HA/β-Ga2O3:Cr3+ nanoparticles.

    Science.gov (United States)

    Lei, Yu; Wang, Chengkun; Jiang, Quan; Sun, Xiaoyi; Du, Yongzhong; Zhu, Yaofeng; Lu, Yingmei

    2018-01-01

    The toxicity of engineered nanoparticles remains a concern. The knowledge of biohazards associated with particular nanoparticles is crucial to make this cutting-edge technology more beneficial and safe. Here, we evaluated the toxicity of Ga 2 O 3 nanoparticles (NPs), which are frequently used to enhance the performance of metal catalysts in a variety of catalytic reactions. The potential inflammatory signaling associated with the toxicity of HA/β-Ga 2 O 3 :Cr 3+ NPs in primary cortical neurons was examined. We observed a dose-dependent decrease in cell viability and an increase in apoptosis in neurons following various concentrations (0, 1, 5, 25, 50, 100 µg/ml) of HA/β-Ga 2 O 3 :Cr 3+ NPs treatment. Consistently, constitutively active forms of calcineurin (48 kDa) were significantly elevated in cultured primary cortical neurons, which was consistent with calpain activation indicated by the breakdown products of spectrin. Moreover, HA/β-Ga 2 O 3 :Cr 3+ NPs result in the elevation of LC3-II formation, SQSTM/p62, and Cathepsin B, whereas phosphorylation of CaMKII (Thr286) and Synapsin I (Ser603) were downregulated in the same context. Taken together, these results demonstrate for the first time that calpain activation and a disturbance of autophagy signaling are evoked by exposure to HA/β-Ga 2 O 3 :Cr 3+ NPs, which may contribute to neuronal injury in vitro .

  18. Calpain activation and disturbance of autophagy are induced in cortical neurons in vitro by exposure to HA/β-Ga2O3:Cr3+ nanoparticles

    Directory of Open Access Journals (Sweden)

    Yu Lei

    2018-02-01

    Full Text Available The toxicity of engineered nanoparticles remains a concern. The knowledge of biohazards associated with particular nanoparticles is crucial to make this cutting-edge technology more beneficial and safe. Here, we evaluated the toxicity of Ga2O3 nanoparticles (NPs, which are frequently used to enhance the performance of metal catalysts in a variety of catalytic reactions. The potential inflammatory signaling associated with the toxicity of HA/β-Ga2O3:Cr3+ NPs in primary cortical neurons was examined. We observed a dose-dependent decrease in cell viability and an increase in apoptosis in neurons following various concentrations (0, 1, 5, 25, 50, 100 µg/ml of HA/β-Ga2O3:Cr3+ NPs treatment. Consistently, constitutively active forms of calcineurin (48 kDa were significantly elevated in cultured primary cortical neurons, which was consistent with calpain activation indicated by the breakdown products of spectrin. Moreover, HA/β-Ga2O3:Cr3+ NPs result in the elevation of LC3-II formation, SQSTM/p62, and Cathepsin B, whereas phosphorylation of CaMKII (Thr286 and Synapsin I (Ser603 were downregulated in the same context. Taken together, these results demonstrate for the first time that calpain activation and a disturbance of autophagy signaling are evoked by exposure to HA/β-Ga2O3:Cr3+ NPs, which may contribute to neuronal injury in vitro.

  19. Neonatal pain-related stress, functional cortical activity and visual-perceptual abilities in school-age children born at extremely low gestational age.

    Science.gov (United States)

    Doesburg, Sam M; Chau, Cecil M; Cheung, Teresa P L; Moiseev, Alexander; Ribary, Urs; Herdman, Anthony T; Miller, Steven P; Cepeda, Ivan L; Synnes, Anne; Grunau, Ruth E

    2013-10-01

    Children born very prematurely (pain-related stress during neonatal intensive care has been proposed to contribute to altered neurocognitive development in these children. Due to critical periods in the development of thalamocortical systems, the immature brain of infants born at extremely low gestational age (ELGA; pain. In a cohort of school-age children followed since birth we assessed relations between functional brain activity measured using magnetoencephalogragy (MEG), visual-perceptual abilities and cumulative neonatal pain. We demonstrated alterations in the spectral structure of spontaneous cortical oscillatory activity in ELGA children at school-age. Cumulative neonatal pain-related stress was associated with changes in background cortical rhythmicity in these children, and these alterations in spontaneous brain oscillations were negatively correlated with visual-perceptual abilities at school-age, and were not driven by potentially confounding neonatal variables. These findings provide the first evidence linking neonatal pain-related stress, the development of functional brain activity, and school-age cognitive outcome in these vulnerable children. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. Cortical Visual Impairment

    Science.gov (United States)

    ... resolves by one year of life. Is “cortical blindness” the same thing as CVI? Cortical blindness is ... What visual characteristics are associated with CVI? • Distinct color preferences • Variable level of vision loss, often demonstrating ...

  1. Using fMRI to Detect Activation of the Cortical and Subcortical Auditory Centers: Development of a Standard Protocol for a Conventional 1.5-T MRI Scanner

    International Nuclear Information System (INIS)

    Tae, Woo Suk; Kim, Sam Soo; Lee, Kang Uk; Lee, Seung Hwan; Nam, Eui Cheol; Choi, Hyun Kyung

    2009-01-01

    We wanted to develop a standard protocol for auditory functional magnetic resonance imaging (fMRI) for detecting blood oxygenation level-dependent (BOLD) responses at the cortical and subcortical auditory centers with using a 1.5-T MRI scanner. Fourteen normal volunteers were enrolled in the study. The subjects were stimulated by four repetitions of 32 sec each with broadband white noise and silent period blocks as a run (34 echo planar images [EPIs]). Multiple regression analysis for the individual analysis and one-sample t-tests for the group analysis were applied (FDR, p <0.05). The auditory cortex was activated in most of the volunteers (left 100% and right 92.9% at an uncorrected p value <0.05, and left 92.9% and right 92.9% at an uncorreced p value <0.01). The cochlear nuclei (100%, 85.7%), inferior colliculi (71.4%, 64.3%), medial geniculate bodies (64.3%, 35.7%) and superior olivary complexes (35.7%, 35.7%) showed significant BOLD responses at uncorrected p values of <0.05 and p <0.01, respectively. On the group analysis, the cortical and subcortical auditory centers showed significant BOLD responses (FDR, p <0.05), except for the superior olivary complex. The signal intensity time courses of the auditory centers showed biphasic wave forms. We successfully visualized BOLD responses at the cortical and subcortical auditory centers using appropriate sound stimuli and an image acquisition method with a 1.5-T MRI scanner

  2. Amitriptyline up-regulates connexin43-gap junction in rat cultured cortical astrocytes via activation of the p38 and c-Fos/AP-1 signalling pathway.

    Science.gov (United States)

    Morioka, N; Suekama, K; Zhang, F F; Kajitani, N; Hisaoka-Nakashima, K; Takebayashi, M; Nakata, Y

    2014-06-01

    Intercellular communication via gap junctions, comprised of connexin (Cx) proteins, allow for communication between astrocytes, which in turn is crucial for maintaining CNS homeostasis. The expression of Cx43 is decreased in post-mortem brains from patients with major depression. A potentially novel mechanism of tricyclic antidepressants is to increase the expression and functioning of gap junctions in astrocytes. The effect of amitriptyline on the expression of Cx43 and gap junction intercellular communication (GJIC) in rat primary cultured cortical astrocytes was investigated. We also investigated the role of p38 MAPK intracellular signalling pathway in the amitriptyline-induced expression of Cx43 and GJIC. Treatment with amitriptyline for 48 h significantly up-regulated Cx43 mRNA, protein and GJIC. The up-regulation of Cx43 was not monoamine-related since noradrenaline, 5-HT and dopamine did not induce Cx43 expression and pretreatment with α- and β-adrenoceptor antagonists had no effect. Intracellular signalling involved p38 MAPK, as amitriptyline significantly increased p38 MAPK phosphorylation and Cx43 expression and GJIC were significantly blocked by the p38 inhibitor SB 202190. Furthermore, amitriptyline-induced Cx43 expression and GJIC were markedly reduced by transcription factor AP-1 inhibitors (curcumin and tanshinone IIA). The translocation of c-Fos from the cytosol and the nucleus of cortical astrocytes was increased by amitriptyline, and this response was dependent on p38 activity. These findings indicate a novel mechanism of action of amitriptyline through cortical astrocytes, and further suggest that targeting this mechanism could lead to the development of a new class of antidepressants. © 2014 The British Pharmacological Society.

  3. Posture Used in fMRI-PET Elicits Reduced Cortical Activity and Altered Hemispheric Asymmetry with Respect to Sitting Position: An EEG Resting State Study

    Directory of Open Access Journals (Sweden)

    Chiara Spironelli

    2017-12-01

    Full Text Available Horizontal body position is a posture typically adopted for sleeping or during brain imaging recording in both neuroscience experiments and diagnostic situations. Recent literature showed how this position and similar ones with head down are associated to reduced plasticity, impaired pain and emotional responses. The present study aimed at further understanding the decrease of cortical activity associated with horizontal body position by measuring high-frequency EEG bands – typically associated with high-level cognitive activation – in a resting state experimental condition. To this end, two groups of 16 female students were randomly assigned to either sitting control (SC or 2-h horizontal Bed Rest condition (hBR while EEG was recorded from 38 scalp recording sites. The hBR group underwent several body transitions, from sitting to supine, and from supine to sitting. Results revealed a clear effect of horizontal posture: the hBR group showed, compared to its baseline and to SC, reduced High-Beta and Gamma EEG band amplitudes throughout the 2-h of hBR condition. In addition, before and after the supine condition, hBR group as well as SC exhibited a greater left vs. right frontal activation in both EEG bands while, on the contrary, the supine position induced a bilateral and reduced activation in hBR participants. The cortical sources significantly more active in SC compared with hBR participants included the left Inferior Frontal Gyrus and left Insula. Results are discussed in relation to the differences among neuroimaging methods (e.g., fMRI, EEG, NIRS, which can be partially explained by posture-induced neural network changes.

  4. Time Courses of Cortical Glucose Metabolism and Microglial Activity Across the Life Span of Wild-Type Mice: A PET Study.

    Science.gov (United States)

    Brendel, Matthias; Focke, Carola; Blume, Tanja; Peters, Finn; Deussing, Maximilian; Probst, Federico; Jaworska, Anna; Overhoff, Felix; Albert, Nathalie; Lindner, Simon; von Ungern-Sternberg, Barbara; Bartenstein, Peter; Haass, Christian; Kleinberger, Gernot; Herms, Jochen; Rominger, Axel

    2017-12-01

    Contrary to findings in the human brain, 18 F-FDG PET shows cerebral hypermetabolism of aged wild-type (WT) mice relative to younger animals, supposedly due to microglial activation. Therefore, we used dual-tracer small-animal PET to examine directly the link between neuroinflammation and hypermetabolism in aged mice. Methods: WT mice (5-20 mo) were investigated in a cross-sectional design using 18 F-FDG ( n = 43) and translocator protein (TSPO) ( 18 F-GE180; n = 58) small-animal PET, with volume-of-interest and voxelwise analyses. Biochemical analysis of plasma cytokine levels and immunohistochemical confirmation of microglial activity were also performed. Results: Age-dependent cortical hypermetabolism in WT mice relative to young animals aged 5 mo peaked at 14.5 mo (+16%, P mice. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  5. Persistent barrage firing in cortical interneurons can be induced in vivo and may be important for the suppression of epileptiform activity

    Directory of Open Access Journals (Sweden)

    Norimitsu eSuzuki

    2014-03-01

    Full Text Available Neural circuits are typically maintained in a state of dynamic equilibrium by balanced synaptic excitation and inhibition. However, brain regions that are particularly susceptible to epilepsy may have evolved additional specialized mechanisms for inhibiting overexcitation. Here we identify one such possible mechanism in the cerebral cortex and hippocampus of mice. Recently it was reported that some types of GABAergic interneurons can slowly integrate excitatory inputs until eventually they fire persistently in the absence of the original stimulus. This property, called persistent firing or retroaxonal barrage firing, is of unknown physiological importance. We show that two common types of interneurons in cortical regions, neurogliaform cells and fast-spiking multipolar cells, are unique in exhibiting barrage firing in acute slices (~85% and ~23% success rate for induction, respectively. Barrage firing can also be induced in vivo, although the success rate for induction is lower (~60% in neurogliaform cells. In slices, barrage firing could reliably be triggered by trains of excitatory synaptic input, as well as by exposure to proconvulsant bath solutions (elevated extracellular K+, blockade of GABAA receptors. Using pair recordings in slices, we confirmed that barrage-firing neurogliaform cells can produce synaptic inhibition of nearby pyramidal neurons, and that this inhibition outlasts the original excitation. The ubiquity of neurogliaform and fast-spiking cells, together with their ability to fire persistently following excessive excitation, suggests that these interneurons may function as cortical sentinels, imposing an activity-dependent brake on undesirable neuronal hyperexcitability.

  6. Determination of calcium, phosphorus, and the calcium/phosphorus ratio in cortical bone from the human femoral neck by neutron activation analysis

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Tzaphlidou, Margaret

    2002-01-01

    Concentrations of Ca and P as well as the Ca/P ratio were estimated in intact cortical bone samples from the femoral neck of healthy humans, 33 women and 45 men, aged from 15 to 55 yr using instrumental neutron activation analysis. Mean values (M±SD) for the investigated parameters (on dry weight basis) were: 23.0±3.9%, 10.7±2.4% and 2.17±0.31, respectively. No statistically significant differences of the above parameters were observed related either to age or sex. The mean values for Ca, P and Ca/P ratio were within a very wide range of published data and close to their median. The individual variation for the Ca/P ratio in cortical bone from the healthy human femoral neck was lower than those for Ca and P separately. This means that specificity of Ca/P ratio is better than those of Ca and P concentrations are and may be more reliable for diagnosis of bone disorders

  7. Role of secondary sensory cortices in emotional memory storage and retrieval in rats.

    Science.gov (United States)

    Sacco, Tiziana; Sacchetti, Benedetto

    2010-08-06

    Visual, acoustic, and olfactory stimuli associated with a highly charged emotional situation take on the affective qualities of that situation. Where the emotional meaning of a given sensory experience is stored is a matter of debate. We found that excitotoxic lesions of auditory, visual, or olfactory secondary sensory cortices impaired remote, but not recent, fear memories in rats. Amnesia was modality-specific and not due to an interference with sensory or emotional processes. In these sites, memory persistence was dependent on ongoing protein kinase Mzeta activity and was associated with an increased activity of layers II-IV, thus suggesting a synaptic strengthening of corticocortical connections. Lesions of the same areas left intact the memory of sensory stimuli not associated with any emotional charge. We propose that secondary sensory cortices support memory storage and retrieval of sensory stimuli that have acquired a behavioral salience with the experience.

  8. Ethanol-induced transcriptional activation of programmed cell death 4 (Pdcd4 is mediated by GSK-3β signaling in rat cortical neuroblasts.

    Directory of Open Access Journals (Sweden)

    Amanjot Kaur Riar

    Full Text Available Ingestion of ethanol (ETOH during pregnancy induces grave abnormalities in developing fetal brain. We have previously reported that ETOH induces programmed cell death 4 (PDCD4, a critical regulator of cell growth, in cultured fetal cerebral cortical neurons (PCNs and in the cerebral cortex in vivo and affect protein synthesis as observed in Fetal Alcohol Spectrum Disorder (FASD. However, the mechanism which activates PDCD4 in neuronal systems is unclear and understanding this regulation may provide a counteractive strategy to correct the protein synthesis associated developmental changes seen in FASD. The present study investigates the molecular mechanism by which ethanol regulates PDCD4 in cortical neuroblasts, the immediate precursor of neurons. ETOH treatment significantly increased PDCD4 protein and transcript expression in spontaneously immortalized rat brain neuroblasts. Since PDCD4 is regulated at both the post-translational and post-transcriptional level, we assessed ETOH's effect on PDCD4 protein and mRNA stability. Chase experiments demonstrated that ETOH does not significantly impact either PDCD4 protein or mRNA stabilization. PDCD4 promoter-reporter assays confirmed that PDCD4 is transcriptionally regulated by ETOH in neuroblasts. Given a critical role of glycogen synthase kinase 3β (GSK-3β signaling in regulating protein synthesis and neurotoxic mechanisms, we investigated the involvement of GSK-3β and showed that multifunctional GSK-3β was significantly activated in response to ETOH in neuroblasts. In addition, we found that ETOH-induced activation of PDCD4 was inhibited by pharmacologic blockade of GSK-3β using inhibitors, lithium chloride (LiCl and SB-216763 or siRNA mediated silencing of GSK-3β. These results suggest that ethanol transcriptionally upregulates PDCD4 by enhancing GSK-3β signaling in cortical neuroblasts. Further, we demonstrate that canonical Wnt-3a/GSK-3β signaling is involved in regulating PDCD4 protein

  9. Protein kinase D stabilizes aldosterone-induced ERK1/2 MAP kinase activation in M1 renal cortical collecting duct cells to promote cell proliferation.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-01-01

    Aldosterone elicits transcriptional responses in target tissues and also rapidly stimulates the activation of protein kinase signalling cascades independently of de novo protein synthesis. Here we investigated aldosterone-induced cell proliferation and extra-cellular regulated kinase 1 and 2 (ERK1\\/2) mitogen activated protein (MAP) kinase signalling in the M1 cortical collecting duct cell line (M1-CCD). Aldosterone promoted the proliferative growth of M1-CCD cells, an effect that was protein kinase D1 (PKD1), PKCdelta and ERK1\\/2-dependent. Aldosterone induced the rapid activation of ERK1\\/2 with peaks of activation at 2 and 10 to 30 min after hormone treatment followed by sustained activation lasting beyond 120 min. M1-CCD cells suppressed in PKD1 expression exhibited only the early, transient peaks in ERK1\\/2 activation without the sustained phase. Aldosterone stimulated the physical association of PKD1 with ERK1\\/2 within 2 min of treatment. The mineralocorticoid receptor (MR) antagonist RU28318 inhibited the early and late phases of aldosterone-induced ERK1\\/2 activation, and also aldosterone-induced proliferative cell growth. Aldosterone induced the sub-cellular redistribution of ERK1\\/2 to the nuclei at 2 min and to cytoplasmic sites, proximal to the nuclei after 30 min. This sub-cellular distribution of ERK1\\/2 was inhibited in cells suppressed in the expression of PKD1.

  10. 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.

  11. Cortical activation in profoundly deaf patients during cochlear implant stimulation demonstrated by H2(15)O PET

    International Nuclear Information System (INIS)

    Herzog, H.; Lamprecht, A.; Kuehn, A.R.; Roden, W.; Vosteen, K.H.; Feinendegen, L.E.

    1991-01-01

    Cochlear implants (CIs) are used to provide sensations of sound to profoundly deaf patients. The performance of the CI is assessed mainly by the subjective reports of patients. The aim of this study was to look for objective cortical responses to the stimulation of the CI. Two postlingually and two prelingually deaf patients were investigated by positron emission tomography (PET) using 15 O-labeled water (H 2 15 O) to determine the regional cerebral blood flow (rCBF). Instead of quantifying rCBF in absolute terms, it was estimated by referring the regional tissue concentration of H 2 15 O to the mean whole brain concentration. CI stimulation encoded from white noise and sequential words led to an increased rCBF in the primary and secondary (Wernicke) auditory cortex. Relative elevations of up to 33% were observed bilaterally, although they were higher contralateral to the CI. These results were obtained not only in the postlingually deaf patients but also in two patients who had never been able to hear. Thus, it could be demonstrated that PET measurements of cerebral H 2 15 O distribution yield objective responses of the central auditory system during electrical stimulation by CIs in profoundly deaf patients

  12. Big data challenges in decoding cortical activity in a human with quadriplegia to inform a brain computer interface.

    Science.gov (United States)

    Friedenberg, David A; Bouton, Chad E; Annetta, Nicholas V; Skomrock, Nicholas; Mingming Zhang; Schwemmer, Michael; Bockbrader, Marcia A; Mysiw, W Jerry; Rezai, Ali R; Bresler, Herbert S; Sharma, Gaurav

    2016-08-01

    Recent advances in Brain Computer Interfaces (BCIs) have created hope that one day paralyzed patients will be able to regain control of their paralyzed limbs. As part of an ongoing clinical study, we have implanted a 96-electrode Utah array in the motor cortex of a paralyzed human. The array generates almost 3 million data points from the brain every second. This presents several big data challenges towards developing algorithms that should not only process the data in real-time (for the BCI to be responsive) but are also robust to temporal variations and non-stationarities in the sensor data. We demonstrate an algorithmic approach to analyze such data and present a novel method to evaluate such algorithms. We present our methodology with examples of decoding human brain data in real-time to inform a BCI.

  13. Ethanol induces cell-cycle activity and reduces stem cell diversity to alter both regenerative capacity and differentiation potential of cerebral cortical neuroepithelial precursors

    Directory of Open Access Journals (Sweden)

    Tingling Joseph D

    2005-09-01

    Full Text Available Abstract Background The fetal cortical neuroepithelium is a mosaic of distinct progenitor populations that elaborate diverse cellular fates. Ethanol induces apoptosis and interferes with the survival of differentiating neurons. However, we know little about ethanol's effects on neuronal progenitors. We therefore exposed neurosphere cultures from fetal rat cerebral cortex, to varying ethanol concentrations, to examine the impact of ethanol on stem cell fate. Results Ethanol promoted cell cycle progression, increased neurosphere number and increased diversity in neurosphere size, without inducing apoptosis. Unlike controls, dissociated cortical progenitors exposed to ethanol exhibited morphological evidence for asymmetric cell division, and cells derived from ethanol pre-treated neurospheres exhibited decreased proliferation capacity. Ethanol significantly reduced the numbers of cells expressing the stem cell markers CD117, CD133, Sca-1 and ABCG2, without decreasing nestin expression. Furthermore, ethanol-induced neurosphere proliferation was not accompanied by a commensurate increase in telomerase activity. Finally, cells derived from ethanol-pretreated neurospheres exhibited decreased differentiation in response to retinoic acid. Conclusion The reduction in stem cell number along with a transient ethanol-driven increase in cell proliferation, suggests that ethanol promotes stem to blast cell maturation, ultimately depleting the reserve proliferation capacity of neuroepithelial cells. However, the lack of a concomitant change in telomerase activity suggests that neuroepithelial maturation is accompanied by an increased potential for genomic instability. Finally, the cellular phenotype that emerges from ethanol pre-treated, stem cell depleted neurospheres is refractory to additional differentiation stimuli, suggesting that ethanol exposure ablates or delays subsequent neuronal differentiation.

  14. Is cortical bone hip? What determines cortical bone properties?

    Science.gov (United States)

    Epstein, Sol

    2007-07-01

    Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

  15. Activation of the mouse primary visual cortex by medial prefrontal subregion stimulation is not mediated by cholinergic basalo-cortical projections

    Directory of Open Access Journals (Sweden)

    Hoang Nam eNguyen

    2015-02-01

    Full Text Available The medial prefrontal cortex (mPFC exerts top-down control of primary visual cortex (V1 activity. As there is no direct neuronal projection from mPFC to V1, this functional connection may use an indirect route, i.e., via basalo-cortical cholinergic projections. The cholinergic projections to V1 originate from neurons in the horizontal limb of the diagonal band of Broca (HDB, which receive neuronal projections from the ventral part of the mPFC, composed of prelimbic (PrL and infralimbic cortices (IL. Therefore, the objective of this study was to determine whether electrical stimulation of mice mPFC subregions activate 1 V1 neurons and 2 HDB cholinergic neurons, suggesting that the HDB serves as a relay point in the mPFC-V1 interaction. Neuronal activation was quantified using c-Fos immunocytochemistry or thallium autometallography for each V1 layer using automated particle analysis tools and optical density measurement. Stimulation of IL and PrL induced significantly higher c-Fos expression or thallium labelling in layers II/III and V of V1 in the stimulated hemisphere only. A HDB cholinergic neuron-specific lesion by saporin administration reduced IL-induced c-Fos expression in layers II/III of V1 but not in layer V. However, there was no c-Fos expression or thallium labelling in the HDB neurons, suggesting that this area was not activated by IL stimulation. Stimulation of another mPFC subarea, the anterior cingulate cortex (AC, which is involved in attention and receives input from V1, activated neither V1 nor HDB. The present results indicate that IL and PrL, but not AC, stimulation activates V1 with the minor involvement of the HDB cholinergic projections. These results suggest a functional link between the ventral mPFC and V1, but this function is only marginally supported by HDB cholinergic neurons and may involve other brain regions.

  16. Cortical feedback control of olfactory bulb circuits.

    Science.gov (United States)

    Boyd, Alison M; Sturgill, James F; Poo, Cindy; Isaacson, Jeffry S

    2012-12-20

    Olfactory cortex pyramidal cells integrate sensory input from olfactory bulb mitral and tufted (M/T) cells and project axons back to the bulb. However, the impact of cortical feedback projections on olfactory bulb circuits is unclear. Here, we selectively express channelrhodopsin-2 in olfactory cortex pyramidal cells and show that cortical feedback projections excite diverse populations of bulb interneurons. Activation of cortical fibers directly excites GABAergic granule cells, which in turn inhibit M/T cells. However, we show that cortical inputs preferentially target short axon cells that drive feedforward inhibition of granule cells. In vivo, activation of olfactory cortex that only weakly affects spontaneous M/T cell firing strongly gates odor-evoked M/T cell responses: cortical activity suppresses odor-evoked excitation and enhances odor-evoked inhibition. Together, these results indicate that although cortical projections have diverse actions on olfactory bulb microcircuits, the net effect of cortical feedback on M/T cells is an amplification of odor-evoked inhibition. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

    2016-09-10

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

  18. The Ongoing and Open-Ended Simulation

    Science.gov (United States)

    Cohen, Alexander

    2016-01-01

    This case study explores a novel form of classroom simulation that differs from published examples in two important respects. First, it is ongoing. While most simulations represent a single learning episode embedded within a course, the ongoing simulation is a continuous set of interrelated events and decisions that accompany learning throughout…

  19. Acute stimulation of dissociated cortical neurons of newborn rats with orexin A : Effect on the network activity

    NARCIS (Netherlands)

    Stoyanova, I.I.; le Feber, J.; Rutten, W.L.C.; El Haj, Alicia; Bader, Dan

    2011-01-01

    Orexin A (OXA) and B are hypothalamic neu-ropeptides with recognized importance in the physiological regulation of various brain activities, including sleep/wakefulness, learning and memory, locomotion, auto-nomic control. Orexin activity is mediated by two types of receptors; OR1 binds OXA with

  20. Modulation of cortical activity during comprehension of familiar and unfamiliar text topics in speed reading and speed listening.

    Science.gov (United States)

    Buchweitz, Augusto; Mason, Robert A; Meschyan, Gayane; Keller, Timothy A; Just, Marcel Adam

    2014-12-01

    Brain activation associated with normal and speeded comprehension of expository texts on familiar and unfamiliar topics was investigated in reading and listening. The goal was to determine how brain activation and the comprehension processes it reflects are modulated by comprehension speed and topic familiarity. Passages on more familiar topics differentially activated a set of areas in the anterior temporal lobe and medial frontal gyrus, areas often associated with text-level integration processes, which we interpret to reflect integration of previous knowledge with the passage content. Passages presented at the faster presentation resulted in more activation of a network of frontal areas associated with strategic and working-memory processes (as well as visual or auditory sensory-related regions), which we interpret to reflect maintenance of local coherence among briefly available passage segments. The implications of this research is that the brain system for text comprehension adapts to varying perceptual and knowledge conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Motivational mechanisms (BAS) and prefrontal cortical activation contribute to recognition memory for emotional words. rTMS effect on performance and EEG (alpha band) measures.

    Science.gov (United States)

    Balconi, Michela; Cobelli, Chiara

    2014-10-01

    The present research addressed the question of where memories for emotional words could be represented in the brain. A second main question was related to the effect of personality traits, in terms of the Behavior Activation System (BAS), in emotional word recognition. We tested the role of the left DLPFC (LDLPFC) by performing a memory task in which old (previously encoded targets) and new (previously not encoded distractors) positive or negative emotional words had to be recognized. High-BAS and low-BAS subjects were compared when a repetitive TMS (rTMS) was applied on the LDLPFC. We found significant differences between high-BAS vs. low-BAS subjects, with better performance for high-BAS in response to positive words. In parallel, an increased left cortical activity (alpha desynchronization) was observed for high-BAS in the case of positive words. Thus, we can conclude that the left approach-related hemisphere, underlying BAS, may support faster recognition of positive words. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Cortical activation during Braille reading is influenced by early visual experience in subjects with severe visual disability: a correlational fMRI study.

    Science.gov (United States)

    Melzer, P; Morgan, V L; Pickens, D R; Price, R R; Wall, R S; Ebner, F F

    2001-11-01

    Functional magnetic resonance imaging was performed on blind adults resting and reading Braille. The strongest activation was found in primary somatic sensory/motor cortex on both cortical hemispheres. Additional foci of activation were situated in the parietal, temporal, and occipital lobes where visual information is processed in sighted persons. The regions were differentiated most in the correlation of their time courses of activation with resting and reading. Differences in magnitude and expanse of activation were substantially less significant. Among the traditionally visual areas, the strength of correlation was greatest in posterior parietal cortex and moderate in occipitotemporal, lateral occipital, and primary visual cortex. It was low in secondary visual cortex as well as in dorsal and ventral inferior temporal cortex and posterior middle temporal cortex. Visual experience increased the strength of correlation in all regions except dorsal inferior temporal and posterior parietal cortex. The greatest statistically significant increase, i.e., approximately 30%, was in ventral inferior temporal and posterior middle temporal cortex. In these regions, words are analyzed semantically, which may be facilitated by visual experience. In contrast, visual experience resulted in a slight, insignificant diminution of the strength of correlation in dorsal inferior temporal cortex where language is analyzed phonetically. These findings affirm that posterior temporal regions are engaged in the processing of written language. Moreover, they suggest that this function is modified by early visual experience. Furthermore, visual experience significantly strengthened the correlation of activation and Braille reading in occipital regions traditionally involved in the processing of visual features and object recognition suggesting a role for visual imagery. Copyright 2001 Wiley-Liss, Inc.

  3. Differential Regulation of Disheveled in a Novel Vegetal Cortical Domain in Sea Urchin Eggs and Embryos: Implications for the Localized Activation of Canonical Wnt Signaling

    Science.gov (United States)

    Peng, ChiehFu Jeff; Wikramanayake, Athula H.

    2013-01-01

    Pattern formation along the animal-vegetal (AV) axis in sea urchin embryos is initiated when canonical Wnt (cWnt) signaling is activated in vegetal blastomeres. The mechanisms that restrict cWnt signaling to vegetal blastomeres are not well understood, but there is increasing evidence that the egg’s vegetal cortex plays a critical role in this process by mediating localized “activation” of Disheveled (Dsh). To investigate how Dsh activity is regulated along the AV axis, sea urchin-specific Dsh antibodies were used to examine expression, subcellular localization, and post-translational modification of Dsh during development. Dsh is broadly expressed during early sea urchin development, but immunolocalization studies revealed that this protein is enriched in a punctate pattern in a novel vegetal cortical domain (VCD) in the egg. Vegetal blastomeres inherit this VCD during embryogenesis, and at the 60-cell stage Dsh puncta are seen in all cells that display nuclear β-catenin. Analysis of Dsh post-translational modification using two-dimensional Western blot analysis revealed that compared to Dsh pools in the bulk cytoplasm, this protein is differentially modified in the VCD and in the 16-cell stage micromeres that partially inherit this domain. Dsh localization to the VCD is not directly affected by disruption of microfilaments and microtubules, but unexpectedly, microfilament disruption led to degradation of all the Dsh pools in unfertilized eggs over a period of incubation suggesting that microfilament integrity is required for maintaining Dsh stability. These results demonstrate that a pool of differentially modified Dsh in the VCD is selectively inherited by the vegetal blastomeres that activate cWnt signaling in early embryos, and suggests that this domain functions as a scaffold for localized Dsh activation. Localized cWnt activation regulates AV axis patterning in many metazoan embryos. Hence, it is possible that the VCD is an evolutionarily conserved

  4. Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

    Science.gov (United States)

    Huys, Raoul; Jirsa, Viktor K.; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E.

    2016-01-01

    Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2–3. PMID:26778982

  5. Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing

    Science.gov (United States)

    Minami, Chihiro; Shimizu, Tomoko

    2017-01-01

    Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior. PMID:28459875

  6. Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing.

    Science.gov (United States)

    Minami, Chihiro; Shimizu, Tomoko; Mitani, Akira

    2017-01-01

    Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior.

  7. Cortical bone metastases

    International Nuclear Information System (INIS)

    Davis, T.M. Jr.; Rogers, L.F.; Hendrix, R.W.

    1986-01-01

    Twenty-five cases of bone metastases involving the cortex alone are reviewed. Seven patients had primary lung carcinoma, while 18 had primary tumors not previously reported to produce cortical bone metastases (tumors of the breast, kidney, pancreas, adenocarcinoma of unknown origin, multiple myeloma). Radiographically, these cortical lesions were well circumscribed, osteolytic, and produced soft-tissue swelling and occasional periosteal reaction. A recurrent pattern of metadiaphyseal involvement of the long bones of the lower extremity (particularly the femur) was noted, and is discussed. Findings reported in the literature, review, pathophysiology, and the role of skeletal radiographs, bone scans, and CT scans in evaluating cortical bone metastases are addressed

  8. Contralateral Cortical Organisation of Information in Visual Short-Term Memory: Evidence from Lateralized Brain Activity during Retrieval

    Science.gov (United States)

    Fortier-Gauthier, Ulysse; Moffat, Nicolas; Dell'Acqua, Robert; McDonald, John J.; Jolicoeur, Pierre

    2012-01-01

    We studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a…

  9. Sulforhodamine 101, a widely used astrocyte marker, can induce cortical seizure-like activity at concentrations commonly used

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Nedergaard, Maiken; Petersen, Nicolas Caesar

    2016-01-01

    Sulforhodamine 101 (SR101) is a preferential astrocyte marker widely used in 2-photon microscopy experiments. Here we show, that topical loading of two commonly used SR101 concentrations, 100 μM and 250 μM when incubated for 10 min, can induce seizure-like local field potential (LFP) activity in ...

  10. Methylated spirit burns: an ongoing problem.

    Science.gov (United States)

    Jansbeken, J R H; Vloemans, A F P M; Tempelman, F R H; Breederveld, R S

    2012-09-01

    Despite many educational campaigns we still see burns caused by methylated spirit every year. We undertook a retrospective study to analyse the impact of this problem. We retrospectively collected data of all patients with burns caused by methylated spirit over twelve years from 1996 to 2008. Our main endpoints were: incidence, age, mechanism of injury, total body surface area (TBSA) burned, burn depth, need for surgery and length of hospital stay. Ninety-seven patients with methylated spirit burns were included. During the study period there was no decrease in the number of patients annually admitted to the burn unit with methylated spirit burns. 28% of the patients (n=27) were younger than eighteen years old, 15% (n=15) were ten years old or younger. The most common cause of burns was carelessness in activities involving barbecues, campfires and fondues. Mean TBSA burned was 16% (SD 12.4). 70% (n=68) had full thickness burns. 66% (n=64) needed grafting. Mean length of hospital stay was 23 days (SD 24.7). The use of methylated spirit is an ongoing problem, which continues to cause severe burns in adults and children. Therefore methylated spirit should be banned in households. We suggest sale only in specialised shops, clear labelling and mandatory warnings. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  11. Virtual visual reminiscing pain stimulation of allodynia patients activates cortical representation of pain and emotions. fMRI study

    International Nuclear Information System (INIS)

    Ikemoto, Tatsunori; Ushida, Takahiro; Taniguchi, Shinichirou; Tania, Toshikazu; Zinchuk, V.; Morio, Kazuo; Sasaki, Toshikazu

    2004-01-01

    It is widely known that sensation of the pain is derived from sensory-discriminative factor and emotional factor. Especially in chronic pain, emotional factors and psychosocial backgrounds are more likely to contribute for the patients' discomfort. The aim of this study is to investigate how emotional factor of pain participates in intractable pain. We employed functional MRI (fMRI) to compare the brain activations occurring in the orthopaedic neuropathic pain patients with allodynia and normal individuals in response to the visual virtual painful experience. During fMRI scanning, a video demonstrating an actual tactile stimulation of the palm and its imitation were shown to participants. In contrast to normal individuals, allodynia patients also displayed activation of the areas reflecting emotions: frontal lobe and anterior cingulate. These findings suggest that brain have important role in the development and maintaining of peripheral originated chronic painful condition. (author)

  12. Cortical activities evoked by the signals ascending through unmyelinated C fibers in humans. A fMRI study

    International Nuclear Information System (INIS)

    Kakigi, Ryusuke; Qiu, Yunhai; Noguchi, Yasuki

    2006-01-01

    Acute pain is classified as first and second pain associated with rapidly conducting Aδ fibers and slowly conducting unmyelinated C fibers, respectively. First pain aims at achieving relative safety from the source of injury, whereas second pain, with its strong affective component, attracts longer-lasting attention and initiates behavioral responses in order to limit further injury and optimize recovery. Accordingly, the distinct brain representations for first and second pain should reflect distinct biological functions of both sensations. In this study, therefore, an event-related functional magnetic resonance imaging (fMRI) was used to investigate brain processing of the signals ascending from peripheral C and Aδ fibers evoked by phasic laser stimuli on the right hand in humans. The stimulation of both C and Aδ nociceptors activated the bilateral thalamus, bilateral secondary somatosensory cortex (SII), right (ipsilateral) middle insula, and bilateral Brodmann's area (BA) 24/32, with the majority of activity found in the posterior portion of the anterior cingulate cortex (pACC). However, magnitude of activity in the right (ipsilateral) BA32/8/6, including dorsal parts in the anterior portion of the ACC (aACC) and pre-supplementary motor area (pre-SMA), and the bilateral anterior insula was significantly stronger following the stimulation of C nociceptors than Aδ nociceptors. It was concluded that the activation of C nociceptors, related to second pain, evokes different brain processing from that of Aδ nociceptors, related to first pain, probably due to the differences in the emotional and motivational aspects of either pain, which are mainly related to the aACC, pre-SMA and anterior insula. (author)

  13. Long-term changes of activity of cortical neurons after status epilepticus induced at early developmental stages in rats

    Czech Academy of Sciences Publication Activity Database

    Doczi, J.; Bernášková, Klára; Kubová, Hana; Détari, L.; Világi, I.; Druga, Rastislav; Mareš, Pavel

    2003-01-01

    Roč. 352, č. 2 (2003), s. 125-128 ISSN 0304-3940 R&D Projects: GA ČR GA309/00/1643; GA ČR GA309/03/0770 Institutional research plan: CEZ:AV0Z5011922 Keywords : cerebral cortex * unit activity * consequences of status epilepticus Subject RIV: FH - Neurology Impact factor: 1.967, year: 2003

  14. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  15. Cortical regions activated by the subjective sense of perceptual coherence of environmental sounds: a proposal for a neuroscience of intuition.

    Science.gov (United States)

    Volz, Kirsten G; Rübsamen, Rudolf; von Cramon, D Yves

    2008-09-01

    According to the Oxford English Dictionary, intuition is "the ability to understand or know something immediately, without conscious reasoning." In other words, people continuously, without conscious attention, recognize patterns in the stream of sensations that impinge upon them. The result is a vague perception of coherence, which subsequently biases thought and behavior accordingly. Within the visual domain, research using paradigms with difficult recognition has suggested that the orbitofrontal cortex (OFC) serves as a fast detector and predictor of potential content that utilizes coarse facets of the input. To investigate whether the OFC is crucial in biasing task-specific processing, and hence subserves intuitive judgments in various modalities, we used a difficult-recognition paradigm in the auditory domain. Participants were presented with short sequences of distorted, nonverbal, environmental sounds and had to perform a sound categorization task. Imaging results revealed rostral medial OFC activation for such auditory intuitive coherence judgments. By means of a conjunction analysis between the present results and those from a previous study on visual intuitive coherence judgments, the rostral medial OFC was shown to be activated via both modalities. We conclude that rostral OFC activation during intuitive coherence judgments subserves the detection of potential content on the basis of only coarse facets of the input.

  16. Folate and S-adenosylmethionine modulate synaptic activity in cultured cortical neurons: acute differential impact on normal and apolipoprotein-deficient mice

    International Nuclear Information System (INIS)

    Serra, Michael; Chan, Amy; Dubey, Maya; Shea, Thomas B; Gilman, Vladimir

    2008-01-01

    Folate deficiency is accompanied by a decline in the cognitive neurotransmitter acetylcholine and a decline in cognitive performance in mice lacking apolipoprotein E (ApoE−/− mice), a low-density lipoprotein that regulates aspects of lipid metabolism. One direct consequence of folate deficiency is a decline in S-adenosylmethionine (SAM). Since dietary SAM supplementation maintains acetylcholine levels and cognitive performance in the absence of folate, we examined herein the impact of folate and SAM on neuronal synaptic activity. Embryonic cortical neurons from mice expressing or lacking ApoE (ApoE+/+ or −/−, respectively) were cultured for 1 month on multi-electrode arrays, and signaling was recorded. ApoE+/+ cultures displayed significantly more frequent spontaneous signals than ApoE−/− cultures. Supplementation with 166 µm SAM (not normally present in culture medium) increased signal frequency and decreased signal amplitude in ApoE+/+ cultures. SAM also increased the frequency of tightly clustered signal bursts. Folate deprivation reversibly reduced signal frequency in ApoE+/+ cultures; SAM supplementation maintained signal frequency despite folate deprivation. These findings support the importance of dietary supplementation with folate and SAM on neuronal health. Supplementation with 166 µm SAM did not alter signaling in ApoE−/− cultures, which may be a reflection of the reduced SAM levels in ApoE−/− mice. The differential impact of SAM on ApoE+/+ and −/− neurons underscores the combined impact of nutritional and genetic deficiencies on neuronal homeostasis. (communication)

  17. Curcumin produces neuroprotective effects via activating brain-derived neurotrophic factor/TrkB-dependent MAPK and PI-3K cascades in rodent cortical neurons.

    Science.gov (United States)

    Wang, Rui; Li, Yu-Hua; Xu, Ying; Li, Ying-Bo; Wu, Hong-Li; Guo, Hao; Zhang, Jian-Zhao; Zhang, Jing-Jie; Pan, Xue-Yang; Li, Xue-Jun

    2010-02-01

    Curcumin is a major constituent of curcuma longa, a traditional medicine used to manage mental disorders effectively in China. The neuroprotective effects of curcumin have been demonstrated in our previous studies. In the present research, we confirmed this effect by showing that curcumin application promoted the viability of cultured rodent cortical neurons. Moreover, when neurons were pretreated with tyrosine kinase B (TrkB) antibody, known to inhibit the activity of brain-derived neurotrophic factor (BDNF), the protective effect of curcumin was blocked. Additionally, treatment of curcumin increased BDNF and phosphor-TrkB and both of these enhancements can be suppressed by ERK and PI-3K inhibitors. The administration of curcumin led to increased levels of phosphor-ERK and AKT, which were each blocked by MAPK and PI-3K inhibitors. Furthermore, the curcumin-induced increase in phosphorylated cyclic AMP response element binding protein (CREB), which has been implicated as a possible mediator of antidepressant actions, was prevented by MAPK and PI-3K inhibitors. Therefore, we hypothesize the neuroprotection of curcumin might be mediated via BDNF/TrkB-MAPK/PI-3K-CREB signaling pathway. Copyright 2009. Published by Elsevier Inc.

  18. BoNT-A related changes of cortical activity in patients suffering from severe hand paralysis with arm spasticity following ischemic stroke.

    Science.gov (United States)

    Veverka, Tomáš; Hluštík, Petr; Tomášová, Zuzana; Hok, Pavel; Otruba, Pavel; Král, Michal; Tüdös, Zbyněk; Zapletalová, Jana; Herzig, Roman; Krobot, Alois; Kaňovský, Petr

    2012-08-15

    Investigations were performed to localize and analyze the botulinum toxin (BoNT-A) related changes of cerebral cortex activation in chronic stroke patients suffering from severe hand paralysis with arm spasticity. Effects on task- related cerebral activation were evaluated by functional magnetic resonance imaging (fMRI). 14 patients (5 males, 9 females, mean age 55.3 years) suffering from upper limb post-stroke spasticity were investigated. The change of arm spasticity was assessed by using the modified Ashworth scale (MAS). FMRI sessions were performed before (W0), four weeks (W4) and 11 weeks (W11) after BoNT-A application. Patients were scanned while performing imaginary movement with the impaired hand. Group fMRI analysis included patient age as a covariate. BoNT-A treatment was effective in alleviation of arm spasticity. Mean MAS was at Week 0: 2.5 (SD 0.53), at Week 4: 1.45 (SD 0.38), at Week 11: 2.32 (SD 0.44). Task-related fMRI prior to the treatment showed extensive activation of bilateral frontoparietal sensorimotor cortical areas, anterior cingulate gyrus, pallidum, thalamus and cerebellum. Effective BoNT-A treatment (W4) resulted in partial reduction of active network volume in most of the observed areas, whereas BoNT-free data (W11) revealed further volume reduction in the sensorimotor network. On direct comparison, significant activation decreases associated with BoNT-A treatment were located in areas outside the classical sensorimotor system, namely, ipsilesional lateral occipital cortex, supramarginal gyrus and precuneus cortex. On comparison of W4 and W11, no activation increases were found, instead, activation further decreased in ipsilesional insular cortex, contralesional superior frontal gyrus and bilateral frontal pole. Whole brain activation patterns during BoNT-A treatment of post-stroke arm spasticity and further follow up document predominantly gradual changes both within and outside the classical sensorimotor system. Copyright © 2012

  19. The modulation of venlafaxine on cortical activation of language area in healthy subjects with fMRI study.

    Science.gov (United States)

    Xie, Qi; Liu, Yan; Li, Chun-Yong; Song, Xue-Zhu; Wang, Jun; Han, Li-Xin; Bai, Hong-Min

    2012-10-01

    Previous studies have shown that selective serotonin reuptake inhibitors, activators of the cortex, apparently improved language functional recovery after brain damage rather than simply affective disorders. Our aim was to determine whether venlafaxine (an agonist of both norepinephrine and 5-hydroxytryptamine) could modulate language cortex function. A double-blind, crossover, randomized design was used to compare two 7-day treatment sessions with either venlafaxine (75 mg per day) or placebo. A functional magnetic resonance imaging experiment and two language function tests were performed on eight healthy males (mean age, 28.25 ± 3.15 years) at the end of each session, i.e., study entry, after venlafaxine, and after placebo (days 0, 7, and 18). Hyperactivation (venlafaxine minus placebo >0) or hypoactivation (placebo minus venlafaxine >0) by venlaxafine was assessed on the basis of the activation-baseline contrast. The naming score (P gyrus frontalis medius and the bilateral fusiform gyrus and the bilateral outer occipital lobes, (2) hyperactivation was observed in the adjoining area of posterior upper Broca area and premotor area in the dominant hemisphere in venlafaxine session (after venlafaxine), (3) the hyperactivation of the left gyrus frontalis medius on fMRI and the increase in naming test score were positively correlated, and (4) by contrast, we observed hypoactivation in the temporo-parieto-occipital region in venlafaxine session (after venlafaxine). This improvement may be related to increased phonics-related output in the frontal language cortex of the dominant hemisphere.

  20. Cortical Local Field Potential Power Is Associated with Behavioral Detection of Near-threshold Stimuli in the Rat Whisker System: Dissociation between Orbitofrontal and Somatosensory Cortices.

    Science.gov (United States)

    Rickard, Rachel E; Young, Andrew M J; Gerdjikov, Todor V

    2018-01-01

    There is growing evidence that ongoing brain oscillations may represent a key regulator of attentional processes and as such may contribute to behavioral performance in psychophysical tasks. OFC appears to be involved in the top-down modulation of sensory processing; however, the specific contribution of ongoing OFC oscillations to perception has not been characterized. Here we used the rat whiskers as a model system to further characterize the relationship between cortical state and tactile detection. Head-fixed rats were trained to report the presence of a vibrotactile stimulus (frequency = 60 Hz, duration = 2 sec, deflection amplitude = 0.01-0.5 mm) applied to a single vibrissa. We calculated power spectra of local field potentials preceding the onset of near-threshold stimuli from microelectrodes chronically implanted in OFC and somatosensory cortex. We found a dissociation between slow oscillation power in the two regions in relation to detection probability: Higher OFC but not somatosensory delta power was associated with increased detection probability. Furthermore, coherence between OFC and barrel cortex was reduced preceding successful detection. Consistent with the role of OFC in attention, our results identify a cortical network whose activity is differentially modulated before successful tactile detection.

  1. The Diversity of Cortical Inhibitory Synapses

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKubota

    2016-04-01

    Full Text Available The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their IPSP size is not uniform. Thus cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit.

  2. Mental Fatigue Alters Cortical Activation and Psychological Responses, Impairing Performance in a Distance-Based Cycling Trial

    Directory of Open Access Journals (Sweden)

    Flávio O. Pires

    2018-03-01

    Full Text Available Purpose: We sought to verify if alterations in prefrontal cortex (PFC activation and psychological responses would play along with impairments in pacing and performance of mentally fatigued cyclists.Materials and Methods: Eight recreational cyclists performed two preliminary sessions to familiarize them with the rapid visual information processing (RVP test, psychological scales and 20 km cycling time trial (TT20km (session 1, as well as to perform a VO2MAX test (session 2. Thereafter, they performed a TT20km either after a RVP test (30 min or a time-matched rest control session (session 3 and 4 in counterbalanced order. Performance and psychological responses were obtained throughout the TT20km while PFC electroencephalography (EEG was obtained at 10 and 20 km of the TT20km and throughout the RVP test. Increases in EEG theta band power indicated a mental fatigue condition. Repeated-measures mixed models design and post-hoc effect size (ES were used in comparisons.Results: Cyclists completed the trial ~2.7% slower in mental fatigue (34.3 ± 1.3 min than in control (33.4 ± 1.1 min, p = 0.02, very large ES, with a lower WMEAN (224.5 ± 17.9 W vs. 240.2 ± 20.9 W, respectively; p = 0.03; extremely large ES. There was a higher EEG theta band power during RVP test (p = 0.03; extremely large ES, which remained during the TT20km (p = 0.01; extremely large ES. RPE increased steeper in mental fatigue than in control, together with isolated reductions in motivation at 2th km (p = 0.04; extremely large ES, felt arousal at the 2nd and 4th km (p = 0.01; extremely large ES, and associative thoughts to exercise at the 6th and 16th km (p = 0.02; extremely large ES of the TT20km.Conclusions: Mentally fatigued recreational cyclists showed impaired performance, altered PFC activation and faster increase in RPE during a TT20km.

  3. Protein kinase D1 modulates aldosterone-induced ENaC activity in a renal cortical collecting duct cell line.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-08-30

    Aldosterone treatment of M1-CCD cells stimulated an increase in epithelial Na(+) channel (ENaC) alpha-subunit expression that was mainly localized to the apical membrane. PKD1-suppressed cells constitutively expressed ENaCalpha at low abundance, with no increase after aldosterone treatment. In the PKD1-suppressed cells, ENaCalpha was mainly localized proximal to the basolateral surface of the epithelium both before and after aldosterone treatment. Apical membrane insertion of ENaCbeta in response to aldosterone treatment was also sensitive to PKD1 suppression as was the aldosterone-induced rise in the amiloride-sensitive, trans-epithelial current (I(TE)). The interaction of the mineralocorticoid receptor (MR) with specific elements in the promoters of aldosterone responsive genes is stabilized by ligand interaction and phosphorylation. PKD1 suppression inhibited aldosterone-induced SGK-1 expression. The nuclear localization of MR was also blocked by PKD1 suppression and MEK antagonism implicating both these kinases in MR nuclear stabilization. PKD1 thus modulates aldosterone-induced ENaC activity through the modulation of sub-cellular trafficking and the stabilization of MR nuclear localization.

  4. Mitochondrial bioenergetics during the initiation of mercuric chloride-induced renal activity. II. Functional alterations of renal cortical mitochondria isolated after mercuric chloride treatment

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, J.M. (Veterans Administration Medical Center, Ann Arbor, MI); Harding, P.G.; Humes, H.D.

    1982-01-01

    The mitochondrial functional defects occurring in the early stages of nephrotoxic renal injury secondary to mercuric chloride have been characterized. No loss of cellular integrity or major mitochondrial structural alterations occurred within the first 3 hr after a subcutaneous injection of 5 mg/kg of HgCl/sub 2/. At 3 h, levels of Hg/sup 2 +/ in renal cortex and isolated renal cortical mitochondria were 1.87 and 0.72 nmol/mg of protein, respectively. Much evidence suggested that this Hg/sup 2 +/ had reached the mitochondria in situ and not during the isolation process. Mitochondria isolated beginning 1 h after treatment with HgCl/sub 2/ showed depressed ADP uptake. At 2 h, inhibitions of State 3 and 2,4-dinitrophenol uncoupled respiration were detected. Inhibition of 2,4-dinitrophenol-activated mitochondrial ATPase activity was present when measured on mitochondria isolated at 3 h. These effects were not reversed by 2 mM dithioerythritol, 50 mg/ml of albumin or 5 mM MgCl/sub 2/. Analysis of the data in the context of information available on the in vitro effects of HgCl/sub 2/ (Weinberg, J.M., Harding, P.G., and Humes, H.D. (1982) J. Biol. Chem. 257, 60-67) indicated that the mitochondrial functional effects could not be attributed to interaction of the mitochondria with Hg/sup 2 +/ during their isolation. These studies implicate compromised mitochondrial bioenergetic function as one of the earliest intracellular effects of Hg/sup 2 +/ in the production of nephrotoxicity but suggest that the intracellular process involves events in addition to those seen with direct exposure of mitochondria to Hg/sup 2 +/ in vitro.

  5. Persistence and storage of activity patterns in spiking recurrent cortical networks: modulation of sigmoid signals by after-hyperpolarization currents and acetylcholine.

    Science.gov (United States)

    Palma, Jesse; Grossberg, Stephen; Versace, Massimiliano

    2012-01-01

    Many cortical networks contain recurrent architectures that transform input patterns before storing them in short-term memory (STM). Theorems in the 1970's showed how feedback signal functions in rate-based recurrent on-center off-surround networks control this process. A sigmoid signal function induces a quenching threshold below which inputs are suppressed as noise and above which they are contrast-enhanced before pattern storage. This article describes how changes in feedback signaling, neuromodulation, and recurrent connectivity may alter pattern processing in recurrent on-center off-surround networks of spiking neurons. In spiking neurons, fast, medium, and slow after-hyperpolarization (AHP) currents control sigmoid signal threshold and slope. Modulation of AHP currents by acetylcholine (ACh) can change sigmoid shape and, with it, network dynamics. For example, decreasing signal function threshold and increasing slope can lengthen the persistence of a partially contrast-enhanced pattern, increase the number of active cells stored in STM, or, if connectivity is distance-dependent, cause cell activities to cluster. These results clarify how cholinergic modulation by the basal forebrain may alter the vigilance of category learning circuits, and thus their sensitivity to predictive mismatches, thereby controlling whether learned categories code concrete or abstract features, as predicted by Adaptive Resonance Theory. The analysis includes global, distance-dependent, and interneuron-mediated circuits. With an appropriate degree of recurrent excitation and inhibition, spiking networks maintain a partially contrast-enhanced pattern for 800 ms or longer after stimuli offset, then resolve to no stored pattern, or to winner-take-all (WTA) stored patterns with one or multiple winners. Strengthening inhibition prolongs a partially contrast-enhanced pattern by slowing the transition to stability, while strengthening excitation causes more winners when the network

  6. Persistence and storage of activity patterns in spiking recurrent cortical networks:Modulation of sigmoid signals by after-hyperpolarization currents and acetylcholine

    Directory of Open Access Journals (Sweden)

    Jesse ePalma

    2012-06-01

    Full Text Available Many cortical networks contain recurrent architectures that transform input patterns before storing them in short-term memory (STM. Theorems in the 1970’s showed how feedback signal functions in rate-based recurrent on-center off-surround networks control this process. A sigmoid signal function induces a quenching threshold below which inputs are suppressed as noise and above which they are contrast-enhanced before pattern storage. This article describes how changes in feedback signaling, neuromodulation, and recurrent connectivity may alter pattern processing in recurrent on-center off-surround networks of spiking neurons. In spiking neurons, fast, medium, and slow after-hyperpolarization (AHP currents control sigmoid signal threshold and slope. Modulation of AHP currents by acetylcholine (ACh can change sigmoid shape and, with it, network dynamics. For example, decreasing signal function threshold and increasing slope can lengthen the persistence of a partially contrast-enhanced pattern, increase the number of active cells stored in STM, or, if connectivity is distance-dependent, cause cell activities to cluster. These results clarify how cholinergic modulation by the basal forebrain may alter the vigilance of category learning circuits, and thus their sensitivity to predictive mismatches, thereby controlling whether learned categories code concrete or abstract features, as predicted by Adaptive Resonance Theory. The analysis includes global, distance-dependent, and interneuron-mediated circuits. With an appropriate degree of recurrent excitation and inhibition, spiking networks maintain a partially contrast-enhanced pattern for 800 milliseconds or longer after stimuli offset, then resolve to no stored pattern, or to winner-take-all stored patterns with one or multiple winners. Strengthening inhibition prolongs a partially contrast-enhanced pattern by slowing the transition to stability, while strengthening excitation causes more winners

  7. [Schizophrenia and cortical GABA neurotransmission].

    Science.gov (United States)

    Hashimoto, Takanori; Matsubara, Takuro; Lewis, David A

    2010-01-01

    -synaptic GABA-A receptors. Our recent analyses demonstrated that this pattern exists across diverse cortical areas including the prefrontal, anterior cingulate, primary motor, and primary visual cortices. GABA neurotransmission by PV-containing and SST-containing neurons is important for the generation of cortical oscillatory activities in the gamma (30-100 Hz) and theta (4-7 Hz) bands, respectively. These oscillatory activities have been proposed to play critical roles in regulating the efficiency of information transfer between neurons and neuronal networks in the cortex. Altered cortical GABA neurotransmission appears to contribute to disturbances in diverse functions through affecting the generation of cortical oscillations in schizophrenia.

  8. Implicit sequence-specific motor learning after sub-cortical stroke is associated with increased prefrontal brain activations: An fMRI study

    Science.gov (United States)

    Meehan, Sean K.; Randhawa, Bubblepreet; Wessel, Brenda; Boyd, Lara A.

    2010-01-01

    Implicit motor learning is preserved after stroke, but how the brain compensates for damage to facilitate learning is unclear. We used a random effects analysis to determine how stroke alters patterns of brain activity during implicit sequence-specific motor learning as compared to general improvements in motor control. Nine healthy participants and 9 individuals with chronic, right focal sub-cortical stroke performed a continuous joystick-based tracking task during an initial fMRI session, over 5 days of practice, and a retention test during a separate fMRI session. Sequence-specific implicit motor learning was differentiated from general improvements in motor control by comparing tracking performance on a novel, repeated tracking sequences during early practice and again at the retention test. Both groups demonstrated implicit sequence-specific motor learning at the retention test, yet substantial differences were apparent. At retention, healthy control participants demonstrated increased BOLD response in left dorsal premotor cortex (BA 6) but decreased BOLD response left dorsolateral prefrontal cortex (DLPFC; BA 9) during repeated sequence tracking. In contrast, at retention individuals with stroke did not show this reduction in DLPFC during repeated tracking. Instead implicit sequence-specific motor learning and general improvements in motor control were associated with increased BOLD response in the left middle frontal gyrus BA 8, regardless of sequence type after stroke. These data emphasize the potential importance of a prefrontal-based attentional network for implicit motor learning after stroke. The present study is the first to highlight the importance of the prefrontal cortex for implicit sequence-specific motor learning after stroke. PMID:20725908

  9. Cortical dynamics of visual change detection based on sensory memory.

    Science.gov (United States)

    Urakawa, Tomokazu; Inui, Koji; Yamashiro, Koya; Tanaka, Emi; Kakigi, Ryusuke

    2010-08-01

    Detecting a visual change was suggested to relate closely to the visual sensory memory formed by visual stimuli before the occurrence of the change, because change detection involves identifying a difference between ongoing and preceding sensory conditions. Previous neuroimaging studies showed that an abrupt visual change activates the middle occipital gyrus (MOG). However, it still remains to be elucidated whether the MOG is related to visual change detection based on sensory memory. Here we tried to settle this issue using a new method of stimulation with blue and red LEDs to emphasize a memory-based change detection process. There were two stimuli, a standard trial stimulus and a deviant trial stimulus. The former was a red light lasting 500 ms, and the latter was a red light lasting 250 ms immediately followed by a blue light lasting 250 ms. Effects of the trial-trial interval, 250 approximately 2000 ms, were investigated to know how cortical responses to the abrupt change (from red to blue) were affected by preceding conditions. The brain response to the deviant trial stimulus was recorded by magnetoencephalography. Results of a multi-dipole analysis showed that the activity in the MOG, peaking at around 150 ms after the change onset, decreased in amplitude as the interval increased, but the earlier activity in BA 17/18 was not affected by the interval. These results suggested that the MOG is an important cortical area relating to the sensory memory-based visual change-detecting system. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Similar PDK1-AKT-mTOR pathway activation in balloon cells and dysmorphic neurons of type II focal cortical dysplasia with refractory epilepsy.

    Science.gov (United States)

    Lin, Yuan-xiang; Lin, Kun; Kang, De-zhi; Liu, Xin-xiu; Wang, Xing-fu; Zheng, Shu-fa; Yu, Liang-hong; Lin, Zhang-ya

    2015-05-01

    Dysmorphic neurons and balloon cells constitute the neuropathological hallmarks of type II focal cortical dysplasias (FCDs) with refractory epilepsy. The genesis of these cells may be critical to the histological findings in type II FCD. Recent work has shown enhanced activation of the mTOR cascade in both balloon cells and dysmorphic neurons, suggesting a common pathogenesis for these two neuropathological hallmarks. A direct comparative analysis of balloon cells and dysmorphic neurons might identify a molecular link between balloon cells and dysmorphic neurons. Here, we addressed whether PDK1-AKT-mTOR activation differentiates balloon cells from dysmorphic neurons. We used immunohistochemistry with antibodies against phosphorylated (p)-PDK1 (Ser241), p-AKT (Thr308), p-AKT (Ser473), p-mTOR (Ser2448), p-P70S6K (Thr229), and p-p70S6 kinase (Thr389) in balloon cells compared with dysmorphic neurons. Strong or moderate staining for components of the PDK1-AKT-mTOR signaling pathway was observed in both balloon cells and dysmorphic neurons. However, only a few pyramidal neurons displayed weak staining in control group (perilesional neocortex and histologically normal neocortex). Additionally, p-PDK1 (Ser241) and p-AKT (Thr308) staining in balloon cells were stronger than in dysmorphic neurons, whereas p-P70S6K (Thr229) and p-p70S6 kinase (Thr389) staining in balloon cells was weaker than in dysmorphic neurons. In balloon cells, p-AKT (Ser473) and p-mTOR (Ser2448) staining was comparable with the staining in dysmorphic neurons. Our data support the previously suggested pathogenic relationship between balloon cells and dysmorphic neurons concerning activation of the PDK1-AKT-mTOR, which may play important roles in the pathogenesis of type II FCD. Differential expression of some components of the PDK1-AKT-mTOR pathway between balloon cells and dysmorphic neurons may result from cell-specific gene expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Dynamic Causal Modeling of the Cortical Responses to Wrist Perturbations

    Directory of Open Access Journals (Sweden)

    Yuan Yang

    2017-09-01

    Full Text Available Mechanical perturbations applied to the wrist joint typically evoke a stereotypical sequence of cortical and muscle responses. The early cortical responses (<100 ms are thought be involved in the “rapid” transcortical reaction to the perturbation while the late cortical responses (>100 ms are related to the “slow” transcortical reaction. Although previous studies indicated that both responses involve the primary motor cortex, it remains unclear if both responses are engaged by the same effective connectivity in the cortical network. To answer this question, we investigated the effective connectivity cortical network after a “ramp-and-hold” mechanical perturbation, in both the early (<100 ms and late (>100 ms periods, using dynamic causal modeling. Ramp-and-hold perturbations were applied to the wrist joint while the subject maintained an isometric wrist flexion. Cortical activity was recorded using a 128-channel electroencephalogram (EEG. We investigated how the perturbation modulated the effective connectivity for the early and late periods. Bayesian model comparisons suggested that different effective connectivity networks are engaged in these two periods. For the early period, we found that only a few cortico-cortical connections were modulated, while more complicated connectivity was identified in the cortical network during the late period with multiple modulated cortico-cortical connections. The limited early cortical network likely allows for a rapid muscle response without involving high-level cognitive processes, while the complexity of the late network may facilitate coordinated responses.

  12. Activity in a premotor cortical nucleus of zebra finches is locally organized and exhibits auditory selectivity in neurons but not in glia.

    Directory of Open Access Journals (Sweden)

    Michael H Graber

    Full Text Available Motor functions are often guided by sensory experience, most convincingly illustrated by complex learned behaviors. Key to sensory guidance in motor areas may be the structural and functional organization of sensory inputs and their evoked responses. We study sensory responses in large populations of neurons and neuron-assistive cells in the songbird motor area HVC, an auditory-vocal brain area involved in sensory learning and in adult song production. HVC spike responses to auditory stimulation display remarkable preference for the bird's own song (BOS compared to other stimuli. Using two-photon calcium imaging in anesthetized zebra finches we measure the spatio-temporal structure of baseline activity and of auditory evoked responses in identified populations of HVC cells. We find strong correlations between calcium signal fluctuations in nearby cells of a given type, both in identified neurons and in astroglia. In identified HVC neurons only, auditory stimulation decorrelates ongoing calcium signals, less for BOS than for other sound stimuli. Overall, calcium transients show strong preference for BOS in identified HVC neurons but not in astroglia, showing diversity in local functional organization among identified neuron and astroglia populations.

  13. Differences in cortical and pituitary activity in response to hypoglycaemia and cognitive testing in healthy men with different basal activity of the renin-angiotensin system

    DEFF Research Database (Denmark)

    Bie-Olsen, Lise G; Pedersen-Bjergaard, Ulrik; Kjaer, Troels W

    2010-01-01

    in cerebral activity during hypoglycaemia and cognitive testing in two groups of healthy men with different basal RAS activity. METHODS: Ten healthy men with high RAS activity and 10 with low activity underwent six oxygen-15-labelled water positron emission tomography scans: twice during normoglycaemia, twice......INTRODUCTION: High renin-angiotensin system (RAS) activity has been associated with a high risk of severe hypoglycaemia in patients with type 1 diabetes and with cognitive deterioration during experimental hypoglycaemia in healthy subjects. The aim of this study was to describe possible differences...... during insulin-induced hypoglycaemia and twice during post-hypoglycaemia. During the scans, the subjects performed a computer-based reaction time test. RESULTS: Occipital areas were consistently more activated in the low RAS group than in the high RAS group throughout all three conditions. During...

  14. Short-term memory in networks of dissociated cortical neurons.

    Science.gov (United States)

    Dranias, Mark R; Ju, Han; Rajaram, Ezhilarasan; VanDongen, Antonius M J

    2013-01-30

    Short-term memory refers to the ability to store small amounts of stimulus-specific information for a short period of time. It is supported by both fading and hidden memory processes. Fading memory relies on recurrent activity patterns in a neuronal network, whereas hidden memory is encoded using synaptic mechanisms, such as facilitation, which persist even when neurons fall silent. We have used a novel computational and optogenetic approach to investigate whether these same memory processes hypothesized to support pattern recognition and short-term memory in vivo, exist in vitro. Electrophysiological activity was recorded from primary cultures of dissociated rat cortical neurons plated on multielectrode arrays. Cultures were transfected with ChannelRhodopsin-2 and optically stimulated using random dot stimuli. The pattern of neuronal activity resulting from this stimulation was analyzed using classification algorithms that enabled the identification of stimulus-specific memories. Fading memories for different stimuli, encoded in ongoing neural activity, persisted and could be distinguished from each other for as long as 1 s after stimulation was terminated. Hidden memories were detected by altered responses of neurons to additional stimulation, and this effect persisted longer than 1 s. Interestingly, network bursts seem to eliminate hidden memories. These results are similar to those that have been reported from similar experiments in vivo and demonstrate that mechanisms of information processing and short-term memory can be studied using cultured neuronal networks, thereby setting the stage for therapeutic applications using this platform.

  15. Insulin and IGF-1 activate Kir4.1/5.1 channels in cortical collecting duct principal cells to control basolateral membrane voltage.

    Science.gov (United States)

    Zaika, Oleg; Palygin, Oleg; Tomilin, Viktor; Mamenko, Mykola; Staruschenko, Alexander; Pochynyuk, Oleh

    2016-02-15

    Potassium Kir4.1/5.1 channels are abundantly expressed at the basolateral membrane of principal cells in the cortical collecting duct (CCD), where they are thought to modulate transport rates by controlling transepithelial voltage. Insulin and insulin-like growth factor-1 (IGF-1) stimulate apically localized epithelial sodium channels (ENaC) to augment sodium reabsorption in the CCD. However, little is known about their actions on potassium channels localized at the basolateral membrane. In this study, we implemented patch-clamp analysis in freshly isolated murine CCD to assess the effect of these hormones on Kir4.1/5.1 at both single channel and cellular levels. We demonstrated that K(+)-selective conductance via Kir4.1/5.1 is the major contributor to the macroscopic current recorded from the basolateral side in principal cells. Acute treatment with 10 μM amiloride (ENaC blocker), 100 nM tertiapin-Q (TPNQ; ROMK inhibitor), and 100 μM ouabain (Na(+)-K(+)-ATPase blocker) failed to produce a measurable effect on the macroscopic current. In contrast, Kir4.1 inhibitor nortriptyline (100 μM), but not fluoxetine (100 μM), virtually abolished whole cell K(+)-selective conductance. Insulin (100 nM) markedly increased the open probability of Kir4.1/5.1 and nortriptyline-sensitive whole cell current, leading to significant hyperpolarization of the basolateral membrane. Inhibition of the phosphatidylinositol 3-kinase cascade with LY294002 (20 μM) abolished action of insulin on Kir4.1/5.1. IGF-1 had similar stimulatory actions on Kir4.1/5.1-mediated conductance only when applied at a higher (500 nM) concentration and was ineffective at 100 nM. We concluded that both insulin and, to a lesser extent, IGF-1 activate Kir4.1/5.1 channel activity and open probability to hyperpolarize the basolateral membrane, thereby facilitating Na(+) reabsorption in the CCD. Copyright © 2016 the American Physiological Society.

  16. Early and phasic cortical metabolic changes in vestibular neuritis onset.

    Directory of Open Access Journals (Sweden)

    Marco Alessandrini

    Full Text Available Functional brain activation studies described the presence of separate cortical areas responsible for central processing of peripheral vestibular information and reported their activation and interactions with other sensory modalities and the changes of this network associated to strategic peripheral or central vestibular lesions. It is already known that cortical changes induced by acute unilateral vestibular failure (UVF are various and undergo variations over time, revealing different cortical involved areas at the onset and recovery from symptoms. The present study aimed at reporting the earliest change in cortical metabolic activity during a paradigmatic form of UVF such as vestibular neuritis (VN, that is, a purely peripheral lesion of the vestibular system, that offers the opportunity to study the cortical response to altered vestibular processing. This research reports [(18F]fluorodeoxyglucose positron emission tomography brain scan data concerning the early cortical metabolic activity associated to symptoms onset in a group of eight patients suffering from VN. VN patients' cortical metabolic activity during the first two days from symptoms onset was compared to that recorded one month later and to a control healthy group. Beside the known cortical response in the sensorimotor network associated to vestibular deafferentation, we show for the first time the involvement of Entorhinal (BAs 28, 34 and Temporal (BA 38 cortices in early phases of symptomatology onset. We interpret these findings as the cortical counterparts of the attempt to reorient oneself in space counteracting the vertigo symptom (Bas 28, 34 and of the emotional response to the new pathologic condition (BA 38 respectively. These interpretations were further supported by changes in patients' subjective ratings in balance, anxiety, and depersonalization/derealization scores when tested at illness onset and one month later. The present findings contribute in expanding

  17. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, MAJ; Thom, M; Ellison, DW; Wilkins, P; Barnes, D; Thompson, PD; Brown, P

    2000-01-01

    Objective To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. Background: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  18. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, M. A.; Thom, M.; Ellison, D. W.; Wilkins, P.; Barnes, D.; Thompson, P. D.; Brown, P.

    2000-01-01

    OBJECTIVE: To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. BACKGROUND: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  19. Universal patterns underlying ongoing wars and terrorism

    OpenAIRE

    Spagat, M; Johnson, N. F; Restrepo, J. A; Becerra, O; Bohórquez, J. C; Restrepo, E. M; Zarama, R

    2006-01-01

    we report a remarkable universality in the patterns of violence in three high profile ongoing wars, and in global terrorism. Our results suggest that these quite different conflict arenas currently feature a common type of enemy, i.e. the various insurgent forces are beginning to operate in a similar way regardles of their underlying idealogies, motivations and the terrain in which they operate. We provide a microscopic theory to explain our main observations. This theory treats the insurgent...

  20. Differences in cortical and pituitary activity in response to hypoglycaemia and cognitive testing in healthy men with different basal activity of the renin-angiotensin system

    DEFF Research Database (Denmark)

    Bie-Olsen, Lise G; Pedersen-Bjergaard, Ulrik; Kjaer, Troels W

    2010-01-01

    INTRODUCTION: High renin-angiotensin system (RAS) activity has been associated with a high risk of severe hypoglycaemia in patients with type 1 diabetes and with cognitive deterioration during experimental hypoglycaemia in healthy subjects. The aim of this study was to describe possible differenc...

  1. The relationship between level of processing and hippocampal-cortical functional connectivity during episodic memory formation in humans.

    Science.gov (United States)

    Schott, Björn H; Wüstenberg, Torsten; Wimber, Maria; Fenker, Daniela B; Zierhut, Kathrin C; Seidenbecher, Constanze I; Heinze, Hans-Jochen; Walter, Henrik; Düzel, Emrah; Richardson-Klavehn, Alan

    2013-02-01

    New episodic memory traces represent a record of the ongoing neocortical processing engaged during memory formation (encoding). Thus, during encoding, deep (semantic) processing typically establishes more distinctive and retrievable memory traces than does shallow (perceptual) processing, as assessed by later episodic memory tests. By contrast, the hippocampus appears to play a processing-independent role in encoding, because hippocampal lesions impair encoding regardless of level of processing. Here, we clarified the neural relationship between processing and encoding by examining hippocampal-cortical connectivity during deep and shallow encoding. Participants studied words during functional magnetic resonance imaging and freely recalled these words after distraction. Deep study processing led to better recall than shallow study processing. For both levels of processing, successful encoding elicited activations of bilateral hippocampus and left prefrontal cortex, and increased functional connectivity between left hippocampus and bilateral medial prefrontal, cingulate and extrastriate cortices. Successful encoding during deep processing was additionally associated with increased functional connectivity between left hippocampus and bilateral ventrolateral prefrontal cortex and right temporoparietal junction. In the shallow encoding condition, on the other hand, pronounced functional connectivity increases were observed between the right hippocampus and the frontoparietal attention network activated during shallow study processing. Our results further specify how the hippocampus coordinates recording of ongoing neocortical activity into long-term memory, and begin to provide a neural explanation for the typical advantage of deep over shallow study processing for later episodic memory. Copyright © 2011 Wiley Periodicals, Inc.

  2. Possible involvement of integrin-mediated signalling in oocyte activation: evidence that a cyclic RGD-containing peptide can stimulate protein kinase C and cortical granule exocytosis in mouse oocytes

    Directory of Open Access Journals (Sweden)

    Carbone Maria

    2006-09-01

    Full Text Available Abstract Background Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development in amphibian and bovine oocytes. In the present study, we investigate the hypothesis that an integrin-associated signalling may participate in oocyte activation signalling by determining the ability of a cyclic RGD-containing peptide to stimulate the activation of protein kinase C (PKC and the exocytosis of cortical granules in mouse oocytes. Methods An In-Vitro-Fertilization assay (IVF was carried in order to test the condition under which a peptide containing the RGD sequence, cyclo(Arg-Gly-Asp-D-Phe-Val, was able to inhibit sperm fusion with zona-free mouse oocytes at metaphase II stage. PKC activity was determined by means of an assay based on the ability of cell lysates to phosphorylate MARKS peptide, a specific PKC substrate. Loss of cortical granules was evaluated by measuring density in the oocyte cortex of cortical granules stained with LCA-biotin/Texas red-streptavidin. In all the experiments, effects of a control peptide containing a non RGD sequence, cyclo(Arg-Ala-Asp-D-Phe-Val, were evaluated. Results The IVF assay revealed that the fusion rate declined significantly when insemination was carried out in the presence of cyclic RGD peptide at concentrations > or = 250 microM (P Conclusion The presents results provide evidence that a cyclic RGD peptide highly effective in inhibiting sperm-oocyte interaction stimulates in mouse oocytes the activation of PKC and the exocytosis of cortical granules. These data support the view that RGD-binding receptors may function as signalling receptors giving rise integrated signalling not sufficient for

  3. Optic issues in ongoing ERL projects

    International Nuclear Information System (INIS)

    Smith, S.L.; Muratori, B.D.; Owen, H.L.; Hoffstaetter, G.H.; Litvinenko, V.N.; Ben-Zvi, I.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Calaga, R.; Fischer, W.; Chang, X.Y.; Kayran, D.; Kewisch, J.; MacKay, W.W.; Montag, C.; Parker, B.; Ptitsyn, V.; Roser, T.; Ruggiero, A.; Satogata, T.; Surrow, B.; Tepikian, S.; Trbojevic, D.; Yakimenko, V.; Zhang, S.Y.; Piot, Ph.

    2006-01-01

    A wide range of optics issues for energy recovery linac (ERL)-based projects are illustrated through the presentation of ongoing projects covering both light sources, at Cornell and Daresbury and high energy and nuclear physics accelerators at the Brookhaven National Laboratory. This presented range of projects demonstrates how the different designs teams see the challenges of studying and solving optics issues for their particular project's ERLs, with studies appropriate to the stage of maturity of the project. Finally, as an illustration of the complexity and detail behind a single aspect of ERL optics design we present an overview of the highly important generic topic of longitudinal phase space evolution in ERLs

  4. Eye-movements and ongoing task processing.

    Science.gov (United States)

    Burke, David T; Meleger, Alec; Schneider, Jeffrey C; Snyder, Jim; Dorvlo, Atsu S S; Al-Adawi, Samir

    2003-06-01

    This study tests the relation between eye-movements and thought processing. Subjects were given specific modality tasks (visual, gustatory, kinesthetic) and assessed on whether they responded with distinct eye-movements. Some subjects' eye-movements reflected ongoing thought processing. Instead of a universal pattern, as suggested by the neurolinguistic programming hypothesis, this study yielded subject-specific idiosyncratic eye-movements across all modalities. Included is a discussion of the neurolinguistic programming hypothesis regarding eye-movements and its implications for the eye-movement desensitization and reprocessing theory.

  5. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    Directory of Open Access Journals (Sweden)

    Dylan eBarnes

    2014-04-01

    Full Text Available In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders.

  6. Relating Cortical Wave Dynamics to Learning and Remembering

    Directory of Open Access Journals (Sweden)

    Eduardo Mercado III

    2014-12-01

    Full Text Available Electrical waves propagate across sensory and motor cortices in stereotypical patterns. These waves have been described as potentially facilitating sensory processing when they travel through sensory cortex, as guiding movement preparation and performance when they travel across motor cortex, and as possibly promoting synaptic plasticity and the consolidation of memory traces, especially during sleep. Here, an alternative theoretical framework is suggested that integrates Pavlovian hypotheses about learning and cortical function with concepts from contemporary proceduralist theories of memory. The proposed framework postulates that sensory-evoked cortical waves are gradually modified across repeated experiences such that the waves more effectively differentiate sensory events, and so that the waves are more likely to reverberate. It is argued that the qualities of cortical waves—their origins, form, intensity, speed, periodicity, extent, and trajectories —are a function of both the structural organization of neural circuits and ongoing reverberations resulting from previously experienced events. It is hypothesized that experience-dependent cortical plasticity, both in the short- and long-term, modulates the qualities of cortical waves, thereby enabling individuals to make progressively more precise distinctions between complex sensory events, and to reconstruct components of previously experienced events. Unlike most current neurobiological theories of learning and memory mechanisms, this hypothesis does not assume that synaptic plasticity, or any other form of neural plasticity, serves to store physical records of previously experienced events for later reactivation. Rather, the reorganization of cortical circuits may alter the potential for certain wave patterns to arise and persist. Understanding what factors determine the spatiotemporal dynamics of cortical waves, how structural changes affect their qualities, and how wave dynamics

  7. Successful ongoing pregnancies after vitrification of oocytes.

    Science.gov (United States)

    Lucena, Elkin; Bernal, Diana Patricia; Lucena, Carolina; Rojas, Alejandro; Moran, Abby; Lucena, Andrés

    2006-01-01

    To demonstrate the efficiency of vitrifying mature human oocytes for different clinical indications. Descriptive case series. Cryobiology laboratory, Centro Colombiano de Fertilidad y Esterilidad-CECOLFES LTDA. (Bogotá, Colombia). Oocyte vitrification was offered as an alternative management for patients undergoing infertility treatment because of ovarian hyperstimulation syndrome, premature ovarian failure, natural ovarian failure, male factor, poor response, or oocyte donation. Mature oocytes were obtained from 33 donor women and 40 patients undergoing infertility treatment. Oocytes were retrieved by ultrasound-guided transvaginal aspiration and vitrified with the Cryotops method, with 30% ethylene glycol, 30% dimethyl sulfoxide, and 0.5 mol/L sucrose. Viability was assessed 3 hours after thawing. The surviving oocytes were inseminated by intracytoplasmic sperm injection. Fertilization was evaluated after 24 hours. The zygotes were further cultured in vitro for up to 72 hours until time of embryo transfer. Recovery, viability, fertilization, and pregnancy rates. Oocyte vitrification with the Cryotop method resulted in high rates of recovery, viability, fertilization, cleavage, and ongoing pregnancy. Vitrification with the Cryotop method is an efficient, fast, and economical method for oocyte cryopreservation that offers high rates of survival, fertilization, embryo development, and ongoing normal pregnancies, providing a new alternative for the management of female infertility.

  8. Ongoing Model Development Analyzing Glass Fracture

    DEFF Research Database (Denmark)

    Molnar, G.; Bojtar, I.; Nielsen, Jens Henrik

    2013-01-01

    Present subject deals with an ongoing experimental and numerical analysis of inplane loaded glass plates. The main goal of the investigation is to develop a hybrid – discrete and finite element – model which could follow the fracture process in annealed and in tempered glass. Measurements of the ...... an overview of the structure of the research and a summary of current status archived so far.......Present subject deals with an ongoing experimental and numerical analysis of inplane loaded glass plates. The main goal of the investigation is to develop a hybrid – discrete and finite element – model which could follow the fracture process in annealed and in tempered glass. Measurements...... of the residual stress state before failure and high-speed camera recordings of the failure are being performed in order to verify the numerical model. The primary goal of this research is to follow the overall fracture of a structural element – e.g. beam – loaded inplane. Present paper would like to give...

  9. The enemy within: propagation of aberrant corticostriatal learning to cortical function in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Jeff A Beeler

    2013-09-01

    Full Text Available Motor dysfunction in Parkinson’s disease is believed to arise primarily from pathophysiology in the dorsal striatum and its related corticostriatal and thalamostriatal circuits during progressive dopamine denervation. One function of these circuits is to provide a filter that selectively facilitates or inhibits cortical activity to optimize cortical processing, making motor responses rapid and efficient. Corticostriatal synaptic plasticity mediates the learning that underlies this performance-optimizing filter. Under dopamine denervation, corticostriatal plasticity is altered, resulting in aberrant learning that induces inappropriate basal ganglia filtering that impedes rather than optimizes cortical processing. Human imaging suggests that increased cortical activity may compensate for striatal dysfunction in PD patients. In this Perspective article, we consider how aberrant learning at corticostriatal synapses may impair cortical processing and learning and undermine potential cortical compensatory mechanisms. Blocking or remediating aberrant corticostriatal plasticity may protect cortical function and support cortical compensatory mechanisms mitigating the functional decline associated with progressive dopamine denervation.

  10. Enhancement of cortical network activity in vitro and promotion of GABAergic neurogenesis by stimulation with an electromagnetic field with a 150 MHz carrier wave pulsed with an alternating 10 and 16 Hz modulation.

    Directory of Open Access Journals (Sweden)

    Alexandra eGramowski-Voss

    2015-07-01

    Full Text Available In recent years, various stimuli were identified capable of enhancing neurogenesis, a process which is dysfunctional in the senescent brain and in neurodegenerative and certain neuropsychiatric diseases. Applications of electromagnetic fields to brain tissue have been shown to affect cellular properties and their importance for therapies in medicine is recognized.In this study, differentiating murine cortical networks on multiwell microelectrode arrays were repeatedly exposed to an extremely low electromagnetic field (ELEMF with alternating 10 and 16 Hz frequencies piggy-backed onto a 150 MHz carrier frequency. The ELEMF exposure stimulated the electrical network activity and intensified the structure of bursts. Further, the exposure with an electromagnetic field within the first 28 days of the differentiation the network activity induced also reorganization within the burst structure. This effect was already most pronounced at 14 days in vitro after 10 days of exposure. Overall, the development of cortical activity under these conditions was accelerated. These functional electrophysiological changes were accompanied by morphological ones. The percentage of neurons in the neuron glia co-culture was increased without affecting the total number of cells, indicating an enhancement of neurogenesis. The ELEMF exposure selectively promoted the proliferation of a particular population of neurons, evidenced by the increased proportion of GABAergic neurons. The results support the initial hypothesis that this kind of ELEMF stimulation is a treatment option for specific indications with promising potential for CNS applications, especially for degenerative diseases such as Alzheimer’s disease and other dementias.

  11. A Mechanistic Link from GABA to Cortical Architecture and Perception.

    Science.gov (United States)

    Kolasinski, James; Logan, John P; Hinson, Emily L; Manners, Daniel; Divanbeighi Zand, Amir P; Makin, Tamar R; Emir, Uzay E; Stagg, Charlotte J

    2017-06-05

    Understanding both the organization of the human cortex and its relation to the performance of distinct functions is fundamental in neuroscience. The primary sensory cortices display topographic organization, whereby receptive fields follow a characteristic pattern, from tonotopy to retinotopy to somatotopy [1]. GABAergic signaling is vital to the maintenance of cortical receptive fields [2]; however, it is unclear how this fine-grain inhibition relates to measurable patterns of perception [3, 4]. Based on perceptual changes following perturbation of the GABAergic system, it is conceivable that the resting level of cortical GABAergic tone directly relates to the spatial specificity of activation in response to a given input [5-7]. The specificity of cortical activation can be considered in terms of cortical tuning: greater cortical tuning yields more localized recruitment of cortical territory in response to a given input. We applied a combination of fMRI, MR spectroscopy, and psychophysics to substantiate the link between the cortical neurochemical milieu, the tuning of cortical activity, and variability in perceptual acuity, using human somatosensory cortex as a model. We provide data that explain human perceptual acuity in terms of both the underlying cellular and metabolic processes. Specifically, higher concentrations of sensorimotor GABA are associated with more selective cortical tuning, which in turn is associated with enhanced perception. These results show anatomical and neurochemical specificity and are replicated in an independent cohort. The mechanistic link from neurochemistry to perception provides a vital step in understanding population variability in sensory behavior, informing metabolic therapeutic interventions to restore perceptual abilities clinically. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  12. Massive cortical reorganization in sighted Braille readers.

    Science.gov (United States)

    Siuda-Krzywicka, Katarzyna; Bola, Łukasz; Paplińska, Małgorzata; Sumera, Ewa; Jednoróg, Katarzyna; Marchewka, Artur; Śliwińska, Magdalena W; Amedi, Amir; Szwed, Marcin

    2016-03-15

    The brain is capable of large-scale reorganization in blindness or after massive injury. Such reorganization crosses the division into separate sensory cortices (visual, somatosensory...). As its result, the visual cortex of the blind becomes active during tactile Braille reading. Although the possibility of such reorganization in the normal, adult brain has been raised, definitive evidence has been lacking. Here, we demonstrate such extensive reorganization in normal, sighted adults who learned Braille while their brain activity was investigated with fMRI and transcranial magnetic stimulation (TMS). Subjects showed enhanced activity for tactile reading in the visual cortex, including the visual word form area (VWFA) that was modulated by their Braille reading speed and strengthened resting-state connectivity between visual and somatosensory cortices. Moreover, TMS disruption of VWFA activity decreased their tactile reading accuracy. Our results indicate that large-scale reorganization is a viable mechanism recruited when learning complex skills.

  13. Stroke rehabilitation using noninvasive cortical stimulation: aphasia.

    Science.gov (United States)

    Mylius, Veit; Zouari, Hela G; Ayache, Samar S; Farhat, Wassim H; Lefaucheur, Jean-Pascal

    2012-08-01

    Poststroke aphasia results from the lesion of cortical areas involved in the motor production of speech (Broca's aphasia) or in the semantic aspects of language comprehension (Wernicke's aphasia). Such lesions produce an important reorganization of speech/language-specific brain networks due to an imbalance between cortical facilitation and inhibition. In fact, functional recovery is associated with changes in the excitability of the damaged neural structures and their connections. Two main mechanisms are involved in poststroke aphasia recovery: the recruitment of perilesional regions of the left hemisphere in case of small lesion and the acquisition of language processing ability in homotopic areas of the nondominant right hemisphere when left hemispheric language abilities are permanently lost. There is some evidence that noninvasive cortical stimulation, especially when combined with language therapy or other therapeutic approaches, can promote aphasia recovery. Cortical stimulation was mainly used to either increase perilesional excitability or reduce contralesional activity based on the concept of reciprocal inhibition and maladaptive plasticity. However, recent studies also showed some positive effects of the reinforcement of neural activities in the contralateral right hemisphere, based on the potential compensatory role of the nondominant hemisphere in stroke recovery.

  14. Update of the ongoing comparison BIPM.RI(II)-K1.Se-75 to include recent activity measurements of the radionuclide {sup 75}Se by the LNE-LNHB (France)

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Courte, S.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, F-92312 Sevres cedex (France); Moune, M.; Bobin, C. [Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel (LNE-LNHB), Gif-sur-Yvette Cedex (France)

    2011-06-15

    In 2006, to update their previous result of 1992, the LNE-LNHB submitted a new sample of {sup 75}Se with an activity of about 2.2 MBq to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). This comparison has the identifier BIPM.RI(II)-K1.Se-75. The degree of equivalence between the equivalent activity measured in the SIR for the new LNE-LNHB sample and the updated key comparison reference value (KCRV) has been calculated, as have the degrees of equivalence with each of the other participants. The results are given in the form of a matrix and a graphical presentation is also given. (authors)

  15. Are the Symptoms of Parkinsonism Cortical in Origin?

    Directory of Open Access Journals (Sweden)

    Gordon W. Arbuthnott

    Full Text Available We present three reasons to suspect that the major deleterious consequence of dopamine loss from the striatum is a cortical malfunction. We suggest that it is cortex, rather than striatum, that should be considered as the source of the debilitating symptoms of Parkinson's disease (PD since: 1. Cortical synapses onto striatal dendritic spines are lost in PD. 2. All known treatments of the symptoms of PD disrupt beta oscillations. Oscillations that are also disrupted following antidromic activation of cortical neurons. 3. The final output of basal ganglia directly modulates thalamic connections to layer I of frontal cortical areas, regions intimately associated with motor behaviour.These three reasons combined with evidence that the current summary diagram of the basal ganglia involvement in PD is imprecise at best, suggest that a re-orientation of the treatment strategies towards cortical, rather than striatal malfunction, is overdue. Keywords: Parkinson's disease, Deep brain stimulation, Layer I, Motor cortex

  16. Depletion of rat cortical norepinephrine and the inhibition of [3H]norepinephrine uptake by xylamine does not require monoamine oxidase activity

    International Nuclear Information System (INIS)

    Dudley, M.W.

    1988-01-01

    Inhibition of monoamine oxidase A through pretreatment of rats with clorgyline or the pro-drug MDL 72,394 did not block the amine-depleting action of xylamine. Xylamine treatment resulted in a loss of approximately 60% of the control level of norepinephrine in the cerebral cortex. A 1-hr pretreatment, but not a 24-hr pretreatment, with the monoamine oxidase B inhibitor, L-deprenyl, prevented the depletion of norepinephrine by xylamine. In addition, pretreatment with MDL 72,974, a monoamine oxidase B inhibitor without amine-releasing or uptake - inhibiting effects, did not prevent cortical norepinephrine levels. Inhibition of monoamine oxidase by either MDL 72,974 or MDL 72,394 did not prevent the inhibition of [ 3 H]norepinephrine uptake into rat cortical synaptosomes by xylamine. These data indicate that monoamine oxidase does not mediate the amine-releasing or uptake inhibiting properties of xylamine. The protection afforded by L-deprenyl following a 1-hr pretreatment most probably was due to accumulation of its metabolite, L-amphetamine, which would inhibit the uptake carrier. A functional carrier is required for depletion since desipramine administered 1 hr prior to xylamine, was also able to prevent depletion of norepinephrine

  17. Cortical inactivation by cooling in small animals

    Directory of Open Access Journals (Sweden)

    Ben eCoomber

    2011-06-01

    Full Text Available Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently there has been a concern that the cryoloop may also cool non-cortical structures either directly or via the perfusion of blood, cooled as it passed close to the cooling loop. In this study we have confirmed that the loop can inactivate most of the auditory cortex without causing a significant reduction in temperature of the auditory thalamus or other sub-cortical structures. We placed a cryoloop on the surface of the guinea pig cortex, cooled it to 2°C and measured thermal gradients across the neocortical surface. We found that the temperature dropped to 20-24°C among cells within a radius of about 2.5mm away from the loop. This temperature drop was sufficient to reduce activity of most cortical cells and led to the inactivation of almost the entire auditory region. When the temperature of thalamus, midbrain, and middle ear were measured directly during cortical cooling, there was a small drop in temperature (about 4°C but this was not sufficient to directly reduce neural activity. In an effort to visualise the extent of neural inactivation we measured the uptake of thallium ions following an intravenous injection. This confirmed that there was a large reduction of activity across much of the ipsilateral cortex and only a small reduction in subcortical structures.

  18. Increased Cortical Thickness in Professional On-Line Gamers

    Science.gov (United States)

    Hyun, Gi Jung; Shin, Yong Wook; Kim, Bung-Nyun; Cheong, Jae Hoon; Jin, Seong Nam

    2013-01-01

    Objective The bulk of recent studies have tested whether video games change the brain in terms of activity and cortical volume. However, such studies are limited by several factors including cross-sectional comparisons, co-morbidity, and short-term follow-up periods. In the present study, we hypothesized that cognitive flexibility and the volume of brain cortex would be correlated with the career length of on-line pro-gamers. Methods High-resolution magnetic resonance scans were acquired in twenty-three pro-gamers recruited from StarCraft pro-game teams. We measured cortical thickness in each individual using FreeSurfer and the cortical thickness was correlated with the career length and the performance of the pro-gamers. Results Career length was positively correlated with cortical thickness in three brain regions: right superior frontal gyrus, right superior parietal gyrus, and right precentral gyrus. Additionally, increased cortical thickness in the prefrontal cortex was correlated with winning rates of the pro-game league. Increased cortical thickness in the prefrontal and parietal cortices was also associated with higher performance of Wisconsin Card Sorting Test. Conclusion Our results suggest that in individuals without pathologic conditions, regular, long-term playing of on-line games is associated with volume changes in the prefrontal and parietal cortices, which are associated with cognitive flexibility. PMID:24474988

  19. Activity measurements of the radionuclide {sup 57}Co for the NMIJ, Japan and the LNE-LNHB, France in the ongoing comparison BIPM.RI(II)-K1.Co-57

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Ratel, G.; Courte, S. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Hino, Y.; Yunoki, A. [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Bobin, C.; Moune, M. [CEA Saclay, Laboratoire National de Metrologie et d' Essais, Laboratoire National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France)

    2009-04-15

    In 2006 and 2007, the National Metrology Institute of Japan (NMIJ) and the Laboratoire national de metrologie et d'essais-Laboratoire national Henri Becquerel (LNE-LNHB) submitted samples of known activity of {sup 57}Co to the International Reference System (SIR). The values of the activity submitted were about 1.7 MBq and 3.7 MBq respectively. The new key comparison results have replaced the previous results for Japan and France. These new results have enabled a re-evaluation of the key comparison reference value. The matrix of degrees of equivalence in the key comparison database that now contains twelve results, identifier BIPM.RI(II)-K1.Co-57, has been updated with the new results. (authors)

  20. Order-based representation in random networks of cortical neurons.

    Directory of Open Access Journals (Sweden)

    Goded Shahaf

    2008-11-01

    Full Text Available The wide range of time scales involved in neural excitability and synaptic transmission might lead to ongoing change in the temporal structure of responses to recurring stimulus presentations on a trial-to-trial basis. This is probably the most severe biophysical constraint on putative time-based primitives of stimulus representation in neuronal networks. Here we show that in spontaneously developing large-scale random networks of cortical neurons in vitro the order in which neurons are recruited following each stimulus is a naturally emerging representation primitive that is invariant to significant temporal changes in spike times. With a relatively small number of randomly sampled neurons, the information about stimulus position is fully retrievable from the recruitment order. The effective connectivity that makes order-based representation invariant to time warping is characterized by the existence of stations through which activity is required to pass in order to propagate further into the network. This study uncovers a simple invariant in a noisy biological network in vitro; its applicability under in vivo constraints remains to be seen.

  1. Cortical spreading depression in migraine-time to reconsider?

    Directory of Open Access Journals (Sweden)

    Alan J McComas

    2015-08-01

    Full Text Available New evidence concerning the pathophysiology of migraine has come from the results of therapeutic transcranial magnetic stimulation (tTMS. The instantaneous responses to single pulses applied during the aura or headache phase, together with a number of other observations, make it unlikely that cortical spreading depression is involved in migraine. tTMS is considered to act by abolishing abnormal impulse activity in cortical pyramidal neurons and a suggestion is made as to how this activity could arise.

  2. Functional cortical mapping of scale illusion

    International Nuclear Information System (INIS)

    Wang, Li-qun; Kuriki, Shinya

    2011-01-01

    We have studied cortical activation using 1.5 T fMRI during 'Scale Illusion', a kind of auditory illusion, in which subjects perceive smooth melodies while listening to dichotic irregular pitch sequences consisting of scale tones, in repeated phrases composed of eight tones. Four male and four female subjects listened to different stimuli, that including illusion-inducing tone sequence, monaural tone sequence and perceived pitch sequence with a control of white noises delivered to the right and left ears in random order. 32 scans with a repetition time (TR) 3 s Between 3 s interval for each type of the four stimuli were performed. In BOLD signals, activation was observed in the prefrontal and temporal cortices, parietal lobule and occipital areas by first-level group analysis. However, there existed large intersubject variability such that systematic tendency of the activation was not clear. The study will be continued to obtain larger number of subjects for group analysis. (author)

  3. Adaptation to Cortical Noise Induced by Transcranial Magnetic Stimulation to the Occipital Lobe

    Directory of Open Access Journals (Sweden)

    David Heslip

    2012-05-01

    Full Text Available Transcranial magnetic stimulation (TMS is increasingly used as a method to modify and study functional brain activity. However, results from various studies have produced conflicting theories on how TMS of cortical tissue influences ongoing visual processing. To investigate this issue, single pulse TMS was applied over left V1 in five healthy subjects during an orientation discrimination task (vertical vs. horizontal using a Gabor patch (2 c/deg, presented 6° in the right visual field. Stimulus contrast was set to each individual's threshold, measured in the absence of TMS. When TMS was applied over V1 performance decreased in all observers (by 1.2–8.7% compared to accuracy levels obtained during stimulation of a control site (Cz. Crucially, accuracy levels during V1 stimulation gradually improved across blocks of 200 trials in some subjects, whereas performance remained stable during control site stimulation. In contrast, this pattern of recovery was not found in an analogous backward masking paradigm, using a brief visual noise mask instead of a TMS pulse. These results show that that the magnitude of TMS disruption can dissipate with repeated stimulation. This suggests that future studies using this technique should minimise the length of TMS exposure within each session to maximise its effectiveness. Our results show that the visual system can adapt dynamically to increased internal noise levels, minimising the impact of TMS induced cortical activity on sensory judgments.

  4. Computational modeling of epidural cortical stimulation

    Science.gov (United States)

    Wongsarnpigoon, Amorn; Grill, Warren M.

    2008-12-01

    Epidural cortical stimulation (ECS) is a developing therapy to treat neurological disorders. However, it is not clear how the cortical anatomy or the polarity and position of the electrode affects current flow and neural activation in the cortex. We developed a 3D computational model simulating ECS over the precentral gyrus. With the electrode placed directly above the gyrus, about half of the stimulus current flowed through the crown of the gyrus while current density was low along the banks deep in the sulci. Beneath the electrode, neurons oriented perpendicular to the cortical surface were depolarized by anodic stimulation, and neurons oriented parallel to the boundary were depolarized by cathodic stimulation. Activation was localized to the crown of the gyrus, and neurons on the banks deep in the sulci were not polarized. During regulated voltage stimulation, the magnitude of the activating function was inversely proportional to the thickness of the CSF and dura. During regulated current stimulation, the activating function was not sensitive to the thickness of the dura but was slightly more sensitive than during regulated voltage stimulation to the thickness of the CSF. Varying the width of the gyrus and the position of the electrode altered the distribution of the activating function due to changes in the orientation of the neurons beneath the electrode. Bipolar stimulation, although often used in clinical practice, reduced spatial selectivity as well as selectivity for neuron orientation.

  5. "We must cooperate with one another against the Enemy": Agency and activism in school-aged children as protective factors against ongoing war trauma and political violence in the Gaza Strip.

    Science.gov (United States)

    Veronese, Guido; Pepe, Alessandro; Jaradah, Alaa; Murannak, Feda; Hamdouna, Housam

    2017-08-01

    This exploratory qualitative study investigated self-perceived risk and protection factors that may reinforce the ability of children living in refugee camps on the Gaza Strip to adjust to a traumatic and risky life context characterized by loss and dispossession. The sample comprised 200 Palestinian children recruited at primary schools in four refugee camps in the Gaza Strip following the Israeli military operation "Pillar of Defence" in 2012. Thematic content analysis was applied to written materials and narratives produced by the children. Environment, friends, emotions, family, play, self, sociality, health, school, and spirituality were the dimensions that emerged from the narrative texts. Palestinian children's psychological adaptability and ability to reposition themselves along the continuum between ease and disease is underpinned by constant political agency and activism - a dimension that guides sense-making activities in a traumatizing environment marked by continuous uncertainty, loss and bereavement. We therefore recommend a politically-informed focus, both when assessing children and when designing intervention for them in contexts of chronic political violence and war. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Ongoing Recovery Basic Information Tool (ORBIT)

    Science.gov (United States)

    Oberg, Donald

    1993-01-01

    The Federal Drug Free Work Place Program (DFWP) has now matured to the point of being able to return employees to sensitive testing designated positions (TDP) after completion of treatment of their addiction. The known tendency of addicted individuals to suffer multiple relapses prior to their final recovery has resulted in several positive urine tests (relapses) occurring among those Federal employees who have already completed treatment and who have been returned to TDP's. The very real potential for further relapses occurring after additional employees return to TDP's will be a critical factor in the ultimate success of the DFWP and in the public's impression of the program's effectiveness. In response to this concern, NASA has begun development of its Ongoing Recovery Basic Information Tool (ORBIT) instrument. The aim of the NASA ORBIT is to provide Employee Assistance Program (EAP) professionals with an advanced clinical tool which will be helpful in supporting recovery from substance abuse and which will allow more accurate determinations of when clients may be successfully returned to sensitive positions.

  7. Cortical fMRI activation to opponents' body kinematics in sport-related anticipation: expert-novice differences with normal and point-light video.

    Science.gov (United States)

    Wright, M J; Bishop, D T; Jackson, R C; Abernethy, B

    2011-08-18

    Badminton players of varying skill levels viewed normal and point-light video clips of opponents striking the shuttle towards the viewer; their task was to predict in which quadrant of the court the shuttle would land. In a whole-brain fMRI analysis we identified bilateral cortical networks sensitive to the anticipation task relative to control stimuli. This network is more extensive and localised than previously reported. Voxel clusters responding more strongly in experts than novices were associated with all task-sensitive areas, whereas voxels responding more strongly in novices were found outside these areas. Task-sensitive areas for normal and point-light video were very similar, whereas early visual areas responded differentially, indicating the primacy of kinematic information for sport-related anticipation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Investigating the Usability and Acute Effects of a Bedside Video Console to Prefrontal Cortical Activity Alterations: A Preclinical Study in Healthy Elderly.

    Science.gov (United States)

    Knols, Ruud H; Swanenburg, Jaap; De Bon, Dino; Gennaro, Federico; Wolf, Martin; Krüger, Bernard; Bettex, Dominique; de Bruin, Eling D

    2017-01-01

    Elderly people at risk of developing cognitive decline; e.g., following surgery, may benefit from structured, challenging, and repetitive cognitive video training. This study assessed usability and acute effects of a newly developed bedside console (COPHYCON). Fifteen healthy elderly individuals performed a one-time 80-min intervention, including cognitive video games aimed at improving awareness and selective attention. Perceived usefulness and perceived ease of use (Technology Acceptance Model) were assessed together with measures of the achieved game level, reaction times, (in-) correct responses during ALERT and SELECT game play. Further, prefrontal cortical involvement of the regional cerebral hemoglobin saturation (rS02%) assessed with functional near infrared spectroscopy (fNIRS) ( n = 5) and EEG power ( n = 10) was analyzed. All participants completed the study without any adverse events. Perceived usefulness and perceived ease of use (TAM scores range 1-7) of the system varied between 3.9 and 6.3. The game levels reached for awareness varied between 9 and 11 (initial score 8-10), for reaction speed between 439 and 469 ms, and for correct responses between 74.1 and 78.8%. The highest level for the selective attention games was 2 (initial score 1), where reaction speed varied between 439 and 469 ms, correct responses between 96.2 and 98.5%, respectively. The decrease of rS02% in the right prefrontal cortex during gameplay was significantly ( p games ( p games. EEG recordings of theta power significantly decreased in the averaged ~0.25-0.75 time interval for the left prefrontal cortex sensor across the cognitive game levels between the ALERT 1 and SELECT 1, as well as between SELECT 1 and 2 games. Participants rated the usability of the COPHYCON training positively. Further results indicate that video gaming may be an effective measure to affect prefrontal cortical functioning in elderly. The results warrant a clinical explorative study investigating the

  9. Altered Regional Brain Cortical Thickness in Pediatric Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Paul M. Macey

    2018-01-01

    Full Text Available RationaleObstructive sleep apnea (OSA affects 2–5% of all children and is associated with cognitive and behavioral deficits, resulting in poor school performance. These psychological deficits may arise from brain injury, as seen in preliminary findings of lower gray matter volume among pediatric OSA patients. However, the psychological deficits in OSA are closely related to functions in the cortex, and such brain areas have not been specifically assessed. The objective was to determine whether cortical thickness, a marker of possible brain injury, is altered in children with OSA.MethodsWe examined regional brain cortical thicknesses using high-resolution T1-weighted magnetic resonance images in 16 pediatric OSA patients (8 males; mean age ± SD = 8.4 ± 1.2 years; mean apnea/hypopnea index ± SD = 11 ± 6 events/h and 138 controls (8.3 ± 1.1 years; 62 male; 138 subjects from the NIH Pediatric MRI database to identify cortical thickness differences in pediatric OSA subjects.ResultsCortical thinning occurred in multiple regions including the superior frontal, ventral medial prefrontal, and superior parietal cortices. The left side showed greater thinning in the superior frontal cortex. Cortical thickening was observed in bilateral precentral gyrus, mid-to-posterior insular cortices, and left central gyrus, as well as right anterior insula cortex.ConclusionChanges in cortical thickness are present in children with OSA and likely indicate disruption to neural developmental processes, including maturational patterns of cortical volume increases and synaptic pruning. Regions with thicker cortices may reflect inflammation or astrocyte activation. Both the thinning and thickening associated with OSA in children may contribute to the cognitive and behavioral dysfunction frequently found in the condition.

  10. Progressive posterior cortical dysfunction

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  11. Progressive posterior cortical dysfunction

    Science.gov (United States)

    Porto, Fábio Henrique de Gobbi; Machado, Gislaine Cristina Lopes; Morillo, Lilian Schafirovits; Brucki, Sonia Maria Dozzi

    2010-01-01

    Progressive posterior cortical dysfunction (PPCD) is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal) and ventral (occipito-temporal) pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction), complete Balint’s syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right. Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD. PMID:29213665

  12. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  13. Mauna Kea volcano's ongoing 18-year swarm

    Science.gov (United States)

    Wech, A.; Thelen, W. A.

    2017-12-01

    Mauna Kea is a large postshield-stage volcano that forms the highest peak on Hawaii Island. The 4,205-meter high volcano erupted most recently between 6,000 and 4,500 years ago and exhibits relatively low rates of seismicity, which are mostly tectonic in origin resulting from lithospheric flexure under the weight of the volcano. Here we identify deep repeating earthquakes occurring beneath the summit of Mauna Kea. These earthquakes, which are not part of the Hawaiian Volcano Observatory's regional network catalog, were initially detected through a systematic search for coherent seismicity using envelope cross-correlation, and subsequent analysis revealed the presence of a long-term, ongoing swarm. The events have energy concentrated at 2-7 Hz, and can be seen in filtered waveforms dating back to the earliest continuous data from a single station archived at IRIS from November 1999. We use a single-station (3 component) match-filter analysis to create a catalog of the repeating earthquakes for the past 18 years. Using two templates created through phase-weighted stacking of thousands of sta/lta-triggers, we find hundreds of thousands of M1.3-1.6 earthquakes repeating every 7-12 minutes throughout this entire time period, with many smaller events occurring in between. The earthquakes occur at 28-31 km depth directly beneath the summit within a conspicuous gap in seismicity surrounding the flanks of the volcano. Magnitudes and periodicity are remarkably stable long-term, but do exhibit slight variability and occasionally display higher variability on shorter time scales. Network geometry precludes obtaining a reliable focal mechanism, but we interpret the frequency content and hypocenters to infer a volcanic source distinct from the regional tectonic seismicity responding to the load of the island. In this model, the earthquakes may result from the slow, persistent degassing of a relic magma chamber at depth.

  14. Ongoing dengue epidemic - Angola, June 2013.

    Science.gov (United States)

    2013-06-21

    On April 1, 2013, the Public Health Directorate of Angola announced that six cases of dengue had been reported to the Ministry of Health of Angola (MHA). As of May 31, a total of 517 suspected dengue cases had been reported and tested for dengue with a rapid diagnostic test (RDT). A total of 313 (60.5%) specimens tested positive for dengue, including one from a patient who died. All suspected cases were reported from Luanda Province, except for two from Malanje Province. Confirmatory diagnostic testing of 49 specimens (43 RDT-positive and six RDT-negative) at the CDC Dengue Branch confirmed dengue virus (DENV) infection in 100% of the RDT-positive specimens and 50% of the RDT-negative specimens. Only DENV-1 was detected by molecular diagnostic testing. Phylogenetic analysis indicated this virus has been circulating in the region since at least 1968, strongly suggesting that dengue is endemic in Angola. Health-care professionals throughout Angola should be aware of the ongoing epidemic, the recommended practices for clinical management of dengue patients, and the need to report cases to MHA. Persons in Angola should seek medical care for acute febrile illness to reduce the risk for developing complications. Laboratory-confirmed dengue also has been reported from seven countries on four continents among persons who had recently traveled to Luanda, including 79 persons from Portugal. Angola is the third of four African countries to report a dengue outbreak in 2013. Persons returning from Africa with acute febrile illness should seek medical care, including testing for DENV infection, and suspected cases should be reported to public health authorities.

  15. Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil - ongoing activities in Working Project 2.5 of COST Action TU1208

    Science.gov (United States)

    Tosti, Fabio; Slob, Evert

    2015-04-01

    This work will endeavour to review the current status of research activities carried out in Working Project 2.5 'Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil' within the framework of Working Group 2 'GPR surveying of pavements, bridges, tunnels and buildings; underground utility and void sensing' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). Overall, the Project includes 55 Participants from over 21 countries representing 33 Institutions. By considering the type of Institution, a percentage of 64% (35 units) comes from the academic world, while Research Centres and Companies include, respectively, the 27% (15 units) and 9% (5 units) of Institutions. Geographically speaking, Europe is the continent most represented with 18 out of 21 countries, followed by Africa (2 countries) and Asia (1 country). In more details and according to the Europe sub-regions classification provided by the United Nations, Southern Europe includes 39% of countries, Western Europe 27%, while Northern and Eastern Europe are equally present with 17% of countries each. Relying on the main purpose of Working Project 2.5, namely, the ground-penetrating radar-based evaluation of volumetric water content in structures, substructures , foundations, and soils, four main issues have been overall addressed over the first two years of activities. The first one, has been related to provide a comprehensive state of the art on the topic, due to the wide-ranging applications covered in the main disciplines of civil engineering, differently demanding. In this regard, two main publications reviewing the state of the art have been produced [1,2]. Secondly, discussions among Working Group Chairs and other Working Project Leaders have been undertaken and encouraged to avoid the risk of overlapping amongst similar topics from other Working

  16. Functional connectivity and neuronal variability of resting state activity in bipolar disorder--reduction and decoupling in anterior cortical midline structures.

    Science.gov (United States)

    Magioncalda, Paola; Martino, Matteo; Conio, Benedetta; Escelsior, Andrea; Piaggio, Niccolò; Presta, Andrea; Marozzi, Valentina; Rocchi, Giulio; Anastasio, Loris; Vassallo, Linda; Ferri, Francesca; Huang, Zirui; Roccatagliata, Luca; Pardini, Matteo; Northoff, Georg; Amore, Mario

    2015-02-01

    The cortical midline structures seem to be involved in the modulation of different resting state networks, such as the default mode network (DMN) and salience network (SN). Alterations in these systems, in particular in the perigenual anterior cingulate cortex (PACC), seem to play a central role in bipolar disorder (BD). However, the exact role of the PACC, and its functional connections to other midline regions (within and outside DMN) still remains unclear in BD. We investigated functional connectivity (FC), standard deviation (SD, as a measure of neuronal variability) and their correlation in bipolar patients (n = 40) versus healthy controls (n = 40), in the PACC and in its connections in different frequency bands (standard: 0.01-0.10 Hz; Slow-5: 0.01-0.027 Hz; Slow-4: 0.027-0.073 Hz). Finally, we studied the correlations between FC alterations and clinical-neuropsychological parameters and we explored whether subgroups of patients in different phases of the illness present different patterns of FC abnormalities. We found in BD decreased FC (especially in Slow-5) from the PACC to other regions located predominantly in the posterior DMN (such as the posterior cingulate cortex (PCC) and inferior temporal gyrus) and in the SN (such as the supragenual anterior cingulate cortex and ventrolateral prefrontal cortex). Second, we found in BD a decoupling between PACC-based FC and variability in the various target regions (without alteration in variability itself). Finally, in our subgroups explorative analysis, we found a decrease in FC between the PACC and supragenual ACC (in depressive phase) and between the PACC and PCC (in manic phase). These findings suggest that in BD the communication, that is, information transfer, between the different cortical midline regions within the cingulate gyrus does not seem to work properly. This may result in dysbalance between different resting state networks like the DMN and SN. A deficit in the anterior DMN-SN connectivity

  17. Investigating the Usability and Acute Effects of a Bedside Video Console to Prefrontal Cortical Activity Alterations: A Preclinical Study in Healthy Elderly

    Directory of Open Access Journals (Sweden)

    Ruud H. Knols

    2017-11-01

    Full Text Available Elderly people at risk of developing cognitive decline; e.g., following surgery, may benefit from structured, challenging, and repetitive cognitive video training. This study assessed usability and acute effects of a newly developed bedside console (COPHYCON. Fifteen healthy elderly individuals performed a one-time 80-min intervention, including cognitive video games aimed at improving awareness and selective attention. Perceived usefulness and perceived ease of use (Technology Acceptance Model were assessed together with measures of the achieved game level, reaction times, (in- correct responses during ALERT and SELECT game play. Further, prefrontal cortical involvement of the regional cerebral hemoglobin saturation (rS02% assessed with functional near infrared spectroscopy (fNIRS (n = 5 and EEG power (n = 10 was analyzed. All participants completed the study without any adverse events. Perceived usefulness and perceived ease of use (TAM scores range 1–7 of the system varied between 3.9 and 6.3. The game levels reached for awareness varied between 9 and 11 (initial score 8–10, for reaction speed between 439 and 469 ms, and for correct responses between 74.1 and 78.8%. The highest level for the selective attention games was 2 (initial score 1, where reaction speed varied between 439 and 469 ms, correct responses between 96.2 and 98.5%, respectively. The decrease of rS02% in the right prefrontal cortex during gameplay was significantly (p < 0.001 lower, compared to the left prefrontal cortex. Four participants yielded significant lower rS02% measures after exergaming with the ALERT games (p < 0.000, but not with the SELECT games. EEG recordings of theta power significantly decreased in the averaged ~0.25–0.75 time interval for the left prefrontal cortex sensor across the cognitive game levels between the ALERT 1 and SELECT 1, as well as between SELECT 1 and 2 games. Participants rated the usability of the COPHYCON training positively

  18. Dynamics of Ionic Shifts in Cortical Spreading Depression.

    Science.gov (United States)

    Enger, Rune; Tang, Wannan; Vindedal, Gry Fluge; Jensen, Vidar; Johannes Helm, P; Sprengel, Rolf; Looger, Loren L; Nagelhus, Erlend A

    2015-11-01

    Cortical spreading depression is a slowly propagating wave of near-complete depolarization of brain cells followed by temporary suppression of neuronal activity. Accumulating evidence indicates that cortical spreading depression underlies the migraine aura and that similar waves promote tissue damage in stroke, trauma, and hemorrhage. Cortical spreading depression is characterized by neuronal swelling, profound elevation of extracellular potassium and glutamate, multiphasic blood flow changes, and drop in tissue oxygen tension. The slow speed of the cortical spreading depression wave implies that it is mediated by diffusion of a chemical substance, yet the identity of this substance and the pathway it follows are unknown. Intercellular spread between gap junction-coupled neurons or glial cells and interstitial diffusion of K(+) or glutamate have been proposed. Here we use extracellular direct current potential recordings, K(+)-sensitive microelectrodes, and 2-photon imaging with ultrasensitive Ca(2+) and glutamate fluorescent probes to elucidate the spatiotemporal dynamics of ionic shifts associated with the propagation of cortical spreading depression in the visual cortex of adult living mice. Our data argue against intercellular spread of Ca(2+) carrying the cortical spreading depression wavefront and are in favor of interstitial K(+) diffusion, rather than glutamate diffusion, as the leading event in cortical spreading depression. © The Author 2015. Published by Oxford University Press.

  19. Adult-onset Rasmussen encephalitis associated with focal cortical dysplasia.

    Science.gov (United States)

    Hohenbichler, Katharina; Lelotte, Julie; Lhommel, Renaud; Tahry, Riëm El; Vrielynck, Pascal; Santos, Susana Ferrao

    2017-12-01

    Rasmussen encephalitis is a rare, devastating condition, typically presenting in childhood. Cases of adult-onset Rasmussen have also been described, but the clinical picture is less defined, rendering final diagnosis difficult. We present a case of adult-onset Rasmussen encephalitis with dual pathology, associated with focal cortical dysplasia and encephalitis. We interpreted the Rasmussen encephalitis to be caused by severe and continuous epileptic activity due to focal cortical dysplasia. The best therapeutic approach for such cases remains unclear.

  20. Can monaural temporal masking explain the ongoing precedence effect?

    Science.gov (United States)

    Freyman, Richard L; Morse-Fortier, Charlotte; Griffin, Amanda M; Zurek, Patrick M

    2018-02-01

    The precedence effect for transient sounds has been proposed to be based primarily on monaural processes, manifested by asymmetric temporal masking. This study explored the potential for monaural explanations with longer ("ongoing") sounds exhibiting the precedence effect. Transient stimuli were single lead-lag noise burst pairs; ongoing stimuli were trains of 63 burst pairs. Unlike with transients, monaural masking data for ongoing sounds showed no advantage for the lead, and are inconsistent with asymmetric audibility as an explanation for ongoing precedence. This result, along with supplementary measurements of interaural time discrimination, suggests different explanations for transient and ongoing precedence.

  1. EIDA Next Generation: ongoing and future developments

    Science.gov (United States)

    Strollo, Angelo; Quinteros, Javier; Sleeman, Reinoud; Trani, Luca; Clinton, John; Stammler, Klaus; Danecek, Peter; Pedersen, Helle; Ionescu, Constantin

    2015-04-01

    The European Integrated Data Archive (EIDA; http://www.orfeus-eu.org/eida/eida.html) is the distributed Data Centre system within ORFEUS, providing transparent access and services to high quality, seismic data across (currently) 9 large data archives in Europe. EIDA is growing, in terms of the number of participating data centres, the size of the archives, the variability of the data in the archives, the number of users, and the volume of downloads. The on-going success of EIDA is thus providing challenges that are the driving force behind the design of the next generation (NG) of EIDA, which is expected to be implemented within EPOS IP. EIDA ORFEUS must cope with further expansion of the system and more complex user requirements by developing new techniques and extended services. The EIDA NG is being designed to work on standard FDSN web services and two additional new web services: Routing Service and QC (quality controlled) service. This presentation highlights the challenges EIDA needs to address during the EPOS IP and focuses on these 2 new services. The Routing Service can be considered as the core of EIDA NG. It was designed to assist users and clients to locate data within a federated, decentralized data centre (e.g. EIDA). A detailed, FDSN-compliant specification of the service has been developed. Our implementation of this service will run at every EIDA node, but is also capable of running on a user's computer, allowing anyone to define virtual or integrate existing data centres. This (meta)service needs to be queried in order to locate the data. Some smart clients (in a beta status) have been also provided to offer the user an integrated view of the whole EIDA, hiding the complexity of its internal structure. The service is open and able to be queried by anyone without the need of credentials or authentication. The QC Service is developed to cope with user requirements to query for relevant data only. The web service provides detailed information on the

  2. Assessment of former uranium sites and their ongoing remediation activities

    International Nuclear Information System (INIS)

    Khakimov, N.; Adkhamov, A.; Nazarov, Kh.M.; Mahmadov, T.; Mirsaidov, I.U.

    2012-01-01

    Carried out analysis on tailing's buildings operation shows that period for engineer barrier service, taking into account any catastrophic natural impacts, is too little in comparison with life-time of long-live radionuclides. Priorities should be defined by danger degree and isolation costs (protection optimization), therefore uncommon, non-traditional methods, developed taking into account natural factors for long-live waste (radionuclides) isolation are necessary. That's why, it is necessary to carry out specialized research and development, design and exploratory and other works on monitoring of social-ecological condition of these sites, as well as on demographic public diseases, living in these regions.

  3. Cortical entrainment to music and its modulation by expertise.

    Science.gov (United States)

    Doelling, Keith B; Poeppel, David

    2015-11-10

    Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15-30 Hz)-often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition.

  4. Plasticity of cortical excitatory-inhibitory balance.

    Science.gov (United States)

    Froemke, Robert C

    2015-07-08

    Synapses are highly plastic and are modified by changes in patterns of neural activity or sensory experience. Plasticity of cortical excitatory synapses is thought to be important for learning and memory, leading to alterations in sensory representations and cognitive maps. However, these changes must be coordinated across other synapses within local circuits to preserve neural coding schemes and the organization of excitatory and inhibitory inputs, i.e., excitatory-inhibitory balance. Recent studies indicate that inhibitory synapses are also plastic and are controlled directly by a large number of neuromodulators, particularly during episodes of learning. Many modulators transiently alter excitatory-inhibitory balance by decreasing inhibition, and thus disinhibition has emerged as a major mechanism by which neuromodulation might enable long-term synaptic modifications naturally. This review examines the relationships between neuromodulation and synaptic plasticity, focusing on the induction of long-term changes that collectively enhance cortical excitatory-inhibitory balance for improving perception and behavior.

  5. Identification of a brainstem circuit regulating visual cortical state in parallel with locomotion.

    Science.gov (United States)

    Lee, A Moses; Hoy, Jennifer L; Bonci, Antonello; Wilbrecht, Linda; Stryker, Michael P; Niell, Cristopher M

    2014-07-16

    Sensory processing is dependent upon behavioral state. In mice, locomotion is accompanied by changes in cortical state and enhanced visual responses. Although recent studies have begun to elucidate intrinsic cortical mechanisms underlying this effect, the neural circuits that initially couple locomotion to cortical processing are unknown. The mesencephalic locomotor region (MLR) has been shown to be capable of initiating running and is associated with the ascending reticular activating system. Here, we find that optogenetic stimulation of the MLR in awake, head-fixed mice can induce both locomotion and increases in the gain of cortical responses. MLR stimulation below the threshold for overt movement similarly changed cortical processing, revealing that MLR's effects on cortex are dissociable from locomotion. Likewise, stimulation of MLR projections to the basal forebrain also enhanced cortical responses, suggesting a pathway linking the MLR to cortex. These studies demonstrate that the MLR regulates cortical state in parallel with locomotion. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. The maturation of cortical sleep rhythms and networks over early development

    OpenAIRE

    Chu, Catherine Jean; Leahy, J.; Pathmanathan, Jay Sriram; Kramer, M.A.; Cash, Sydney S.

    2014-01-01

    Objective: Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development. Methods: We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state. ...

  7. Mitogen-activated protein kinase signaling pathways promote low-density lipoprotein receptor-related protein 1-mediated internalization of beta-amyloid protein in primary cortical neurons.

    Science.gov (United States)

    Yang, Wei-Na; Ma, Kai-Ge; Qian, Yi-Hua; Zhang, Jian-Shui; Feng, Gai-Feng; Shi, Li-Li; Zhang, Zhi-Chao; Liu, Zhao-Hui

    2015-07-01

    Mounting evidence suggests that the pathological hallmarks of Alzheimer's disease (AD) are caused by the intraneuronal accumulation of beta-amyloid protein (Aβ). Reuptake of extracellular Aβ is believed to contribute significantly to the intraneuronal Aβ pool in the early stages of AD. Published reports have claimed that the low-density lipoprotein receptor-related protein 1 (LRP1) mediates Aβ1-42 uptake and lysosomal trafficking in GT1-7 neuronal cells and mouse embryonic fibroblast non-neuronal cells. However, there is no direct evidence supporting the role of LRP1 in Aβ internalization in primary neurons. Our recent study indicated that p38 MAPK and ERK1/2 signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor (α7nAChR)-mediated Aβ1-42 uptake in SH-SY5Y cells. This study was designed to explore the regulation of MAPK signaling pathways on LRP1-mediated Aβ internalization in neurons. We found that extracellular Aβ1-42 oligomers could be internalized into endosomes/lysosomes and mitochondria in cortical neurons. Aβ1-42 and LRP1 were also found co-localized in neurons during Aβ1-42 internalization, and they could form Aβ1-42-LRP1 complex. Knockdown of LRP1 expression significantly decreased neuronal Aβ1-42 internalization. Finally, we identified that p38 MAPK and ERK1/2 signaling pathways regulated the internalization of Aβ1-42 via LRP1. Therefore, these results demonstrated that LRP1, p38 MAPK and ERK1/2 mediated the internalization of Aβ1-42 in neurons and provided evidence that blockade of LRP1 or inhibitions of MAPK signaling pathways might be a potential approach to lowering brain Aβ levels and served a potential therapeutic target for AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Phenolic acid intake, delivered via moderate champagne wine consumption, improves spatial working memory via the modulation of hippocampal and cortical protein expression/activation.

    Science.gov (United States)

    Corona, Giulia; Vauzour, David; Hercelin, Justine; Williams, Claire M; Spencer, Jeremy P E

    2013-11-10

    While much data exist for the effects of flavonoid-rich foods on spatial memory in rodents, there are no such data for foods/beverages predominantly containing hydroxycinnamates and phenolic acids. To address this, we investigated the effects of moderate Champagne wine intake, which is rich in these components, on spatial memory and related mechanisms relative to the alcohol- and energy-matched controls. In contrast to the isocaloric and alcohol-matched controls, supplementation with Champagne wine (1.78 ml/kg BW, alcohol 12.5% vol.) for 6 weeks led to an improvement in spatial working memory in aged rodents. Targeted protein arrays indicated that these behavioral effects were paralleled by the differential expression of a number of hippocampal and cortical proteins (relative to the isocaloric control group), including those involved in signal transduction, neuroplasticity, apoptosis, and cell cycle regulation. Western immunoblotting confirmed the differential modulation of brain-derived neurotrophic factor, cAMP response-element-binding protein (CREB), p38, dystrophin, 2',3'-cyclic-nucleotide 3'-phosphodiesterase, mammalian target of rapamycin (mTOR), and Bcl-xL in response to Champagne supplementation compared to the control drink, and the modulation of mTOR, Bcl-xL, and CREB in response to alcohol supplementation. Our data suggest that smaller phenolics such as gallic acid, protocatechuic acid, tyrosol, caftaric acid, and caffeic acid, in addition to flavonoids, are capable of exerting improvements in spatial memory via the modulation in hippocampal signaling and protein expression. Changes in spatial working memory induced by the Champagne supplementation are linked to the effects of absorbed phenolics on cytoskeletal proteins, neurotrophin expression, and the effects of alcohol on the regulation of apoptotic events in the hippocampus and cortex.

  9. Classification of Cortical Brain Malformations

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-03-01

    Full Text Available Clinical, radiological, and genetic classifications of 113 cases of malformations of cortical development (MCD were evaluated at the Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.

  10. Focal cortical dysplasia – review

    International Nuclear Information System (INIS)

    Kabat, Joanna; Król, Przemysław

    2012-01-01

    Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults. Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed – from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized. Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe. Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes. New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life. Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias. The most common findings on MRI imaging include: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy. However, in type I cortical dysplasia, MR imaging is often normal, and also in both

  11. Ongoing Analysis of Jupiter's Equatorial Hotspots and Plumes from Cassini

    Science.gov (United States)

    Choi, D. S.; Showmwn, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated results from our ongoing analysis of Cassini observations of Jupiter's equatorial meteorology. For two months preceding the spacecraft's closest approach of the planet, the ISS instrument onboard Cassini regularly imaged the atmosphere of Jupiter. We created time-lapse movies from this period that show the complex activity and interactions of the equatorial atmosphere. During this period, hot spots exhibited significant variations in size and shape over timescales of days and weeks. Some of these changes appear to be a result of interactions with passing vortex systems in adjacent latitudes. Strong anticyclonic gyres to the southeast of the dark areas converge with flow from the west and appear to circulate into a hot spot at its southwestern corner.

  12. Group crisis intervention for children during ongoing war conflict.

    Science.gov (United States)

    Thabet, Abdel Aziz; Vostanis, Panos; Karim, Khalid

    2005-08-01

    The aim of this study was to evaluate the short-term impact of a group crisis intervention for children aged 9-15 years from five refugee camps in the Gaza Strip during ongoing war conflict. Children were selected if they reported moderate to severe posttraumatic stress reactions, and were allocated to group intervention (N=47) encouraging expression of experiences and emotions through storytelling, drawing, free play and role-play; education about symptoms (N=22); or no intervention (N=42). Children completed the CPTSD-RI and the CDI pre- and post-intervention. No significant impact of the group intervention was established on children's posttraumatic or depressive symptoms. Possible explanations of the findings are discussed, including the continuing exposure to trauma and the non-active nature of the intervention.

  13. Spatial integration and cortical dynamics.

    Science.gov (United States)

    Gilbert, C D; Das, A; Ito, M; Kapadia, M; Westheimer, G

    1996-01-23

    Cells in adult primary visual cortex are capable of integrating information over much larger portions of the visual field than was originally thought. Moreover, their receptive field properties can be altered by the context within which local features are presented and by changes in visual experience. The substrate for both spatial integration and cortical plasticity is likely to be found in a plexus of long-range horizontal connections, formed by cortical pyramidal cells, which link cells within each cortical area over distances of 6-8 mm. The relationship between horizontal connections and cortical functional architecture suggests a role in visual segmentation and spatial integration. The distribution of lateral interactions within striate cortex was visualized with optical recording, and their functional consequences were explored by using comparable stimuli in human psychophysical experiments and in recordings from alert monkeys. They may represent the substrate for perceptual phenomena such as illusory contours, surface fill-in, and contour saliency. The dynamic nature of receptive field properties and cortical architecture has been seen over time scales ranging from seconds to months. One can induce a remapping of the topography of visual cortex by making focal binocular retinal lesions. Shorter-term plasticity of cortical receptive fields was observed following brief periods of visual stimulation. The mechanisms involved entailed, for the short-term changes, altering the effectiveness of existing cortical connections, and for the long-term changes, sprouting of axon collaterals and synaptogenesis. The mutability of cortical function implies a continual process of calibration and normalization of the perception of visual attributes that is dependent on sensory experience throughout adulthood and might further represent the mechanism of perceptual learning.

  14. Spatial integration and cortical dynamics.

    OpenAIRE

    Gilbert, C D; Das, A; Ito, M; Kapadia, M; Westheimer, G

    1996-01-01

    Cells in adult primary visual cortex are capable of integrating information over much larger portions of the visual field than was originally thought. Moreover, their receptive field properties can be altered by the context within which local features are presented and by changes in visual experience. The substrate for both spatial integration and cortical plasticity is likely to be found in a plexus of long-range horizontal connections, formed by cortical pyramidal cells, which link cells wi...

  15. Cortical desmoid of the humerus: radiographic and MRI correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Matthew; Counsel, Peter [Princess Margaret Hospital for Children, Department of Diagnostic Imaging, Perth (Australia); Perth Radiological Clinic, Perth (Australia); Wood, David [Princess Margaret Hospital for Children, Department of Orthopedic Surgery, Perth (Australia); Breidahl, William [Perth Radiological Clinic, Perth (Australia)

    2017-07-15

    Cortical desmoids are self-limiting fibro-osseous lesions commonly occurring at the medial supracondylar femur in active adolescents, at either the origin of the medial head of the gastrocnemius or at the insertion of the adductor magnus aponeurosis. Less commonly, in a similar demographic, cortical desmoids may occur in the proximal humerus medially at the insertion of the pectoralis major muscle or laterally at the insertion of the deltoid. The radiographic appearance of the proximal humerus cortical desmoid has been described previously, but not the MRI appearance. We present the radiographic and MRI appearances of a proximal humerus cortical desmoid in a young adolescent who presented for investigation of right shoulder pain. (orig.)

  16. Cortical desmoid of the humerus: radiographic and MRI correlation

    International Nuclear Information System (INIS)

    Kay, Matthew; Counsel, Peter; Wood, David; Breidahl, William

    2017-01-01

    Cortical desmoids are self-limiting fibro-osseous lesions commonly occurring at the medial supracondylar femur in active adolescents, at either the origin of the medial head of the gastrocnemius or at the insertion of the adductor magnus aponeurosis. Less commonly, in a similar demographic, cortical desmoids may occur in the proximal humerus medially at the insertion of the pectoralis major muscle or laterally at the insertion of the deltoid. The radiographic appearance of the proximal humerus cortical desmoid has been described previously, but not the MRI appearance. We present the radiographic and MRI appearances of a proximal humerus cortical desmoid in a young adolescent who presented for investigation of right shoulder pain. (orig.)

  17. Cerebellar Shaping of Motor Cortical Firing Is Correlated with Timing of Motor Actions

    Directory of Open Access Journals (Sweden)

    Abdulraheem Nashef

    2018-05-01

    Full Text Available Summary: In higher mammals, motor timing is considered to be dictated by cerebellar control of motor cortical activity, relayed through the cerebellar-thalamo-cortical (CTC system. Nonetheless, the way cerebellar information is integrated with motor cortical commands and affects their temporal properties remains unclear. To address this issue, we activated the CTC system in primates and found that it efficiently recruits motor cortical cells; however, the cortical response was dominated by prolonged inhibition that imposed a directional activation across the motor cortex. During task performance, cortical cells that integrated CTC information fired synchronous bursts at movement onset. These cells expressed a stronger correlation with reaction time than non-CTC cells. Thus, the excitation-inhibition interplay triggered by the CTC system facilitates transient recruitment of a cortical subnetwork at movement onset. The CTC system may shape neural firing to produce the required profile to initiate movements and thus plays a pivotal role in timing motor actions. : Nashef et al. identified a motor cortical subnetwork recruited by cerebellar volley that was transiently synchronized at movement onset. Cerebellar control of cortical firing was dominated by inhibition that shaped task-related firing of neurons and may dictate motor timing. Keywords: motor control, primates, cerebellar-thalamo-cortical, synchrony, noise correlation, reaction time

  18. Biomechanics of far cortical locking.

    Science.gov (United States)

    Bottlang, Michael; Feist, Florian

    2011-02-01

    The development of far cortical locking (FCL) was motivated by a conundrum: locked plating constructs provide inherently rigid stabilization, yet they should facilitate biologic fixation and secondary bone healing that relies on flexible fixation to stimulate callus formation. Recent studies have confirmed that the high stiffness of standard locked plating constructs can suppress interfragmentary motion to a level that is insufficient to reliably promote secondary fracture healing by callus formation. Furthermore, rigid locking screws cause an uneven stress distribution that may lead to stress fracture at the end screw and stress shielding under the plate. This review summarizes four key features of FCL constructs that have been shown to enhance fixation and healing of fractures: flexible fixation, load distribution, progressive stiffening, and parallel interfragmentary motion. Specifically, flexible fixation provided by FCL reduces the stiffness of a locked plating construct by 80% to 88% to actively promote callus proliferation similar to an external fixator. Load is evenly distributed between FCL screws to mitigate stress risers at the end screw. Progressive stiffening occurs by near cortex support of FCL screws and provides additional support under elevated loading. Finally, parallel interfragmentary motion by the S-shaped flexion of FCL screws promotes symmetric callus formation. In combination, these features of FCL constructs have been shown to induce more callus and to yield significantly stronger and more consistent healing compared with standard locked plating constructs. As such, FCL constructs function as true internal fixators by replicating the biomechanical behavior and biologic healing response of external fixators.

  19. The cortical representation of sensory inputs arising from bone.

    Science.gov (United States)

    Ivanusic, Jason J; Sahai, Vineet; Mahns, David A

    2009-05-07

    In the present study, we show that sensory information from bone reaches the discriminative areas of the somatosensory cortices by electrically stimulating the nerve to the cat humerus and recording evoked potentials on the surface of the primary (SI) and secondary (SII) somatosensory cortex. The SI focus was located over the rostral part of the postcruciate cortex, caudal to the lateral aspect of the cruciate sulcus. The SII focus was identified on the anterior ectosylvian gyrus, lateral to the suprasylvian sulcus. These foci were located adjacent to, or within areas that responded to stimulation of the median, ulnar and/or musculocutaneous nerves. The latency (6-11 ms) to onset of cortical responses in SI and SII were indistinguishable (unpaired t-test; P>0.05), and were consistent with activation of A delta fibers in the peripheral nerve. The amplitudes of the cortical responses were graded as a function of stimulus intensity, and may reflect a mechanism for intensity coding. We did not observe long latency cortical responses (50-300 ms) that would be consistent with C fiber activation in the peripheral nerve, and provide evidence that this may be attributable to inhibition of cortical responsiveness following the initial A delta response. Our finding of discrete, short latency evoked potentials (presumably of A delta origin) in the primary and secondary somatosensory cortices, following stimulation of a nerve innervating bone, may reflect a mechanism for the discriminative component of bone pain.

  20. Somatostatin-expressing inhibitory interneurons in cortical circuits

    Directory of Open Access Journals (Sweden)

    Iryna Yavorska

    2016-09-01

    Full Text Available Cortical inhibitory neurons exhibit remarkable diversity in their morphology, connectivity, and synaptic properties. Here, we review the function of somatostatin-expressing (SOM inhibitory interneurons, focusing largely on sensory cortex. SOM neurons also comprise a number of subpopulations that can be distinguished by their morphology, input and output connectivity, laminar location, firing properties, and expression of molecular markers. Several of these classes of SOM neurons show unique dynamics and characteristics, such as facilitating synapses, specific axonal projections, intralaminar input, and top-down modulation, which suggest possible computational roles. SOM cells can be differentially modulated by behavioral state depending on their class, sensory system, and behavioral paradigm. The functional effects of such modulation have been studied with optogenetic manipulation of SOM cells, which produces effects on learning and memory, task performance, and the integration of cortical activity. Different classes of SOM cells participate in distinct disinhibitory circuits with different inhibitory partners and in different cortical layers. Through these disinhibitory circuits, SOM cells help encode the behavioral relevance of sensory stimuli by regulating the activity of cortical neurons based on subcortical and intracortical modulatory input. Associative learning leads to long-term changes in the strength of connectivity of SOM cells with other neurons, often influencing the strength of inhibitory input they receive. Thus despite their heterogeneity and variability across cortical areas, current evidence shows that SOM neurons perform unique neural computations, forming not only distinct molecular but also functional subclasses of cortical inhibitory interneurons.

  1. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  2. Inadequate description of educational interventions in ongoing randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Pino Cécile

    2012-05-01

    Full Text Available Abstract Background The registration of clinical trials has been promoted to prevent publication bias and increase research transparency. Despite general agreement about the minimum amount of information needed for trial registration, we lack clear guidance on descriptions of non-pharmacologic interventions in trial registries. We aimed to evaluate the quality of registry descriptions of non-pharmacologic interventions assessed in ongoing randomized controlled trials (RCTs of patient education. Methods On 6 May 2009, we searched for all ongoing RCTs registered in the 10 trial registries accessible through the World Health Organization International Clinical Trials Registry Platform. We included trials evaluating an educational intervention (that is, designed to teach or train patients about their own health and dedicated to participants, their family members or home caregivers. We used a standardized data extraction form to collect data related to the description of the experimental intervention, the centers, and the caregivers. Results We selected 268 of 642 potentially eligible studies and appraised a random sample of 150 records. All selected trials were registered in 4 registers, mainly ClinicalTrials.gov (61%. The median [interquartile range] target sample size was 205 [100 to 400] patients. The comparator was mainly usual care (47% or active treatment (47%. A minority of records (17%, 95% CI 11 to 23% reported an overall adequate description of the intervention (that is, description that reported the content, mode of delivery, number, frequency, duration of sessions and overall duration of the intervention. Further, for most reports (59%, important information about the content of the intervention was missing. The description of the mode of delivery of the intervention was reported for 52% of studies, the number of sessions for 74%, the frequency of sessions for 58%, the duration of each session for 45% and the overall duration for 63

  3. The cortical signature of amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Federica Agosta

    Full Text Available The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74. Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03. Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

  4. The cortical signature of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Agosta, Federica; Valsasina, Paola; Riva, Nilo; Copetti, Massimiliano; Messina, Maria Josè; Prelle, Alessandro; Comi, Giancarlo; Filippi, Massimo

    2012-01-01

    The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS) and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic) within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74). Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03). Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

  5. Cortical tremor: a variant of cortical reflex myoclonus.

    Science.gov (United States)

    Ikeda, A; Kakigi, R; Funai, N; Neshige, R; Kuroda, Y; Shibasaki, H

    1990-10-01

    Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture.