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Sample records for chronic multi-electrode neural

  1. Early interfaced neural activity from chronic amputated nerves

    Directory of Open Access Journals (Sweden)

    Kshitija Garde

    2009-05-01

    Full Text Available Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees. Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user. However, reactive gliosis, micro hemorrhages, axonopathy and excessive inflammation, currently limit their long-term use. Here we demonstrate that enticement of peripheral nerve regeneration through a non-obstructive multi-electrode array, after either acute or chronic nerve amputation, offers a viable alternative to obtain early neural recordings and to enhance long-term interfacing of nerve activity. Non restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface. Our findings suggest that regenerative on-dependent multi-electrode arrays of open design allow the early and stable interfacing of neural activity from amputated peripheral nerves and might contribute towards conveying full neural control and sensory feedback to users of robotic prosthetic devices. .

  2. A lightweight feedback-controlled microdrive for chronic neural recordings

    Science.gov (United States)

    Jovalekic, A.; Cavé-Lopez, S.; Canopoli, A.; Ondracek, J. M.; Nager, A.; Vyssotski, A. L.; Hahnloser, R. H. R.

    2017-04-01

    Objective. Chronic neural recordings have provided many insights into the relationship between neural activity and behavior. We set out to develop a miniaturized motorized microdrive that allows precise electrode positioning despite possibly unreliable motors. Approach. We designed a feedback-based motor control mechanism. It contains an integrated position readout from an array of magnets and a Hall sensor. Main results. Our extremely lightweight (feedback-based microdrive control requires little extra size and weight, suggesting that such control can be incorporated into more complex multi-electrode designs.

  3. Ultrasoft microwire neural electrodes improve chronic tissue integration.

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    Du, Zhanhong Jeff; Kolarcik, Christi L; Kozai, Takashi D Y; Luebben, Silvia D; Sapp, Shawn A; Zheng, Xin Sally; Nabity, James A; Cui, X Tracy

    2017-02-06

    Chronically implanted neural multi-electrode arrays (MEA) are an essential technology for recording electrical signals from neurons and/or modulating neural activity through stimulation. However, current MEAs, regardless of the type, elicit an inflammatory response that ultimately leads to device failure. Traditionally, rigid materials like tungsten and silicon have been employed to interface with the relatively soft neural tissue. The large stiffness mismatch is thought to exacerbate the inflammatory response. In order to minimize the disparity between the device and the brain, we fabricated novel ultrasoft electrodes consisting of elastomers and conducting polymers with mechanical properties much more similar to those of brain tissue than previous neural implants. In this study, these ultrasoft microelectrodes were inserted and released using a stainless steel shuttle with polyethyleneglycol (PEG) glue. The implanted microwires showed functionality in acute neural stimulation. When implanted for 1 or 8weeks, the novel soft implants demonstrated significantly reduced inflammatory tissue response at week 8 compared to tungsten wires of similar dimension and surface chemistry. Furthermore, a higher degree of cell body distortion was found next to the tungsten implants compared to the polymer implants. Our results support the use of these novel ultrasoft electrodes for long term neural implants.

  4. A split microdrive for simultaneous multi-electrode recordings from two brain areas in awake small animals.

    NARCIS (Netherlands)

    C.S. Lansink; M. Bakker; W. Buster; J. Lankelma; R. van der Blom; R. Westdorp; R.N.J.M.A. Joosten; B.L. Mc.Naughton; C.M.A. Pennartz

    2007-01-01

    Complex cognitive operations such as memory formation and decision-making are thought to be mediated not by single, isolated brain structures but by multiple, connected brain areas. To facilitate studies on the neural communication between connected brain structures, we developed a multi-electrode m

  5. A multi-electrode biomimetic electrolocation sensor

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    Mayekar, K.; Damalla, D.; Gottwald, M.; Bousack, H.; von der Emde, G.

    2012-04-01

    We present the concept of an active multi-electrode catheter inspired by the electroreceptive system of the weakly electric fish, Gnathonemus petersii. The skin of this fish exhibits numerous electroreceptor organs which are capable of sensing a self induced electrical field. Our sensor is composed of a sending electrode and sixteen receiving electrodes. The electrical field produced by the sending electrode was measured by the receiving electrodes and objects were detected by the perturbation of the electrical field they induce. The intended application of such a sensor is in coronary diagnostics, in particular in distinguishing various types of plaques, which are major causes of heart attack. For calibration of the sensor system, finite element modeling (FEM) was performed. To validate the model, experimental measurements were carried out with two different systems. The physical system was glass tubing with metal and plastic wall insertions as targets. For the control of the experiment and for data acquisition, the software LabView designed for 17 electrodes was used. Different parameters of the electric images were analyzed for the prediction of the electrical properties and size of the inserted targets in the tube. Comparisons of the voltage modulations predicted from the FEM model and the experiments showed a good correspondence. It can be concluded that this novel biomimetic method can be further developed for detailed investigations of atherosclerotic lesions. Finally, we discuss various design strategies to optimize the output of the sensor using different simulated models to enhance target recognition.

  6. Extraction of network topology from multi-electrode recordings: Is there a small-world effect?

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    Felipe eGerhard

    2011-02-01

    Full Text Available The simultaneous recording of the activity of many neurons poses challenges for multivariate data analysis. Here, we propose a general scheme of reconstruction of the functional network from spike train recordings. Effective, causal interactions are estimated by fitting Generalized Linear Models (GLMs on the neural responses, incorporating effects of the neurons' self-history, of input from other neurons in the recorded network and of modulation by an external stimulus. The coupling terms arising from synaptic input can be transformed by thresholding into a binary connectivity matrix which is directed. Each link between two neurons represents a causal influence from one neuron to the other, given the observation of all other neurons from the population. The resulting graph is analyzed with respect to small-world and scale-free properties using quantitative measures for directed networks. Such graph-theoretic analyses have been performed on many complex dynamic networks, including the connectivity structure between different brain areas. Only few studies have attempted to look at the structure of cortical neural networks on the level of individual neurons. Here, using multi-electrode recordings from the visual system of the awake monkey, we find that cortical networks lack scale-free behavior, but show a small, but significant small-world structure. Assuming a simple distance-dependent probabilistic wiring between neurons, we find that this connectivity structure can account for all of the networks' observed small-world-ness. Moreover, for multi-electrode recordings the sampling of neurons is not uniform across the population. We show that the small-world-ness obtained by such a localized sub-sampling overestimates the strength of the true small-world-structure of the network. This bias is likely to be present in all previous experiments based on multi-electrode recordings.

  7. Classification of Chronic Whiplash Associated Disorders With Artificial Neural Networks

    Science.gov (United States)

    2007-11-02

    question is how to analyse a multiple of features in an appropriate way. Different Artificial Neural Networks (ANN) have been developed during the past...sample IR-light, at 60 Hz, reflected by the retro-reflective markers. CLASSIFICATION OF CHRONIC WHIPLASH ASSOCIATED DISORDERS WITH ARTIFICIAL NEURAL NETWORKS F...Associated Disorders With Artificial Neural Networks Contract Number Grant Number Program Element Number Author(s) Project Number Task Number

  8. Evaluation and use of regenerative multi electrode interfaces in peripheral nerves

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    Desai, Vidhi

    Peripheral nerves offer unique accessibility to the innate motor and sensory pathways that can be interfaced with high degree of selectivity for intuitive and bidirectional control of advanced upper extremity prosthetic limbs. Several peripheral nerve interfaces have been proposed and investigated over the last few decades with significant progress made in the area of sensory feedback. However, clinical translation still remains a formidable challenge due to the lack of long term recordings. Prominent causes include signal degradation, eventual interface failures, and lack of specificity in the low amplitude nerve signals. This dissertation evaluates the capabilities of the newly developed Regenerative Multi-electrode Interface (REMI) by the characterization of signal quality progression, the identification of interfaced axon types, and the demonstration of "functional linkage" between acquired signals and target organs. Chapter 2 details the chronic recording of high quality signals from REMI in sciatic nerve which remained stable over a 120 day implantation period indicative of minimal ongoing tissue response with no detrimental effects on the recording ability. The dominant cause of failures was attributable to abiotic factors pertaining to the connector/wire breakage, observed in 76% of REMI implants. Also, the REMI implants had 20% higher success rate and significantly larger Signal to Noise Ratio (SNR) in comparison to the Utah Slanted Electrode Array (USEA). Chapter 3 describes the successful feasibility of interfacing with motor and sensory axons by REMI implantation in the tibial and sural fascicles of the sciatic nerve. A characteristic sampling bias towards recording signals from medium-to-large diameter axons that are primarily involved in mechanoception and proprioception sensory functions was uncovered. Specific bursting units (Inter Spike Interval of 30-70ms) were observed most frequently from the tibial fascicle during bipedal locomotion. Chapter 4

  9. Compensatory recruitment of neural resources in chronic alcoholism.

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    Chanraud, Sandra; Sullivan, Edith V

    2014-01-01

    Functional recovery occurs with sustained sobriety, but the neural mechanisms enabling recovery are only now emerging. Theories about promising mechanisms involve concepts of neuroadaptation, where excessive alcohol consumption results in untoward structural and functional brain changes which are subsequently candidates for reversal with sobriety. Views on functional adaptation in chronic alcoholism have expanded with results from neuroimaging studies. Here, we first describe and define the concept of neuroadaptation according to emerging theories based on the growing literature in aging-related cognitive functioning. Then we describe findings as they apply to chronic alcoholism and factors that could influence compensation, such as functional brain reserve and the integrity of brain structure. Finally, we review brain plasticity based on physiologic mechanisms that could underlie mechanisms of neural compensation. Where possible, we provide operational criteria to define functional and neural compensation.

  10. Digital mammography with multi-electrode ionization chamber

    CERN Document Server

    Groshev, V R; Nifontov, V I; Pishenuok, S M; Samsonov, A A; Shekhtman, L I; Telnov, V I

    2000-01-01

    For viewing micro-calcifications smaller than 100 mu m investigation of image formation in mammography shows that a significant dose to the patient is imperative. We propose a novel one-dimensional Multi- electrode Ionisation Chamber (MIC), with high spatial resolution, and lowered doses. In this work, first results from a prototype are presented. High spatial resolution is demonstrated working with Xe mixture at high pressure. An addition of a Gas Electron Multiplier (GEM) allowed an improvement in sensitivity up to almost single- photon level. (8 refs).

  11. Psychological Processing in Chronic Pain: A Neural Systems Approach

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    Simons, Laura; Elman, Igor; Borsook, David

    2014-01-01

    Our understanding of chronic pain involves complex brain circuits that include sensory, emotional, cognitive and interoceptive processing. The feed-forward interactions between physical (e.g., trauma) and emotional pain and the consequences of altered psychological status on the expression of pain have made the evaluation and treatment of chronic pain a challenge in the clinic. By understanding the neural circuits involved in psychological processes, a mechanistic approach to the implementation of psychology-based treatments may be better understood. In this review we evaluate some of the principle processes that may be altered as a consequence of chronic pain in the context of localized and integrated neural networks. These changes are ongoing, vary in their magnitude, and their hierarchical manifestations, and may be temporally and sequentially altered by treatments, and all contribute to an overall pain phenotype. Furthermore, we link altered psychological processes to specific evidence-based treatments to put forth a model of pain neuroscience psychology. PMID:24374383

  12. Neural Control of Chronic Stress Adaptation

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    James eHerman

    2013-08-01

    Full Text Available Stress initiates adaptive processes that allow the organism to physiologically cope with prolonged or intermittent exposure to real or perceived threats. A major component of this response is repeated activation of glucocorticoid secretion by the hypothalamo-pituitary-adrenocortical (HPA axis, which promotes redistribution of energy in a wide range of organ systems, including the brain. Prolonged or cumulative increases in glucocorticoid secretion can reduce benefits afforded by enhanced stress reactivity and eventually become maladaptive. The long-term impact of stress is kept in check by the process of habituation, which reduces HPA axis responses upon repeated exposure to homotypic stressors and likely limits deleterious actions of prolonged glucocorticoid secretion. Habituation is regulated by limbic stress-regulatory sites, and is at least in part glucocorticoid feedback-dependent. Chronic stress also sensitizes reactivity to new stimuli. While sensitization may be important in maintaining response flexibility in response to new threats, it may also add to the cumulative impact of glucocorticoids on the brain and body. Finally, unpredictable or severe stress exposure may cause long-term and lasting dysregulation of the HPA axis, likely due to altered limbic control of stress effector pathways. Stress-related disorders, such as depression and PTSD, are accompanied by glucocorticoid imbalances and structural/ functional alterations in limbic circuits that resemble those seen following chronic stress, suggesting that inappropriate processing of stressful information may be part of the pathological process.

  13. Neural Plasticity in Common Forms of Chronic Headaches

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    Lai, Tzu-Hsien; Protsenko, Ekaterina; Cheng, Yu-Chen; Loggia, Marco L.; Coppola, Gianluca; Chen, Wei-Ta

    2015-01-01

    Headaches are universal experiences and among the most common disorders. While headache may be physiological in the acute setting, it can become a pathological and persistent condition. The mechanisms underlying the transition from episodic to chronic pain have been the subject of intense study. Using physiological and imaging methods, researchers have identified a number of different forms of neural plasticity associated with migraine and other headaches, including peripheral and central sensitization, and alterations in the endogenous mechanisms of pain modulation. While these changes have been proposed to contribute to headache and pain chronification, some findings are likely the results of repetitive noxious stimulation, such as atrophy of brain areas involved in pain perception and modulation. In this review, we provide a narrative overview of recent advances on the neuroimaging, electrophysiological and genetic aspects of neural plasticity associated with the most common forms of chronic headaches, including migraine, cluster headache, tension-type headache, and medication overuse headache. PMID:26366304

  14. Neural Plasticity in Common Forms of Chronic Headaches

    Directory of Open Access Journals (Sweden)

    Tzu-Hsien Lai

    2015-01-01

    Full Text Available Headaches are universal experiences and among the most common disorders. While headache may be physiological in the acute setting, it can become a pathological and persistent condition. The mechanisms underlying the transition from episodic to chronic pain have been the subject of intense study. Using physiological and imaging methods, researchers have identified a number of different forms of neural plasticity associated with migraine and other headaches, including peripheral and central sensitization, and alterations in the endogenous mechanisms of pain modulation. While these changes have been proposed to contribute to headache and pain chronification, some findings are likely the results of repetitive noxious stimulation, such as atrophy of brain areas involved in pain perception and modulation. In this review, we provide a narrative overview of recent advances on the neuroimaging, electrophysiological and genetic aspects of neural plasticity associated with the most common forms of chronic headaches, including migraine, cluster headache, tension-type headache, and medication overuse headache.

  15. Conformally encapsulated multi-electrode arrays with seamless insulation

    Energy Technology Data Exchange (ETDEWEB)

    Tabada, Phillipe J.; Shah, Kedar G.; Tolosa, Vanessa; Pannu, Satinderall S.; Tooker, Angela; Delima, Terri; Sheth, Heeral; Felix, Sarah

    2016-11-22

    Thin-film multi-electrode arrays (MEA) having one or more electrically conductive beams conformally encapsulated in a seamless block of electrically insulating material, and methods of fabricating such MEAs using reproducible, microfabrication processes. One or more electrically conductive traces are formed on scaffold material that is subsequently removed to suspend the traces over a substrate by support portions of the trace beam in contact with the substrate. By encapsulating the suspended traces, either individually or together, with a single continuous layer of an electrically insulating material, a seamless block of electrically insulating material is formed that conforms to the shape of the trace beam structure, including any trace backings which provide suspension support. Electrical contacts, electrodes, or leads of the traces are exposed from the encapsulated trace beam structure by removing the substrate.

  16. Discrepancies between Multi-Electrode LFP and CSD Phase-Patterns: A Forward Modeling Study.

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    Hindriks, Rikkert; Arsiwalla, Xerxes D; Panagiotaropoulos, Theofanis; Besserve, Michel; Verschure, Paul F M J; Logothetis, Nikos K; Deco, Gustavo

    2016-01-01

    Multi-electrode recordings of local field potentials (LFPs) provide the opportunity to investigate the spatiotemporal organization of neural activity on the scale of several millimeters. In particular, the phases of oscillatory LFPs allow studying the coordination of neural oscillations in time and space and to tie it to cognitive processing. Given the computational roles of LFP phases, it is important to know how they relate to the phases of the underlying current source densities (CSDs) that generate them. Although CSDs and LFPs are distinct physical quantities, they are often (implicitly) identified when interpreting experimental observations. That this identification is problematic is clear from the fact that LFP phases change when switching to different electrode montages, while the underlying CSD phases remain unchanged. In this study we use a volume-conductor model to characterize discrepancies between LFP and CSD phase-patterns, to identify the contributing factors, and to assess the effect of different electrode montages. Although we focus on cortical LFPs recorded with two-dimensional (Utah) arrays, our findings are also relevant for other electrode configurations. We found that the main factors that determine the discrepancy between CSD and LFP phase-patterns are the frequency of the neural oscillations and the extent to which the laminar CSD profile is balanced. Furthermore, the presence of laminar phase-differences in cortical oscillations, as commonly observed in experiments, precludes identifying LFP phases with those of the CSD oscillations at a given cortical depth. This observation potentially complicates the interpretation of spike-LFP coherence and spike-triggered LFP averages. With respect to reference strategies, we found that the average-reference montage leads to larger discrepancies between LFP and CSD phases as compared with the referential montage, while the Laplacian montage reduces these discrepancies. We therefore advice to conduct

  17. Discrepancies between multi-electrode LFP and CSD phase-patterns: A forward modeling study.

    Directory of Open Access Journals (Sweden)

    Rikkert Hindriks

    2016-07-01

    Full Text Available Multi-electrode recordings of local field potentials (LFP's provide the opportunity to investigate the spatiotemporal organization of neural activity on the scale of several millimeters. In particular, the phases of oscillatory LFP's allow studying the coordination of neural oscillations in time and space and to tie it to cognitive processing. Given the computational roles of LFP phases, it is important to know how they relate to the phases of the underlying current source densities (CSD's that generate them.Although CSD's and LFP's are distinct physical quantities, they are often (implicitly identified when interpreting experimental observations.That this identification is problematic is clear from the fact that LFP phases change when switching to different electrode montages, while the underlying CSD phases remain unchanged. In this study we use a volume-conductor model to characterize discrepancies between LFP and CSD phase-patterns, to identify the contributing factors, and to assessthe effect of different electrode montages. Although we focus on cortical LFP's recorded with two-dimensional (Utah arrays, our findings are also relevant for other electrode configurations. We found that the main factors that determine the discrepancy between CSD and LFP phase-patterns are the frequency of the neural oscillations and the extent to which the laminar CSD profile is balanced. Furthermore, the presence of laminar phase-differences in cortical oscillations, as commonly observed in experiments, precludes identifying LFP phases with those of the oscillations at a given cortical depth. This observation potentially complicates the interpretation of spike-LFP coherence and spike-triggered CSD averages. With respect to reference strategies, we found that the average-reference montage leads to larger discrepancies between LFP and CSD phases as compared with the referential montage, while the Laplacian montage reduces these discrepancies.

  18. Fibre-selective recording from the peripheral nerves of frogs using a multi-electrode cuff

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    Schuettler, Martin; Donaldson, Nick; Seetohul, Vipin; Taylor, John

    2013-06-01

    Objective. We investigate the ability of the method of velocity selective recording (VSR) to determine the fibre types that contribute to a compound action potential (CAP) propagating along a peripheral nerve. Real-time identification of the active fibre types by determining the direction of action potential propagation (afferent or efferent) and velocity might allow future neural prostheses to make better use of biological sensor signals and provide a new and simple tool for use in fundamental neuroscience. Approach. Fibre activity was recorded from explanted Xenopus Laevis frog sciatic nerve using a single multi-electrode cuff that records whole nerve activity with 11 equidistant ring-shaped electrodes. The recorded signals were amplified, delayed against each other with variable delay times, added and band-pass filtered. Finally, the resulting amplitudes were measured. Main Result. Our experiments showed that electrically evoked frog CAP was dominated by two fibre populations, propagating at around 20 and 40 m/s, respectively. The velocity selectivity, i.e. the ability of the system to discriminate between individual populations was increased by applying band-pass filtering. The method extracted an entire velocity spectrum from a 10 ms CAP recording sample in real time. Significance. Unlike the techniques introduced in the 1970s and subsequently, VSR requires only a single nerve cuff and does not require averaging to provide velocity spectral information. This makes it potentially suitable for the generation of highly-selective real-time control-signals for future neural prostheses. In our study, electrically evoked CAPs were analysed and it remains to be proven whether the method can reliably classify physiological nerve traffic. The work presented here was carried out at the laboratories of the Implanted Devices Group, Department of Medical Physics and Bioengineering, University College London, UK.

  19. Chronic stress disrupts neural coherence between cortico-limbic structures

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    João Filipe Oliveira

    2013-02-01

    Full Text Available Chronic stress impairs cognitive function, namely on tasks that rely on the integrity of cortico-limbic networks. To unravel the functional impact of progressive stress in cortico-limbic networks we measured neural activity and spectral coherences between the ventral hippocampus (vHIP and the medial prefrontal cortex (mPFC in rats subjected to short term (STS and chronic unpredictable stress (CUS. CUS exposure consistently disrupted the spectral coherence between both areas for a wide range of frequencies, whereas STS exposure failed to trigger such effect. The chronic stress-induced coherence decrease correlated inversely with the vHIP power spectrum, but not with the mPFC power spectrum, which supports the view that hippocampal dysfunction is the primary event after stress exposure. Importantly, we additionally show that the variations in vHIP-to-mPFC coherence and power spectrum in the vHIP correlated with stress-induced behavioral deficits in a spatial reference memory task. Altogether, these findings result in an innovative readout to measure, and follow, the functional events that underlie the stress-induced reference memory impairments.

  20. Commercialisation of CMOS integrated circuit technology in multi-electrode arrays for neuroscience and cell-based biosensors.

    Science.gov (United States)

    Graham, Anthony H D; Robbins, Jon; Bowen, Chris R; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented.

  1. Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Chris R. Bowen

    2011-05-01

    Full Text Available The adaptation of standard integrated circuit (IC technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented.

  2. Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors

    Science.gov (United States)

    Graham, Anthony H. D.; Robbins, Jon; Bowen, Chris R.; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented. PMID:22163884

  3. Network dynamics of cultured hippocampal neurons in a multi-electrode array

    Science.gov (United States)

    Taguchi, Takahisa; Kudoh, Suguru N.

    2005-02-01

    The neurons in dissociation culture autonomously re-organized their functional neuronal networks, after the process for elongating neurites and establishing synaptic connections. The spatio-temporal patterns of activity in the networks might be a reflection of functional neuron assemblies. The functional connections were dynamically modified by synaptic potentiation and the process may be required for reorganization of the functional group of neurons. Such neuron assemblies are critical for information processing in brain. To visualize the functional connections between neurons, we have analyzed the autonomous activity of synaptically induced action potentials in the living neuronal networks on a multi-electrode array, using "connection map analysis" that we developed for this purpose. Moreover, we designed aan original wide area covering electrode array and succeeded in recording spontaneous action potentials from wider area than commercial multi electrode arrays.

  4. Carbon nanotube based multi electrode arrays for neuronal interfacing: progress and prospects

    OpenAIRE

    Yael eHanein; Lilach eBareket-Keren

    2013-01-01

    Carbon nanotube coatings have been demonstrated over the past several years as a promising material for neuronal interfacing applications. In particular, in the realm of neuronal implants, carbon nanotubes have major advantages owing to their unique mechanical and electrical properties. Here we review recent investigations utilizing carbon nanotubes in neuro-interfacing applications. Cell adhesion, neuronal engineering and multi electrode recordings with carbon nanotubes are described. We als...

  5. Numerical simulation research on multi-electrodes resistivity imaging survey array

    Institute of Scientific and Technical Information of China (English)

    Jianjun NIU; Xiaopei ZHANG; Lizhi DU

    2008-01-01

    Multi-electrodes Resistivity Imaging Survey (MRIS) is an array method of electrical survey. In practice how to choose a reasonable array is the key to get reliable survey results. Based on four methods of MRIS such as Wenner, Schlumberger, Pole-pole and Dipole-dipole the authors established the model, by studying the result of the forward numerical simulation modeling and inverse modeling, and analyzed the differences among the different forms of detection devices.

  6. Planar multi-electrode array sensor for localized electrochemical corrosion detection

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    Tormoen, Garth William; Brossia, Christopher Sean

    2014-01-07

    A planarized type of coupled multi-electrode corrosion sensing device. Electrode pads are fabricated on a thin backing, such as a thin film. Each pad has an associated electrical lead for connection to auxiliary electronic circuitry, which may include a resistor associated with each electrical pad. The design permits the device to be easily placed in small crevices or under coatings such as paint.

  7. Step-by-step instructions for retina recordings with perforated multi electrode arrays.

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    Katja Reinhard

    Full Text Available Multi-electrode arrays are a state-of-the-art tool in electrophysiology, also in retina research. The output cells of the retina, the retinal ganglion cells, form a monolayer in many species and are well accessible due to their proximity to the inner retinal surface. This structure has allowed the use of multi-electrode arrays for high-throughput, parallel recordings of retinal responses to presented visual stimuli, and has led to significant new insights into retinal organization and function. However, using conventional arrays where electrodes are embedded into a glass or ceramic plate can be associated with three main problems: (1 low signal-to-noise ratio due to poor contact between electrodes and tissue, especially in the case of strongly curved retinas from small animals, e.g. rodents; (2 insufficient oxygen and nutrient supply to cells located on the bottom of the recording chamber; and (3 displacement of the tissue during recordings. Perforated multi-electrode arrays (pMEAs have been found to alleviate all three issues in brain slice recordings. Over the last years, we have been using such perforated arrays to study light evoked activity in the retinas of various species including mouse, pig, and human. In this article, we provide detailed step-by-step instructions for the use of perforated MEAs to record visual responses from the retina, including spike recordings from retinal ganglion cells and in vitro electroretinograms (ERG. In addition, we provide in-depth technical and methodological troubleshooting information, and show example recordings of good quality as well as examples for the various problems which might be encountered. While our description is based on the specific equipment we use in our own lab, it may also prove useful when establishing retinal MEA recordings with other equipment.

  8. A modular robust control framework for control of movement elicited by multi-electrode intraspinal microstimulation

    Science.gov (United States)

    Roshani, Amir; Erfanian, Abbas

    2016-08-01

    Objective. An important issue in restoring motor function through intraspinal microstimulation (ISMS) is the motor control. To provide a physiologically plausible motor control using ISMS, it should be able to control the individual motor unit which is the lowest functional unit of motor control. By focal stimulation only a small group of motor neurons (MNs) within a motor pool can be activated. Different groups of MNs within a motor pool can potentially be activated without involving adjacent motor pools by local stimulation of different parts of a motor pool via microelectrode array implanted into a motor pool. However, since the system has multiple inputs with single output during multi-electrode ISMS, it poses a challenge to movement control. In this paper, we proposed a modular robust control strategy for movement control, whereas multi-electrode array is implanted into each motor activation pool of a muscle. Approach. The controller was based on the combination of proportional-integral-derivative and adaptive fuzzy sliding mode control. The global stability of the controller was guaranteed. Main results. The results of the experiments on rat models showed that the multi-electrode control can provide a more robust control and accurate tracking performance than a single-electrode control. The control output can be pulse amplitude (pulse amplitude modulation, PAM) or pulse width (pulse width modulation, PWM) of the stimulation signal. The results demonstrated that the controller with PAM provided faster convergence rate and better tracking performance than the controller with PWM. Significance. This work represents a promising control approach to the restoring motor functions using ISMS. The proposed controller requires no prior knowledge about the dynamics of the system to be controlled and no offline learning phase. The proposed control design is modular in the sense that each motor pool has an independent controller and each controller is able to control ISMS

  9. Carbon nanotube based multi electrode arrays for neuronal interfacing: progress and prospects

    Directory of Open Access Journals (Sweden)

    Yael eHanein

    2013-01-01

    Full Text Available Carbon nanotube coatings have been demonstrated over the past several years as a promising material for neuronal interfacing applications. In particular, in the realm of neuronal implants, carbon nanotubes have major advantages owing to their unique mechanical and electrical properties. Here we review recent investigations utilizing carbon nanotubes in neuro-interfacing applications. Cell adhesion, neuronal engineering and multi electrode recordings with carbon nanotubes are described. We also highlight prospective advances in this field, in particular, progress towards flexible, bio-compatible carbon nanotubes technology.

  10. Carbon nanotube multi-electrode array chips for noninvasive real-time measurement of dopamine, action potentials, and postsynaptic potentials.

    Science.gov (United States)

    Suzuki, Ikuro; Fukuda, Mao; Shirakawa, Keiichi; Jiko, Hideyasu; Gotoh, Masao

    2013-11-15

    Multi-electrode arrays (MEAs) can be used for noninvasive, real-time, and long-term recording of electrophysiological activity and changes in the extracellular chemical microenvironment. Neural network organization, neuronal excitability, synaptic and phenotypic plasticity, and drug responses may be monitored by MEAs, but it is still difficult to measure presynaptic activity, such as neurotransmitter release, from the presynaptic bouton. In this study, we describe the development of planar carbon nanotube (CNT)-MEA chips that can measure both the release of the neurotransmitter dopamine as well as electrophysiological responses such as field postsynaptic potentials (fPSPs) and action potentials (APs). These CNT-MEA chips were fabricated by electroplating the indium-tin oxide (ITO) microelectrode surfaces. The CNT-plated ITO electrode exhibited electrochemical response, having much higher current density compared with the bare ITO electrode. Chronoamperometric measurements using these CNT-MEA chips detected dopamine at nanomolar concentrations. By placing mouse striatal brain slices on the CNT-MEA chip, we successfully measured synaptic dopamine release from spontaneous firings with a high S/N ratio of 62. Furthermore, APs and fPSPs were measured from cultured hippocampal neurons and slices with high temporal resolution and a 100-fold greater S/N ratio. Our CNT-MEA chips made it possible to measure neurotransmitter dopamine (presynaptic activities), postsynaptic potentials, and action potentials, which have a central role in information processing in the neuronal network. CNT-MEA chips could prove useful for in vitro studies of stem cell differentiation, drug screening and toxicity, synaptic plasticity, and pathogenic processes involved in epilepsy, stroke, and neurodegenerative diseases.

  11. Optogenetic modulation and multi-electrode analysis of cerebellar networks in vivo.

    Directory of Open Access Journals (Sweden)

    Wolfgang Kruse

    Full Text Available The firing patterns of cerebellar Purkinje cells (PCs, as the sole output of the cerebellar cortex, determine and tune motor behavior. PC firing is modulated by various inputs from different brain regions and by cell-types including granule cells (GCs, climbing fibers and inhibitory interneurons. To understand how signal integration in PCs occurs and how subtle changes in the modulation of PC firing lead to adjustment of motor behaviors, it is important to precisely record PC firing in vivo and to control modulatory pathways in a spatio-temporal manner. Combining optogenetic and multi-electrode approaches, we established a new method to integrate light-guides into a multi-electrode system. With this method we are able to variably position the light-guide in defined regions relative to the recording electrode with micrometer precision. We show that PC firing can be precisely monitored and modulated by light-activation of channelrhodopsin-2 (ChR2 expressed in PCs, GCs and interneurons. Thus, this method is ideally suited to investigate the spatio/temporal modulation of PCs in anesthetized and in behaving mice.

  12. Optogenetic Modulation and Multi-Electrode Analysis of Cerebellar Networks In Vivo

    Science.gov (United States)

    Kruse, Wolfgang; Krause, Martin; Aarse, Janna; Mark, Melanie D.; Manahan-Vaughan, Denise; Herlitze, Stefan

    2014-01-01

    The firing patterns of cerebellar Purkinje cells (PCs), as the sole output of the cerebellar cortex, determine and tune motor behavior. PC firing is modulated by various inputs from different brain regions and by cell-types including granule cells (GCs), climbing fibers and inhibitory interneurons. To understand how signal integration in PCs occurs and how subtle changes in the modulation of PC firing lead to adjustment of motor behaviors, it is important to precisely record PC firing in vivo and to control modulatory pathways in a spatio-temporal manner. Combining optogenetic and multi-electrode approaches, we established a new method to integrate light-guides into a multi-electrode system. With this method we are able to variably position the light-guide in defined regions relative to the recording electrode with micrometer precision. We show that PC firing can be precisely monitored and modulated by light-activation of channelrhodopsin-2 (ChR2) expressed in PCs, GCs and interneurons. Thus, this method is ideally suited to investigate the spatio/temporal modulation of PCs in anesthetized and in behaving mice. PMID:25144735

  13. High-density percutaneous chronic connector for neural prosthetics

    Science.gov (United States)

    Shah, Kedar G.; Bennett, William J.; Pannu, Satinderpall S.

    2015-09-22

    A high density percutaneous chronic connector, having first and second connector structures each having an array of magnets surrounding a mounting cavity. A first electrical feedthrough array is seated in the mounting cavity of the first connector structure and a second electrical feedthrough array is seated in the mounting cavity of the second connector structure, with a feedthrough interconnect matrix positioned between a top side of the first electrical feedthrough array and a bottom side of the second electrical feedthrough array to electrically connect the first electrical feedthrough array to the second electrical feedthrough array. The two arrays of magnets are arranged to attract in a first angular position which connects the first and second connector structures together and electrically connects the percutaneously connected device to the external electronics, and to repel in a second angular position to facilitate removal of the second connector structure from the first connector structure.

  14. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.

  15. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation. PMID:26795421

  16. Chronic Childhood Peer Rejection is Associated with Heightened Neural Responses to Social Exclusion During Adolescence.

    Science.gov (United States)

    Will, Geert-Jan; van Lier, Pol A C; Crone, Eveline A; Güroğlu, Berna

    2016-01-01

    This functional Magnetic Resonance Imaging (fMRI) study examined subjective and neural responses to social exclusion in adolescents (age 12-15) who either had a stable accepted (n = 27; 14 males) or a chronic rejected (n = 19; 12 males) status among peers from age 6 to 12. Both groups of adolescents reported similar increases in distress after being excluded in a virtual ball-tossing game (Cyberball), but adolescents with a history of chronic peer rejection showed higher activity in brain regions previously linked to the detection of, and the distress caused by, social exclusion. Specifically, compared with stably accepted adolescents, chronically rejected adolescents displayed: 1) higher activity in the dorsal anterior cingulate cortex (dACC) during social exclusion and 2) higher activity in the dACC and anterior prefrontal cortex when they were incidentally excluded in a social interaction in which they were overall included. These findings demonstrate that chronic childhood peer rejection is associated with heightened neural responses to social exclusion during adolescence, which has implications for understanding the processes through which peer rejection may lead to adverse effects on mental health over time.

  17. Chronic pain resolution after a lucid dream: a case for neural plasticity?

    Science.gov (United States)

    Zappaterra, Mauro; Jim, Lysander; Pangarkar, Sanjog

    2014-03-01

    Chronic pain is often managed using a multidisciplinary, biopsychosocial approach. Interventions targeting the biological, psychological, and social aspects of both the patient and the pain have been demonstrated to provide objective and subjective improvement in chronic pain symptoms. The mechanism by which pain attenuation occurs after these interventions remains to be elucidated. While there is a relatively large body of empirical literature suggesting that functional and structural changes in the peripheral and central nervous systems are key in the development and maintenance of chronic pain states, less is known about changes that take place in the nervous system as a whole after biopsychosocial interventions. Using as a model the unique case of Mr. S, a patient suffering with chronic pain for 22 years who experienced a complete resolution of pain after a lucid dream following 2 years of biopsychosocial treatments, we postulate that central nervous system (CNS) reorganization (i.e., neural plasticity) serves as a possible mechanism for the therapeutic benefit of multidisciplinary treatments, and may set a neural framework for healing, in this case via a lucid dream.

  18. The Neural Correlates of Chronic Symptoms of Vertigo Proneness in Humans.

    Directory of Open Access Journals (Sweden)

    Ola Alsalman

    Full Text Available Vestibular signals are of significant importance for variable functions including gaze stabilization, spatial perception, navigation, cognition, and bodily self-consciousness. The vestibular network governs functions that might be impaired in patients affected with vestibular dysfunction. It is currently unclear how different brain regions/networks process vestibular information and integrate the information into a unified spatial percept related to somatosensory awareness and whether people with recurrent balance complaints have a neural signature as a trait affecting their development of chronic symptoms of vertigo. Pivotal evidence points to a vestibular-related brain network in humans that is widely distributed in nature. By using resting state source localized electroencephalography in non-vertiginous state, electrophysiological changes in activity and functional connectivity of 23 patients with balance complaints where chronic symptoms of vertigo and dizziness are among the most common reported complaints are analyzed and compared to healthy subjects. The analyses showed increased alpha2 activity within the posterior cingulate cortex and the precuneues/cuneus and reduced beta3 and gamma activity within the pregenual and subgenual anterior cingulate cortex for the subjects with balance complaints. These electrophysiological variations were correlated with reported chronic symptoms of vertigo intensity. A region of interest analysis found reduced functional connectivity for gamma activity within the vestibular cortex, precuneus, frontal eye field, intra-parietal sulcus, orbitofrontal cortex, and the dorsal anterior cingulate cortex. In addition, there was a positive correlation between chronic symptoms of vertigo intensity and increased alpha-gamma nesting in the left frontal eye field. When compared to healthy subjects, there is evidence of electrophysiological changes in the brain of patients with balance complaints even outside chronic

  19. Forward Modeling of Different Types of Landslides with Multi-electrode Electric Method

    Institute of Scientific and Technical Information of China (English)

    GuoXiujun; HuangXiaoyu; JiaYonggang

    2005-01-01

    Multi-electrode Electric Method (MEM) is an effective tool in landslide survey. A suitable working scheme in-situ and the corresponding data interpretation approach are the fundamentals for obtaining believable results. Finite element 2D forward modeling was conducted on four types of standard electric models; respectively named the homogeneous soil landside, bedding landside, sliderock landside, and beveling landside; under the utilizations of four different types of electrode arrays;respectively namely the Wenner array, Schlumberger array, dipole-dipole array and pole-pole array.The capacities of different arrays and the resistivity responses of different types of sliding faces were determined based on the resultant standard electric profiles. An innovative data processing procedure called the ratio parameter method was proposed for locating sliding faces under complex geological conditions. A series of case histories for landside survey were given.

  20. An Investigation of Groundwater Flow on a Coastal Barrier using Multi Electrode Profiling

    DEFF Research Database (Denmark)

    Poulsen, Søren Erbs; Christensen, Steen; Rasmussen, Keld Rømer;

    2008-01-01

    probes, having closely spaced electrodes from above the groundwater table to a depth of 5 m below sea level, have been installed and tested. Using this system we will monitor resistivity and thus groundwater salinity variations in space and time. Analyzing the measurements using density dependent......Preliminary geophysical and hydrogeological investigations indicate that multi-electrode profiling (MEP) can be used to monitor groundwater salinity on a coastal barrier where a shallow thin aquifer discharges to the North Sea. A monitoring system including five groups of piezometers and five MEP...... groundwater modeling we hope to be able to quantify how time varying recharge, tides, and storms hitting the barrier affect groundwater flow and discharge to the sea. At the conference we will present monitoring results from the winter and spring 2008....

  1. Preventive Healthcare: A Neural Network Analysis of Behavioral Habits and Chronic Diseases

    Directory of Open Access Journals (Sweden)

    Viju Raghupathi

    2017-02-01

    Full Text Available The research aims to explore the association between behavioral habits and chronic diseases, and to identify a portfolio of risk factors for preventive healthcare. The data is taken from the Behavioral Risk Factor Surveillance System (BRFSS database of the Centers for Disease Control and Prevention, for the year 2012. Using SPSS Modeler, we deploy neural networks to identify strong positive and negative associations between certain chronic diseases and behavioral habits. The data for 475,687 records from BRFS database included behavioral habit variables of consumption of soda and fruits/vegetables, alcohol, smoking, weekly working hours, and exercise; chronic disease variables of heart attack, stroke, asthma, and diabetes; and demographic variables of marital status, income, and age. Our findings indicate that with chronic conditions, behavioral habits of physical activity and fruit and vegetable consumption are negatively associated; soda, alcohol, and smoking are positively associated; and income and age are positively associated. We contribute to individual and national preventive healthcare by offering a portfolio of significant behavioral risk factors that enable individuals to make lifestyle changes and governments to frame campaigns and policies countering chronic conditions and promoting public health.

  2. Neural correlates of retaliatory and prosocial reactions to social exclusion: Associations with chronic peer rejection

    Directory of Open Access Journals (Sweden)

    Geert-Jan Will

    2016-06-01

    Full Text Available Social exclusion is a distressing experience and can lead to both retaliatory and prosocial reactions toward the sources of exclusion. The way people react to social exclusion has been hypothesized to be shaped through chronic exposure to peer rejection. This functional Magnetic Resonance Imaging study examined associations between chronic peer rejection and retaliatory (i.e. punishing and prosocial (i.e. forgiving reactions to social exclusion and the neural processes underlying them. Chronically rejected (n = 19 and stably highly accepted adolescents (n = 27 distributed money between themselves and unknown others who previously included or excluded them in a virtual ball-tossing game (Cyberball. Decreasing the excluders’ monetary profits (i.e., punishment was associated with increased activity in the ventral striatum, dorsolateral prefrontal cortex (PFC and parietal cortex in both groups. Compared to stably highly accepted adolescents, chronically rejected adolescents exhibited higher activity in the dorsal striatum and lateral prefrontal cortex – brain regions implicated in cognitive control – when they refrained from punishment and shared their money equally with (i.e. forgave the excluders. These results provide insights into processes that might underlie the maintenance of peer rejection across development, such as difficulties controlling the urge to retaliate after exclusion.

  3. Neural correlates of retaliatory and prosocial reactions to social exclusion: Associations with chronic peer rejection.

    Science.gov (United States)

    Will, Geert-Jan; Crone, Eveline A; van Lier, Pol A C; Güroğlu, Berna

    2016-06-01

    Social exclusion is a distressing experience and can lead to both retaliatory and prosocial reactions toward the sources of exclusion. The way people react to social exclusion has been hypothesized to be shaped through chronic exposure to peer rejection. This functional Magnetic Resonance Imaging study examined associations between chronic peer rejection and retaliatory (i.e. punishing) and prosocial (i.e. forgiving) reactions to social exclusion and the neural processes underlying them. Chronically rejected (n=19) and stably highly accepted adolescents (n=27) distributed money between themselves and unknown others who previously included or excluded them in a virtual ball-tossing game (Cyberball). Decreasing the excluders' monetary profits (i.e., punishment) was associated with increased activity in the ventral striatum, dorsolateral prefrontal cortex (PFC) and parietal cortex in both groups. Compared to stably highly accepted adolescents, chronically rejected adolescents exhibited higher activity in the dorsal striatum and lateral prefrontal cortex - brain regions implicated in cognitive control - when they refrained from punishment and shared their money equally with (i.e. forgave) the excluders. These results provide insights into processes that might underlie the maintenance of peer rejection across development, such as difficulties controlling the urge to retaliate after exclusion.

  4. An approach to the diagnosis of metabolic syndrome by the multi-electrode impedance method

    Science.gov (United States)

    Furuya, N.; Sakamoto, K.; Kanai, H.

    2010-04-01

    It is well known that metabolic syndrome can induce myocardial infarction and cerebral infarction. So, it is very important to measure the visceral fat volume. In the electric impedance method, information in the vicinity of the electrodes is strongly reflected. Therefore, we propose a new multi-electrode arrangement method based on the impedance sensitivity theorem to measure the visceral fat volume. This electrode arrangement is designed to enable high impedance sensitivity in the visceral and subcutaneous fat regions. Currents are simultaneously applied to several current electrodes on the body surface, and one voltage electrode pair is arranged on the body surface near the organ of interest to obtain the visceral fat information and another voltage electrode pair is arranged on the body surface near the current electrodes to obtain the subcutaneous fat information. A simulation study indicates that by weighting the impedance sensitivity distribution, as in our method, a high-sensitivity region in the visceral and the subcutaneous fat regions can be formed. In addition, it was confirmed that the visceral fat volume can be estimated by the measured impedance data.

  5. Unified selective sorting approach to analyse multi-electrode extracellular data

    Science.gov (United States)

    Veerabhadrappa, R.; Lim, C. P.; Nguyen, T. T.; Berk, M.; Tye, S. J.; Monaghan, P.; Nahavandi, S.; Bhatti, A.

    2016-06-01

    Extracellular data analysis has become a quintessential method for understanding the neurophysiological responses to stimuli. This demands stringent techniques owing to the complicated nature of the recording environment. In this paper, we highlight the challenges in extracellular multi-electrode recording and data analysis as well as the limitations pertaining to some of the currently employed methodologies. To address some of the challenges, we present a unified algorithm in the form of selective sorting. Selective sorting is modelled around hypothesized generative model, which addresses the natural phenomena of spikes triggered by an intricate neuronal population. The algorithm incorporates Cepstrum of Bispectrum, ad hoc clustering algorithms, wavelet transforms, least square and correlation concepts which strategically tailors a sequence to characterize and form distinctive clusters. Additionally, we demonstrate the influence of noise modelled wavelets to sort overlapping spikes. The algorithm is evaluated using both raw and synthesized data sets with different levels of complexity and the performances are tabulated for comparison using widely accepted qualitative and quantitative indicators.

  6. Spiral Ganglion Neuron Explant Culture and Electrophysiology on Multi Electrode Arrays.

    Science.gov (United States)

    Hahnewald, Stefan; Roccio, Marta; Tscherter, Anne; Streit, Jürg; Ambett, Ranjeeta; Senn, Pascal

    2016-10-19

    Spiral ganglion neurons (SGNs) participate in the physiological process of hearing by relaying signals from sensory hair cells to the cochlear nucleus in the brain stem. Loss of hair cells is a major cause of sensory hearing loss. Prosthetic devices such as cochlear implants function by bypassing lost hair cells and directly stimulating SGNs electrically, allowing for restoration of hearing in deaf patients. The performance of these devices depends on the functionality of SGNs, the implantation procedure and on the distance between the electrodes and the auditory neurons. We hypothesized, that reducing the distance between the SGNs and the electrode array of the implant would allow for improved stimulation and frequency resolution, with the best results in a gapless position. Currently we lack in vitro culture systems to study, modify and optimize the interaction between auditory neurons and electrode arrays and characterize their electrophysiological response. To address these issues, we developed an in vitro bioassay using SGN cultures on a planar multi electrode array (MEA). With this method we were able to perform extracellular recording of the basal and electrically induced activity of a population of spiral ganglion neurons. We were also able to optimize stimulation protocols and analyze the response to electrical stimuli as a function of the electrode distance. This platform could also be used to optimize electrode features such as surface coatings.

  7. Gene electrotransfer into skin using noninvasive multi-electrode array for vaccination and wound healing.

    Science.gov (United States)

    Kos, Spela; Vanvarenberg, Kevin; Dolinsek, Tanja; Cemazar, Maja; Jelenc, Jure; Préat, Véronique; Sersa, Gregor; Vandermeulen, Gaëlle

    2017-04-01

    Skin is an attractive target for gene electrotransfer due to its easy accessibility and its interesting immune properties. Since electrodes are often invasive and frequently induce discomfort during pulse application, there is a fundamental need for non-invasive electrodes for skin delivery. We developed circular pin non-invasive multi-electrode array (MEA), suitable for different clinical applications. MEA was first employed to deliver a luciferase reporter gene. Then, it was used to deliver a DNA vaccine coding for ovalbumin or a plasmid encoding hCAP-18/LL-37 for promoting wound healing. The results demonstrated a strong gene expression and an efficient delivery of both, DNA vaccine and wound healing agent, dependent on the pulses applied. The use of MEA to deliver the ovalbumin plasmid demonstrated a strong immune response, as evidenced by the presence of antibodies in sera, the IFN-gamma response and the delayed tumor growth when the mice were subsequently challenged with B16-OVA cells. The delivery of a plasmid encoding hCAP-18/LL-37 significantly accelerated wound closure. The easy applicability and non-invasiveness of MEA make it suitable for various clinical applications that require gene electrotransfer to skin. Specifically, by adapting electric pulses to the expected action of a transgene, non-invasive MEA can be employed either for vaccination or for wound healing.

  8. Visualizing transplanted muscle flaps using minimally invasive multi-electrode bioimpedance spectroscopy

    Science.gov (United States)

    Gordon, R.; Zorkova, V.; Min, M.; Rätsep, I.

    2010-04-01

    We describe here an imaging system that uses bioimpedance spectroscopy with multi-electrode array to indicate the state of muscle flap regions under the array. The system is able to differentiate between different health states in the tissue and give early information about the location and size of ischemic sub-regions. The array will be 4*8 electrodes with the spacing of 5mm between the electrodes (the number of electrodes and the spacing may vary). The electrodes are minimally invasive short stainless steel needles, that penetrate 0.3 mm into the tissue with the goal of achieving a wet electric contact. We combine 32 configurations of 4-electrode multi-frequency impedance measurements to derive a health-state map for the transplanted flap. The imaging method is tested on a model consisting of 2 tissues and FEM software (Finite Element Method -COMSOL Multiphysics based) is used to conduct the measurements virtually. Dedicated multichannel bioimpedance measurement equipment has already been developed and tested, that cover the frequency range from 100 Hz to 1 MHz.

  9. All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters

    CERN Document Server

    Picollo, F; Bernardi, E; Plaitano, M; Franchino, C; Gosso, S; Pasquarelli, A; Carbone, E; Olivero, P; Carabelli, V

    2016-01-01

    We report on the ion beam fabrication of all-carbon multi electrode arrays (MEAs) based on 16 graphitic micro-channels embedded in single-crystal diamond (SCD) substrates. The fabricated SCD-MEAs are systematically employed for the in vitro simultaneous amperometric detection of the secretory activity from populations of chromaffin cells, demonstrating a new sensing approach with respect to standard techniques. The biochemical stability and biocompatibility of the SCD-based device combined with the parallel recording of multi-electrodes array allow: i) a significant time saving in data collection during drug screening and/or pharmacological tests over a large number of cells, ii) the possibility of comparing altered cell functionality among cell populations, and iii) the repeatition of acquisition runs over many cycles with a fully non-toxic and chemically robust bio-sensitive substrate.

  10. Minimum neuron density for synchronized bursts in a rat cortical culture on multi-electrode arrays.

    Science.gov (United States)

    Ito, D; Tamate, H; Nagayama, M; Uchida, T; Kudoh, S N; Gohara, K

    2010-11-24

    To investigate the minimum neuron and neurite densities required for synchronized bursts, we cultured rat cortical neurons on planar multi-electrode arrays (MEAs) at five plating densities (2500, 1000, 500, 250, and 100 cells/mm(2)) using two culture media: Neuron Culture Medium and Dulbecco's Modified Eagle Medium supplemented with serum (DMEM/serum). Long-term recording of spontaneous electrical activity clarified that the cultures exhibiting synchronized bursts required an initial plating density of at least 250 cells/mm(2) for Neuron Culture Medium and 500 cells/mm(2) for DMEM/serum. Immediately after electrical recording, immunocytochemistry of microtubule-associated protein 2 (MAP2) and Neurofilament 200 kD (NF200) was performed directly on MEAs to investigate the actual densities of neurons and neurites forming the networks. Immunofluorescence observation revealed that the construction of complicated neuronal networks required the same initial plating density as for synchronized bursts, and that overly sparse cultures showed significant decreases of neurons and neurites. We also found that the final densities of surviving neurons at 1 month decreased greatly compared with the initial plating densities and became saturated in denser cultures. In addition, the area of neurites and the number of nuclei were saturated in denser cultures. By comparing both the results of electrophysiological recording and immunocytochemical observation, we revealed that there is a minimum threshold of neuron densities that must be met for the exhibition of synchronized bursts. Interestingly, these minimum densities of MAP2-positive final neurons did not differ between the two culture media; the density was approximately 50 neurons/mm(2). This value was obtained in the cultures with the initial plating densities of 250 cells/mm(2) for Neuron Culture Medium and 500 cells/mm(2) for DMEM/serum.

  11. Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

    Science.gov (United States)

    Cai, Yu; Sha, Shuang

    2016-09-01

    This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers.

  12. Comparison of efficacy of neural therapy and physical therapy in chronic low back pain.

    Science.gov (United States)

    Atalay, Nilgun Simsir; Sahin, Fusun; Atalay, Ali; Akkaya, Nuray

    2013-01-01

    The aim of this prospective study was to evaluate the effects of neural therapy, and physical therapy on level of pain, disability, quality of life, and psychological status in patients with chronic low back pain. Patients admitted to the physical therapy and rehabilitation outpatient clinic with the complaint of low back pain of at least 3 months duration. Group 1 (n=27), physical therapy (PT, hotpack, ultrasound, TENS 15 sessions), group 2 (n=33), neural therapy (NT, 1:1 mixture of 20 mg/mL Lidocaine HCl (Jetokain simplex®) and saline for 5 sessions. For pain, Visual Analogue Scale (VAS), for disability Roland Morris Disability Questionnaire (RMDQ), for quality-of-life Nottingham-Health-Profile (NHP), for depression, and anxiety, Hospital Anxiety-Depression Scale (HADS) were used before and after the treatment. Mean age was 47.3±11.32 years, symptom time was 13.78±11.98 months. There were no differences for demographic variables between groups. Significant improvements were detected for VAS, RMDQ, NHP-Pain, NHP-Physical activity, HADS for both of two groups after treatment. In addition to these findings, significant improvements were found for NHP-Energy, NHP-Social isolation in NT group. The differences of pre- and post-treatment values of parameters were evaluated for each group. Although there were no differences for VAS, NHP-sleep, NHP-Emotional reaction, HADS between groups, RMDQ, NHP-Pain, NHP-Physical activity, NHP-Social isolation were higher in NT than PT before treatment, the improvements for these parameters were better in NT than PT. In conclusion both of NT and PT are effective on pain, function, quality of life, anxiety, and depression in patients with chronic low back pain.

  13. Therapeutic activities of engrafted neural stem/precursor cells are not dormant in the chronically injured spinal cord.

    Science.gov (United States)

    Kumamaru, Hiromi; Saiwai, Hirokazu; Kubota, Kensuke; Kobayakawa, Kazu; Yokota, Kazuya; Ohkawa, Yasuyuki; Shiba, Keiichiro; Iwamoto, Yukihide; Okada, Seiji

    2013-08-01

    The transplantation of neural stem/precursor cells (NSPCs) is a promising therapeutic strategy for many neurodegenerative disorders including spinal cord injury (SCI) because it provides for neural replacement or trophic support. This strategy is now being extended to the treatment of chronic SCI patients. However, understanding of biological properties of chronically transplanted NSPCs and their surrounding environments is limited. Here, we performed temporal analysis of injured spinal cords and demonstrated their multiphasic cellular and molecular responses. In particular, chronically injured spinal cords were growth factor-enriched environments, whereas acutely injured spinal cords were enriched by neurotrophic and inflammatory factors. To determine how these environmental differences affect engrafted cells, NSPCs transplanted into acutely, subacutely, and chronically injured spinal cords were selectively isolated by flow cytometry, and their whole transcriptomes were compared by RNA sequencing. This analysis revealed that NSPCs produced many regenerative/neurotrophic molecules irrespective of transplantation timing, and these activities were prominent in chronically transplanted NSPCs. Furthermore, chronically injured spinal cords permitted engrafted NSPCs to differentiate into neurons/oligodendrocytes and provided more neurogenic environment for NSPCs than other environments. Despite these results demonstrate that transplanted NSPCs have adequate capacity in generating neurons/oligodendrocytes and producing therapeutic molecules in chronic SCI microenvironments, they did not improve locomotor function. Our results indicate that failure in chronic transplantation is not due to the lack of therapeutic activities of engrafted NSPCs but the refractory state of chronically injured spinal cords. Environmental modulation, rather modification of transplanting cells, will be significant for successful translation of stem cell-based therapies into chronic SCI patients.

  14. Poly (3, 4-ethylenedioxythiophene)-ionic liquid coating improves neural recording and stimulation functionality of MEAs

    OpenAIRE

    Du, Zhanhong Jeff; Luo, Xiliang; Weaver, Cassandra; Cui, Xinyan Tracy

    2015-01-01

    In vivo multi-electrode arrays (MEAs) can sense electrical signals from a small set of neurons or modulate neural activity through micro-stimulation. Electrode's geometric surface area (GSA) and impedance are important for both unit recording and neural stimulation. Smaller GSA is preferred due to enhanced selectivity of neural signal, but it tends to increase electrode impedance. Higher impedance leads to increased electrical noise and signal loss in single unit neural recording. It also yie...

  15. Response profiles of murine spiral ganglion neurons on multi-electrode arrays

    Science.gov (United States)

    Hahnewald, Stefan; Tscherter, Anne; Marconi, Emanuele; Streit, Jürg; Widmer, Hans Rudolf; Garnham, Carolyn; Benav, Heval; Mueller, Marcus; Löwenheim, Hubert; Roccio, Marta; Senn, Pascal

    2016-02-01

    Objective. Cochlear implants (CIs) have become the gold standard treatment for deafness. These neuroprosthetic devices feature a linear electrode array, surgically inserted into the cochlea, and function by directly stimulating the auditory neurons located within the spiral ganglion, bypassing lost or not-functioning hair cells. Despite their success, some limitations still remain, including poor frequency resolution and high-energy consumption. In both cases, the anatomical gap between the electrode array and the spiral ganglion neurons (SGNs) is believed to be an important limiting factor. The final goal of the study is to characterize response profiles of SGNs growing in intimate contact with an electrode array, in view of designing novel CI devices and stimulation protocols, featuring a gapless interface with auditory neurons. Approach. We have characterized SGN responses to extracellular stimulation using multi-electrode arrays (MEAs). This setup allows, in our view, to optimize in vitro many of the limiting interface aspects between CIs and SGNs. Main results. Early postnatal mouse SGN explants were analyzed after 6-18 days in culture. Different stimulation protocols were compared with the aim to lower the stimulation threshold and the energy needed to elicit a response. In the best case, a four-fold reduction of the energy was obtained by lengthening the biphasic stimulus from 40 μs to 160 μs. Similarly, quasi monophasic pulses were more effective than biphasic pulses and the insertion of an interphase gap moderately improved efficiency. Finally, the stimulation with an external electrode mounted on a micromanipulator showed that the energy needed to elicit a response could be reduced by a factor of five with decreasing its distance from 40 μm to 0 μm from the auditory neurons. Significance. This study is the first to show electrical activity of SGNs on MEAs. Our findings may help to improve stimulation by and to reduce energy consumption of CIs and

  16. Assessment of groundwater salinity in Nellore district using multi-electrode resistivity imaging technique

    Indian Academy of Sciences (India)

    E Chandrasekhar; Deshmukh Ramesh; Trupti Gurav; T K Biswal

    2014-12-01

    Multi-electrode resistivity imaging survey with 48 electrodes was carried out to assess the extent of salinity inland, in the shallow subsurface in Nellore district, Andhra Pradesh, in the Eastern Ghats Mobile Belt (EGMB) region. Resistivity data were recorded using Wenner–Schlumberger configuration at nine sites along a profile of about 55 km in length, laid perpendicular to the coast. An average spacing of 6 km is maintained between each site. Assessment of groundwater salinity in the study area was made by joint interpretation of the two-dimensional (2D) geoelectrical models of all the sites together with the geochemical analysis results of water samples and geology. At sites closer to the coast, 2D geoelectrical models of the subsurface indicate low resistivities (2–50 m) in the depth range from surface up to 15 m. Such low resistivities are due to the high salinity of the groundwater. Geochemical analysis results of water samples at six locations close to the electrical resistivity survey sites also suggest high salinity and high concentrations of total dissolved solids and other chemicals at sites closer to the coast. Away from the coast, the resistivities in the depth range from surface up to 15 m vary in the range of 50–150 m. Accordingly, the chemical analysis of water samples collected at these sites also showed relatively low levels of salinity and salt concentrations in them. However, away from the coast, the resistivities vary in the range of 150–1500 m in the depth range from 20–40 m. While the aquaculture and agriculture activities may contribute to high salinity at the sites closer to the coast, the presence of deep-seated paleochannels aiding in transporting seawater inland, and water–rock interactions are suspected to be the chief causes for notable salinity at places away from the coast at shallow depths. We opine that the high salinity at shallow depths, coupled with the deep-seated paleochannels transporting seawater, could pose

  17. Classification of heavy metal ions present in multi-frequency multi-electrode potable water data using evolutionary algorithm

    Science.gov (United States)

    Karkra, Rashmi; Kumar, Prashant; Bansod, Baban K. S.; Bagchi, Sudeshna; Sharma, Pooja; Krishna, C. Rama

    2016-12-01

    Access to potable water for the common people is one of the most challenging tasks in the present era. Contamination of drinking water has become a serious problem due to various anthropogenic and geogenic events. The paper demonstrates the application of evolutionary algorithms, viz., particle swan optimization and genetic algorithm to 24 water samples containing eight different heavy metal ions (Cd, Cu, Co, Pb, Zn, Ar, Cr and Ni) for the optimal estimation of electrode and frequency to classify the heavy metal ions. The work has been carried out on multi-variate data, viz., single electrode multi-frequency, single frequency multi-electrode and multi-frequency multi-electrode water samples. The electrodes used are platinum, gold, silver nanoparticles and glassy carbon electrodes. Various hazardous metal ions present in the water samples have been optimally classified and validated by the application of Davis Bouldin index. Such studies are useful in the segregation of hazardous heavy metal ions found in water resources, thereby quantifying the degree of water quality.

  18. Long-Term Effects of Chronic Oral Ritalin Administration on Cognitive and Neural Development in Adolescent Wistar Kyoto Rats

    Directory of Open Access Journals (Sweden)

    Jennifer L. Cornish

    2012-09-01

    Full Text Available The diagnosis of Attention Deficit Hyperactivity Disorder (ADHD often results in chronic treatment with psychostimulants such as methylphenidate (MPH, Ritalin®. With increases in misdiagnosis of ADHD, children may be inappropriately exposed to chronic psychostimulant treatment during development. The aim of this study was to assess the effect of chronic Ritalin treatment on cognitive and neural development in misdiagnosed “normal” (Wistar Kyoto, WKY rats and in Spontaneously Hypertensive Rats (SHR, a model of ADHD. Adolescent male animals were treated for four weeks with oral Ritalin® (2 × 2 mg/kg/day or distilled water (dH2O. The effect of chronic treatment on delayed reinforcement tasks (DRT and tyrosine hydroxylase immunoreactivity (TH-ir in the prefrontal cortex was assessed. Two weeks following chronic treatment, WKY rats previously exposed to MPH chose the delayed reinforcer significantly less than the dH2O treated controls in both the DRT and extinction task. MPH treatment did not significantly alter cognitive performance in the SHR. TH-ir in the infralimbic cortex was significantly altered by age and behavioural experience in WKY and SHR, however this effect was not evident in WKY rats treated with MPH. These results suggest that chronic treatment with MPH throughout adolescence in “normal” WKY rats increased impulsive choice and altered catecholamine development when compared to vehicle controls.

  19. Functional connectivity and information flow of the respiratory neural network in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Yu, Lianchun; De Mazancourt, Marine; Hess, Agathe; Ashadi, Fakhrul R; Klein, Isabelle; Mal, Hervé; Courbage, Maurice; Mangin, Laurence

    2016-08-01

    Breathing involves a complex interplay between the brainstem automatic network and cortical voluntary command. How these brain regions communicate at rest or during inspiratory loading is unknown. This issue is crucial for several reasons: (i) increased respiratory loading is a major feature of several respiratory diseases, (ii) failure of the voluntary motor and cortical sensory processing drives is among the mechanisms that precede acute respiratory failure, (iii) several cerebral structures involved in responding to inspiratory loading participate in the perception of dyspnea, a distressing symptom in many disease. We studied functional connectivity and Granger causality of the respiratory network in controls and patients with chronic obstructive pulmonary disease (COPD), at rest and during inspiratory loading. Compared with those of controls, the motor cortex area of patients exhibited decreased connectivity with their contralateral counterparts and no connectivity with the brainstem. In the patients, the information flow was reversed at rest with the source of the network shifted from the medulla towards the motor cortex. During inspiratory loading, the system was overwhelmed and the motor cortex became the sink of the network. This major finding may help to understand why some patients with COPD are prone to acute respiratory failure. Network connectivity and causality were related to lung function and illness severity. We validated our connectivity and causality results with a mathematical model of neural network. Our findings suggest a new therapeutic strategy involving the modulation of brain activity to increase motor cortex functional connectivity and improve respiratory muscles performance in patients. Hum Brain Mapp 37:2736-2754, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  20. Improving Impedance of Implantable Microwire Multi-Electrode Arrays by Ultrasonic Electroplating of Durable Platinum Black

    OpenAIRE

    Desai, Sharanya Arcot; Rolston, John D.; Guo, Liang; Potter, Steve M.

    2010-01-01

    Implantable microelectrode arrays (MEAs) have been a boon for neural stimulation and recording experiments. Commercially available MEAs have high impedances, due to their low surface area and small tip diameters, which are suitable for recording single unit activity. Lowering the electrode impedance, but preserving the small diameter, would provide a number of advantages, including reduced stimulation voltages, reduced stimulation artifacts and improved signal-to-noise ratio. Impedance reduct...

  1. Virtual Electrode Recording Tool for EXtracellular potentials (VERTEX): comparing multi-electrode recordings from simulated and biological mammalian cortical tissue.

    Science.gov (United States)

    Tomsett, Richard J; Ainsworth, Matt; Thiele, Alexander; Sanayei, Mehdi; Chen, Xing; Gieselmann, Marc A; Whittington, Miles A; Cunningham, Mark O; Kaiser, Marcus

    2015-07-01

    Local field potentials (LFPs) sampled with extracellular electrodes are frequently used as a measure of population neuronal activity. However, relating such measurements to underlying neuronal behaviour and connectivity is non-trivial. To help study this link, we developed the Virtual Electrode Recording Tool for EXtracellular potentials (VERTEX). We first identified a reduced neuron model that retained the spatial and frequency filtering characteristics of extracellular potentials from neocortical neurons. We then developed VERTEX as an easy-to-use Matlab tool for simulating LFPs from large populations (>100,000 neurons). A VERTEX-based simulation successfully reproduced features of the LFPs from an in vitro multi-electrode array recording of macaque neocortical tissue. Our model, with virtual electrodes placed anywhere in 3D, allows direct comparisons with the in vitro recording setup. We envisage that VERTEX will stimulate experimentalists, clinicians, and computational neuroscientists to use models to understand the mechanisms underlying measured brain dynamics in health and disease.

  2. Adding insult to injury: neural sensitivity to social exclusion is associated with internalizing symptoms in chronically peer-victimized girls.

    Science.gov (United States)

    Rudolph, Karen D; Miernicki, Michelle E; Troop-Gordon, Wendy; Davis, Megan M; Telzer, Eva H

    2016-05-01

    Despite evidence documenting activation of the social pain network in response to social rejection and its link to temporary distress, far less is known regarding its role in pervasive emotional difficulties. Moreover, research has not considered the intersection between neural activation to experimentally induced social exclusion and naturally occurring social adversity. This study examined an integrated social pain model of internalizing symptoms, which posits that (i) neural sensitivity in the social pain network is associated with internalizing symptoms, (ii) this linkage is more robust in youth with than without a history of social adversity, and (iii) heightened avoidance motivation serves as one pathway linking neural sensitivity and internalizing symptoms. During a functional magnetic resonance imaging scan, 47 adolescent girls (M age = 15.46 years, SD = .35) with well-characterized histories of peer victimization were exposed to social exclusion. Whole-brain analyses revealed that activation to exclusion in the social pain network was associated with internalizing symptoms. As anticipated, this linkage was stronger in chronically victimized than non-victimized girls and was partially accounted for by avoidance motivation. This research indicates the importance of integrating neural, social and psychological systems of development in efforts to elucidate risk for internalizing symptoms among adolescent girls.

  3. Development and Characterization of a Diamond-Insulated Graphitic Multi Electrode Array Realized with Ion Beam Lithography

    Directory of Open Access Journals (Sweden)

    Federico Picollo

    2014-12-01

    Full Text Available The detection of quantal exocytic events from neurons and neuroendocrine cells is a challenging task in neuroscience. One of the most promising platforms for the development of a new generation of biosensors is diamond, due to its biocompatibility, transparency and chemical inertness. Moreover, the electrical properties of diamond can be turned from a perfect insulator into a conductive material (resistivity ~mΩ·cm by exploiting the metastable nature of this allotropic form of carbon. A 16‑channels MEA (Multi Electrode Array suitable for cell culture growing has been fabricated by means of ion implantation. A focused 1.2 MeV He+ beam was scanned on a IIa single-crystal diamond sample (4.5 × 4.5 × 0.5 mm3 to cause highly damaged sub-superficial structures that were defined with micrometric spatial resolution. After implantation, the sample was annealed. This process provides the conversion of the sub-superficial highly damaged regions to a graphitic phase embedded in a highly insulating diamond matrix. Thanks to a three-dimensional masking technique, the endpoints of the sub-superficial channels emerge in contact with the sample surface, therefore being available as sensing electrodes. Cyclic voltammetry and amperometry measurements of solutions with increasing concentrations of adrenaline were performed to characterize the biosensor sensitivity. The reported results demonstrate that this new type of biosensor is suitable for in vitro detection of catecholamine release.

  4. Use of multi-electrode array recordings in studies of network synaptic plasticity in both time and space

    Institute of Scientific and Technical Information of China (English)

    Ming-Gang Liu; Xue-Feng Chen; Ting He; Zhen Li; Jun Chen

    2012-01-01

    Simultaneous multisite recording using multi-electrode arrays (MEAs) in cultured and acutely-dissociated brain slices and other tissues is an emerging technique in the field of network electrophysiology.Over the past 40 years,great efforts have been made by both scientists and commercial concerns,to advance this technique.The MEA technique has been widely applied to many regions of the brain,retina,heart and smooth muscle in various studies at the network level.The present review starts from the development of MEA techniques and their uses in brain preparations,and then specifically concentrates on the use of MEA recordings in studies of synaptic plasticity at the network level in both the temporal and spatial domains.Because the MEA technique helps bridge the gap between single-cell recordings and behavioral assays,its wide application will undoubtedly shed light on the mechanisms underlying brain functions and dysfunctions at the network level that remained largely unknown due to the technical difficulties before it matured.

  5. Assessment of delivery parameters with the multi-electrode array for development of a DNA vaccine against Bacillus anthracis.

    Science.gov (United States)

    Donate, Amy; Heller, Richard

    2013-12-01

    Gene electrotransfer (GET) enhances delivery of DNA vaccines by increasing both gene expression and immune responses. Our lab has developed the multi-electrode array (MEA) for DNA delivery to skin. The MEA was used at constant pulse duration (150 ms) and frequency (6.67 Hz). In this study, delivery parameters including applied voltage (5-45 V), amount of plasmid (100-300 μg), and number of treatments (2-3) were evaluated for delivery of a DNA vaccine. Mice were intradermally injected with plasmid expressing Bacillus anthracis protective antigen with or without GET and αPA serum titers measured. Within this experiment no significant differences were noted in antibody levels from varying dose or treatment number. However, significant differences were measured from applied voltages of 25 and 35 V. These voltages generated antibody levels between 20,000 and 25,000. Serum from animals vaccinated with these conditions also resulted in toxin neutralization in 40-60% of animals. Visual damage was noted at MEA conditions of 40 V. No damage was noted either visually or histologically from conditions of 35 V or below. These results reflect the importance of establishing appropriate electrical parameters and the potential for the MEA in non-invasive DNA vaccination against B. anthracis.

  6. Development and characterization of a diamond-insulated graphitic multi electrode array realized with ion beam lithography

    CERN Document Server

    Picollo, F; Carbone, E; Croin, L; Enrico, E; Forneris, J; Gosso, S; Olivero, P; Pasquarelli, A; Carabelli, V

    2016-01-01

    The detection of quantal exocytic events from neurons and neuroendocrine cells is a challenging task in neuroscience. One of the most promising platforms for the development of a new generation of biosensors is diamond, due to its biocompatibility, transparency and chemical inertness. Moreover, the electrical properties of diamond can be turned from a perfect insulator into a conductive material (resistivity Ohm cm) by exploiting the metastable nature of this allotropic form of carbon. A 16 channels MEA (Multi Electrode Array) suitable for cell culture growing has been fabricated by means of ion implantation. A focused 1.2 MeV He+ beam was scanned on a IIa single-crystal diamond sample (4.5x4.5x0.5 mm3) to cause highly damaged sub-superficial structures that were defined with micrometric spatial resolution. After implantation, the sample was annealed. This process provides the conversion of the sub-superficial highly damaged regions to a graphitic phase embedded in a highly insulating diamond matrix. Thanks t...

  7. Design and validation of a multi-electrode bioimpedance system for enhancing spatial resolution of cellular impedance studies.

    Science.gov (United States)

    Alexander, Frank A; Celestin, Michael; Price, Dorielle T; Nanjundan, Meera; Bhansali, Shekhar

    2013-07-01

    This paper reports the design and evaluation of a multi-electrode design that improves upon the statistical significance and spatial resolution of cellular impedance data measured using commercial electric cell-substrate impedance sensing (ECIS) systems. By evaluating cellular impedance using eight independent sensing electrodes, position-dependent impedance measurements can be recorded across the device and compare commonly used equivalent circuit and mathematical models for extraction of cell parameters. Data from the 8-electrode device was compared to data taken from commercial electric cell-substrate impedance sensing (ECIS) system by deriving a relationship between equivalent circuit and mathematically modelled parameters. The impedance systems were evaluated and compared by investigating the effects of arsenic trioxide (As2O3), a well-established chemotherapeutic agent, on ovarian cancer cells. Impedance spectroscopy, a non-destructive, label-free technique, was used to continuously measure the frequency-dependent cellular properties, without adversely affecting the cells. The importance of multiple measurements within a cell culture was demonstrated; and the data illustrated that the non-uniform response of cells within a culture required redundant measurements in order to obtain statistically significant data, especially for drug discovery applications. Also, a correlation between equivalent circuit modelling and mathematically modelled parameters was derived, allowing data to be compared across different modelling techniques.

  8. Differential Neural Processing during Motor Imagery of Daily Activities in Chronic Low Back Pain Patients.

    Directory of Open Access Journals (Sweden)

    Andrea Vrana

    Full Text Available Chronic low back pain (chronic LBP is both debilitating for patients but also a major burden on the health care system. Previous studies reported various maladaptive structural and functional changes among chronic LBP patients on spine- and supraspinal levels including behavioral alterations. However, evidence for cortical reorganization in the sensorimotor system of chronic LBP patients is scarce. Motor Imagery (MI is suitable for investigating the cortical sensorimotor network as it serves as a proxy for motor execution. Our aim was to investigate differential MI-driven cortical processing in chronic LBP compared to healthy controls (HC by means of functional magnetic resonance imaging (fMRI. Twenty-nine subjects (15 chronic LBP patients, 14 HC were included in the current study. MI stimuli consisted of randomly presented video clips showing every-day activities involving different whole-body movements as well as walking on even ground and walking downstairs and upstairs. Guided by the video clips, subjects had to perform MI of these activities, subsequently rating the vividness of their MI performance. Brain activity analysis revealed that chronic LBP patients exhibited significantly reduced activity compared to HC subjects in MI-related brain regions, namely the left supplementary motor area and right superior temporal sulcus. Furthermore, psycho-physiological-interaction analysis yielded significantly enhanced functional connectivity (FC between various MI-associated brain regions in chronic LBP patients indicating diffuse and non-specific changes in FC. Current results demonstrate initial findings about differences in MI-driven cortical processing in chronic LBP pointing towards reorganization processes in the sensorimotor network.

  9. Neural Blockade in the Evaluation and Management of Chronic Pain: An Overview

    Directory of Open Access Journals (Sweden)

    Ian Gilron

    2000-01-01

    Full Text Available Local anesthetic and neurolytic nerve blocks have been used for over a century in the evaluation and management of chronic pain, despite a the dearth of evidence supporting their application. This article provides a general overview of the physiology and pharmacology of nerve blocks and suggests how they may affect pathophysiological mechanisms of chronic pain. Following a discussion of the rationale, clinical application and potential complications of nerve blocks, existing evidence of efficacy is reviewed. Further research evaluating mechanisms and efficacy of nerve blocks is vital to define their role in chronic pain management.

  10. Safety of atrial fibrillation ablation with novel multi-electrode array catheters on uninterrupted anticoagulation-a single-center experience.

    LENUS (Irish Health Repository)

    Hayes, Christopher Ruslan

    2012-02-01

    INTRODUCTION: A recent single-center report indicated that the performance of atrial fibrillation ablation in patients on uninterrupted warfarin using a conventional deflectable tip electrode ablation catheter may be as safe as periprocedural discontinuation of warfarin and bridging with heparin. Novel multi-electrode array catheters for atrial fibrillation ablation are currently undergoing clinical evaluation. While offering the possibility of more rapid atrial fibrillation ablation, they are stiffer and necessitate the deployment of larger deflectable transseptal sheaths, and it remains to be determined if they increase the risk of cardiac perforation and vascular injury. Such potential risks would have implications for a strategy of uninterrupted periprocedural anticoagulation. METHOD AND RESULTS: We audited the safety outcomes of our atrial fibrillation ablation procedures using multi-electrode array ablation catheters in patients on uninterrupted warfarin (CHADS2 score>or=2) and in patients not on warfarin (uninterrupted aspirin). Two bleeding complications occurred in 49 patients on uninterrupted warfarin, both of which were managed successfully without longterm sequelae, and no bleeding complication occurred in 32 patients not on warfarin (uninterrupted aspirin). There were no thromboembolic events or other complication with either anticoagulant regimen. CONCLUSION: Despite the larger diameter and increased stiffness of multi-electrode array catheters and their deflectable transseptal sheaths, their use for catheter ablation in patients with atrial fibrillation on uninterrupted warfarin in this single-center experience does not appear to be unsafe, and thus, an adequately powered multicenter prospective randomized controlled trial should be considered.

  11. LINGO-1-Fc-Transduced Neural Stem Cells Are Effective Therapy for Chronic Stage Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Li, Xing; Zhang, Yuan; Yan, Yaping; Ciric, Bogoljub; Ma, Cun-Gen; Chin, Jeannie; Curtis, Mark; Rostami, Abdolmohamad; Zhang, Guang-Xian

    2016-06-25

    The chronic stage multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS), remains refractory to current treatments. This refractory nature may be due to the fact that current treatments are primarily immunomodulatory, which prevent further demyelination but lack the capacity to promote remyelination. Several approaches, including transplantation of neural stem cells (NSCs) or antagonists to LINGO-1, a key part of the receptor complex for neuroregeneration inhibitors, have been effective in suppressing the acute stage of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, their effect on the chronic stage EAE is not known. Here, we show that transplantation of NSCs had only a slight therapeutic effect when treatment started at the chronic stage of EAE (e.g., injected at day 40 postimmunization). However, NSCs engineered to produce LINGO-1-Fc, a soluble LINGO-1 antagonist, significantly promoted neurological recovery as demonstrated by amelioration of clinical signs, improvement in axonal integrity, and enhancement of oligodendrocyte maturation and neuron repopulation. Significantly enhanced NAD production and Sirt2 expression were also found in the CNS of mice treated with LINGO-1-Fc-producing NSC. Moreover, differentiation of LINGO-1-Fc-producing NSCs into oligodendrocytes in vitro was largely diminished by an NAMPT inhibitor, indicating that LINGO-1-Fc enhances the NAMPT/NAD/Sirt2 pathway. Together, our study establishes a CNS-targeted, novel LINGO-1-Fc delivery system using NSCs, which represents a novel and effective NSC-based gene therapy approach for the chronic stage of MS.

  12. A neural model for chronic pain and pain relief by extracorporeal shock wave treatment.

    Science.gov (United States)

    Wess, Othmar J

    2008-12-01

    The paper develops a new theory of chronic pain and pain relief by extracorporeal shock wave treatment. Chronic pain without underlying anatomical disorder is looked at as a pathological control function of memory. Conditioned reflexes are considered to be engraved memory traces linking sensory input of afferent signals with motor response of efferent signals. This feature can be described by associative memory functions of the nervous system. Some conditioned reflexes may cause inappropriate or pathological reactions. Consequently, a circulus vitiosus of pain sensation and muscle and/or vessel contraction is generated when pain becomes chronic (pain spiral). The key feature is a dedicated engram responsible for a pathological (painful) reaction. The pain memory may be explained by the concept of a holographic memory model published by several authors. According to this model it is shown how nervous systems may generate and recall memory contents. The paper shows how extracorporeal shock wave treatment may reorganize pathologic memory traces, thus giving cause to real and permanent pain relief. In a generalized manner, the idea of associative memory functions may help in the understanding of conditioning as a learning process and explain extracorporeal shock wave application as an efficient treatment concept for chronic pain. This concept may open the door for new treatment approaches to chronic pain and several other disorders of the nervous system.

  13. Implanted neural electrodes cause chronic, local inflammation that is correlated with local neurodegeneration

    Science.gov (United States)

    McConnell, George C.; Rees, Howard D.; Levey, Allan I.; Gutekunst, Claire-Anne; Gross, Robert E.; Bellamkonda, Ravi V.

    2009-10-01

    Prosthetic devices that are controlled by intracortical electrodes recording one's 'thoughts' are a reality today, and no longer merely in the realm of science fiction. However, widespread clinical use of implanted electrodes is hampered by a lack of reliability in chronic recordings, independent of the type of electrodes used. One major hypothesis has been that astroglial scar electrically impedes the electrodes. However, there is a temporal discrepancy between stabilization of scar's electrical properties and recording failure with recording failure lagging by 1 month. In this study, we test a possible explanation for this discrepancy: the hypothesis that chronic inflammation, due to the persistent presence of the electrode, causes a local neurodegenerative state in the immediate vicinity of the electrode. Through modulation of chronic inflammation via stab wound, electrode geometry and age-matched control, we found that after 16 weeks, animals with an increased level of chronic inflammation were associated with increased neuronal and dendritic, but not axonal, loss. We observed increased neuronal and dendritic loss 16 weeks after implantation compared to 8 weeks after implantation, suggesting that the local neurodegenerative state is progressive. After 16 weeks, we observed axonal pathology in the form of hyperphosphorylation of the protein tau in the immediate vicinity of the microelectrodes (as observed in Alzheimer's disease and other tauopathies). The results of this study suggest that a local, late onset neurodegenerative disease-like state surrounds the chronic electrodes and is a potential cause for chronic recording failure. These results also inform strategies to enhance our capability to attain reliable long-term recordings from implantable electrodes in the CNS.

  14. Using a sensitivity study to facilitate the design of a multi-electrode array to measure six cardiac conductivity values.

    Science.gov (United States)

    Johnston, Barbara M

    2013-07-01

    When using the bidomain model to model the electrical activity of the heart, there are potentially six cardiac conductivity values involved: conductivity values in directions along and normal to the cardiac fibres with a sheet, as well as a conductivity value in the normal direction between the sheets, and these occur for both the extracellular and intracellular domains in the model. To date it has been common to assume that the two normal direction conductivity values are the same. However, recent work has demonstrated that six cardiac conductivity values, rather than four, are necessary for accurate modelling, which can then facilitate understanding of cardiovascular disease. To design a method to determine these conductivities, it is also necessary to design a suitable multi-electrode array, which can be used, in conjunction with an inversion technique, to retrieve conductivity values from measurements of potential made on the array. This work uses the results of a study, into the sensitivity of the measuring potentials to variability in the input conductivities, to facilitate the design of an array that could be used to retrieve six cardiac conductivity values, as well as fibre rotation angle. It is found that if an electrode in the array has a much lower value of potential than the other electrodes, then it tends to be much more sensitive to the input conductivities than the other electrodes. It also appears that inclusion of this type of electrode in the set of measuring electrodes is essential for accurately retrieving conductivity values. This technique is used to identify electrodes to be included in the array and using the final design it is demonstrated, using synthetic values of potential, that the six cardiac conductivity values, and the fibre rotation angle, can be retrieved very accurately.

  15. The effects of chronic intracortical microstimulation on neural tissue and fine motor behavior

    Science.gov (United States)

    Rajan, Alexander T.; Boback, Jessica L.; Dammann, John F.; Tenore, Francesco V.; Wester, Brock A.; Otto, Kevin J.; Gaunt, Robert A.; Bensmaia, Sliman J.

    2015-12-01

    Objective. One approach to conveying sensory feedback in neuroprostheses is to electrically stimulate sensory neurons in the cortex. For this approach to be viable, it is critical that intracortical microstimulation (ICMS) causes minimal damage to the brain. Here, we investigate the effects of chronic ICMS on the neuronal tissue across a variety of stimulation regimes in non-human primates. We also examine each animal’s ability to use their hand—the cortical representation of which is targeted by the ICMS—as a further assay of possible neuronal damage. Approach. We implanted electrode arrays in the primary somatosensory cortex of three Rhesus macaques and delivered ICMS four hours per day, five days per week, for six months. Multiple regimes of ICMS were delivered to investigate the effects of stimulation parameters on the tissue and behavior. Parameters included current amplitude (10-100 μA), pulse train duration (1, 5 s), and duty cycle (1/1, 1/3). We then performed a range of histopathological assays on tissue near the tips of both stimulated and unstimulated electrodes to assess the effects of chronic ICMS on the tissue and their dependence on stimulation parameters. Main results. While the implantation and residence of the arrays in the cortical tissue did cause significant damage, chronic ICMS had no detectable additional effect; furthermore, the animals exhibited no impairments in fine motor control. Significance. Chronic ICMS may be a viable means to convey sensory feedback in neuroprostheses as it does not cause significant damage to the stimulated tissue.

  16. Recombinant neural progenitor transplants in the spinal dorsal horn alleviate chronic central neuropathic pain.

    Science.gov (United States)

    Jergova, Stanislava; Gajavelli, Shyam; Pathak, Nirmal; Sagen, Jacqueline

    2016-04-01

    Neuropathic pain induced by spinal cord injury (SCI) is clinically challenging with inadequate long-term treatment options. Partial pain relief offered by pharmacologic treatment is often counterbalanced by adverse effects after prolonged use in chronic pain patients. Cell-based therapy for neuropathic pain using GABAergic neuronal progenitor cells (NPCs) has the potential to overcome untoward effects of systemic pharmacotherapy while enhancing analgesic potency due to local activation of GABAergic signaling in the spinal cord. However, multifactorial anomalies underlying chronic pain will likely require simultaneous targeting of multiple mechanisms. Here, we explore the analgesic potential of genetically modified rat embryonic GABAergic NPCs releasing a peptidergic NMDA receptor antagonist, Serine-histogranin (SHG), thus targeting both spinal hyperexcitability and reduced inhibitory processes. Recombinant NPCs were designed using either lentiviral or adeno-associated viral vectors (AAV2/8) encoding single and multimeric (6 copies of SHG) cDNA. Intraspinal injection of recombinant cells elicited enhanced analgesic effects compared with nonrecombinant NPCs in SCI-induced pain in rats. Moreover, potent and sustained antinociception was achieved, even after a 5-week postinjury delay, using recombinant multimeric NPCs. Intrathecal injection of SHG antibody attenuated analgesic effects of the recombinant grafts suggesting active participation of SHG in these antinociceptive effects. Immunoblots and immunocytochemical assays indicated ongoing recombinant peptide production and secretion in the grafted host spinal cords. These results support the potential for engineered NPCs grafted into the spinal dorsal horn to alleviate chronic neuropathic pain.

  17. Supernumerary Formation of Olfactory Glomeruli Induced by Chronic Odorant Exposure: A Constructivist Expression of Neural Plasticity

    Science.gov (United States)

    Valle-Leija, Pablo; Blanco-Hernández, Eduardo; Drucker-Colín, Rene; Gutiérrez-Ospina, Gabriel; Vidaltamayo, Roman

    2012-01-01

    It is accepted that sensory experience instructs the remodelling of neuronal circuits during postnatal development, after their specification has occurred. The story is less clear with regard to the role of experience during the initial formation of neuronal circuits, whether prenatal or postnatal, since this process is now supposed to be primarily influenced by genetic determinants and spontaneous neuronal firing. Here we evaluated this last issue by examining the effect that postnatal chronic exposure to cognate odorants has on the formation of I7 and M72 glomeruli, iterated olfactory circuits that are formed before and after birth, respectively. We took advantage of double knock-in mice whose I7 and M72 primary afferents express green fluorescent protein and β-galactosidase, correspondingly. Our results revealed that postnatal odorant chronic exposure led to the formation of permanent supernumerary I7 and M72 glomeruli in a dose and time dependent manner. Glomeruli in exposed mice were formed within the same regions of olfactory bulb and occupy small space volumes compared to the corresponding single circuits in non-exposed mice. We suggest that local reorganization of the primary afferents could participate in the process of formation of supernumerary glomeruli. Overall, our results support that sensory experience indeed instructs the permanent formation of specific glomeruli in the mouse olfactory bulb by means of constructivist processes. PMID:22511987

  18. Neural correlates of fear of movement in patients with chronic low back pain versus pain-free individuals

    Directory of Open Access Journals (Sweden)

    Michael Lukas Meier

    2016-07-01

    Full Text Available Fear of movement (FOM can be acquired by a direct aversive experience such as pain or by social learning through observation and instruction. Excessive FOM results in heightened disability and is an obstacle for recovery from acute, subacute, and chronic low back pain (cLBP. FOM has further been identified as a significant explanatory factor in the Fear Avoidance (FA model of cLBP that describes how individuals experiencing acute back pain may become trapped into a vicious circle of chronic disability and suffering. Despite a wealth of evidence emphasizing the importance of FOM in cLBP, to date, no related neural correlates in patients were found and this therefore has initiated a debate about the precise contribution of fear in the FA model. In the current fMRI study, we applied a novel approach encompassing 1 video clips of potentially harmful activities for the back as FOM inducing stimuli and 2 the assessment of FOM in both, cLBP patients (N = 20 and age- and gender-matched pain-free subjects (N = 20. Derived from the FA model, we hypothesized that FOM differentially affects brain regions involved in fear processing in patients with cLBP compared to pain-free individuals due to the recurrent pain and subsequent avoidance behaviour. The results of the whole brain voxel-wise regression analysis revealed that 1 FOM positively correlated with brain activity in fear-related brain regions such as the amygdala and the insula and 2 Differential effects of FOM between patients with cLBP and pain-free subjects were found in the extended amygdala and in its connectivity to the anterior insula. Current findings support the FOM component of the FA model in cLBP.

  19. Chronic multichannel neural recordings from soft regenerative microchannel electrodes during gait.

    Science.gov (United States)

    Musick, Katherine M; Rigosa, Jacopo; Narasimhan, Shreya; Wurth, Sophie; Capogrosso, Marco; Chew, Daniel J; Fawcett, James W; Micera, Silvestro; Lacour, Stéphanie P

    2015-09-24

    Reliably interfacing a nerve with an electrode array is one of the approaches to restore motor and sensory functions after an injury to the peripheral nerve. Accomplishing this with current technologies is challenging as the electrode-neuron interface often degrades over time, and surrounding myoelectric signals contaminate the neuro-signals in awake, moving animals. The purpose of this study was to evaluate the potential of microchannel electrode implants to monitor over time and in freely moving animals, neural activity from regenerating nerves. We designed and fabricated implants with silicone rubber and elastic thin-film metallization. Each implant carries an eight-by-twelve matrix of parallel microchannels (of 120 × 110 μm(2) cross-section and 4 mm length) and gold thin-film electrodes embedded in the floor of ten of the microchannels. After sterilization, the soft, multi-lumen electrode implant is sutured between the stumps of the sciatic nerve. Over a period of three months and in four rats, the microchannel electrodes recorded spike activity from the regenerating sciatic nerve. Histology indicates mini-nerves formed of axons and supporting cells regenerate robustly in the implants. Analysis of the recorded spikes and gait kinematics over the ten-week period suggests firing patterns collected with the microchannel electrode implant can be associated with different phases of gait.

  20. Chronic multichannel neural recordings from soft regenerative microchannel electrodes during gait

    Science.gov (United States)

    Musick, Katherine M.; Rigosa, Jacopo; Narasimhan, Shreya; Wurth, Sophie; Capogrosso, Marco; Chew, Daniel J.; Fawcett, James W.; Micera, Silvestro; Lacour, Stéphanie P.

    2015-09-01

    Reliably interfacing a nerve with an electrode array is one of the approaches to restore motor and sensory functions after an injury to the peripheral nerve. Accomplishing this with current technologies is challenging as the electrode-neuron interface often degrades over time, and surrounding myoelectric signals contaminate the neuro-signals in awake, moving animals. The purpose of this study was to evaluate the potential of microchannel electrode implants to monitor over time and in freely moving animals, neural activity from regenerating nerves. We designed and fabricated implants with silicone rubber and elastic thin-film metallization. Each implant carries an eight-by-twelve matrix of parallel microchannels (of 120 × 110 μm2 cross-section and 4 mm length) and gold thin-film electrodes embedded in the floor of ten of the microchannels. After sterilization, the soft, multi-lumen electrode implant is sutured between the stumps of the sciatic nerve. Over a period of three months and in four rats, the microchannel electrodes recorded spike activity from the regenerating sciatic nerve. Histology indicates mini-nerves formed of axons and supporting cells regenerate robustly in the implants. Analysis of the recorded spikes and gait kinematics over the ten-week period suggests firing patterns collected with the microchannel electrode implant can be associated with different phases of gait.

  1. Interactions between chronic ethanol consumption and thiamine deficiency on neural plasticity, spatial memory and cognitive flexibility

    Science.gov (United States)

    Vedder, Lindsey C.; Hall, Joseph M.; Jabrouin, Kimberly R.; Savage, Lisa M.

    2015-01-01

    Background Many alcoholics display moderate to severe cognitive dysfunction accompanied by brain pathology. A factor confounded with prolonged heavy alcohol consumption is poor nutrition and many alcoholics are thiamine deficient. Thus, thiamine deficiency (TD) has emerged as a key factor underlying alcohol–related brain damage (ARBD). TD in humans can lead to Wernicke Encephalitis that can progress into Wernicke–Korsakoff Syndrome and these disorders have a high prevalence among alcoholics. Animal models are critical for determining the exact contributions of ethanol- and TD-induced neurotoxicity, as well as the interactions of those factors to brain and cognitive dysfunction. Methods Adult rats were randomly assigned to one of six treatment conditions: Chronic ethanol treatment (CET) where rats consumed a 20% v/v solution of ethanol over 6 months; Severe pyrithiamine-induced TD (PTD-MAS); Moderate PTD (PTD-EAS); Moderate PTD followed by CET (PTD-CET); Moderate PTD during CET (CET-PTD); Pair-fed control (PF). After recovery from treatment, all rats were tested on spontaneous alternation and attentional set-shifting. After behavioral testing, brains were harvested for determination of mature brain-derived neurotrophic factor (BDNF) and thalamic pathology. Results Moderate TD combined with CET, regardless of treatment order, produced significant impairments in spatial memory, cognitive flexibility and reductions in brain plasticity as measured by BDNF levels in the frontal cortex and hippocampus. These alterations are greater than those seen in moderate TD alone and the synergistic effects of moderate TD with CET leads to a unique cognitive profile. However, CET did not exacerbate thalamic pathology seen after moderate TD. Conclusions These data support the emerging theory that subclinical TD during chronic heavy alcohol consumption is critical for the development of significant cognitive impairment associated with ARBD. PMID:26419807

  2. The measurement of gas-liquid two-phase flows in a small diameter pipe using a dual-sensor multi-electrode conductance probe

    Science.gov (United States)

    Zhai, Lu-Sheng; Bian, Peng; Han, Yun-Feng; Gao, Zhong-Ke; Jin, Ning-De

    2016-04-01

    We design a dual-sensor multi-electrode conductance probe to measure the flow parameters of gas-liquid two-phase flows in a vertical pipe with an inner diameter of 20 mm. The designed conductance probe consists of a phase volume fraction sensor (PVFS) and a cross-correlation velocity sensor (CCVS). Through inserting an insulated flow deflector in the central part of the pipe, the gas-liquid two-phase flows are forced to pass through an annual space. The multiple electrodes of the PVFS and the CCVS are flush-mounted on the inside of the pipe wall and the outside of the flow deflector, respectively. The geometry dimension of the PVFS is optimized based on the distribution characteristics of the sensor sensitivity field. In the flow loop test of vertical upward gas-liquid two-phase flows, the output signals from the dual-sensor multi-electrode conductance probe are collected by a data acquisition device from the National Instruments (NI) Corporation. The information transferring characteristics of local flow structures in the annular space are investigated using the transfer entropy theory. Additionally, the kinematic wave velocity is measured based on the drift velocity model to investigate the propagation behavior of the stable kinematic wave in the annular space. Finally, according to the motion characteristics of the gas-liquid two-phase flows, the drift velocity model based on the flow patterns is constructed to measure the individual phase flow rate with higher accuracy.

  3. Bumetanide promotes neural precursor cell regeneration and dendritic development in the hippocampal dentate gyrus in the chronic stage of cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Wang-shu Xu; Xuan Sun; Cheng-guang Song; Xiao-peng Mu; Wen-ping Ma; Xing-hu Zhang; Chuan-sheng Zhao

    2016-01-01

    Bumetanide has been shown to lessen cerebral edema and reduce the infarct area in the acute stage of cerebral ischemia. Few studies focus on the effects of bumetanide on neuroprotection and neurogenesis in the chronic stage of cerebral ischemia. We established a rat model of cerebral ischemia by injecting endothelin-1 in the left cortical motor area and left corpus striatum. Seven days later, bumeta-nide 200 µg/kg/day was injected into the lateral ventricle for 21 consecutive days with a mini-osmotic pump. Results demonstrated that the number of neuroblasts cells and the total length of dendrites increased, escape latency reduced, and the number of platform crossings increased in the rat hippocampal dentate gyrus in the chronic stage of cerebral ischemia. These ifndings suggest that bumetanide promoted neural precursor cell regeneration, dendritic development and the recovery of cognitive function, and protected brain tissue in the chronic stage of ischemia.

  4. Bursting dynamics of in vitro neural networks and their stimulation driven learning.

    Science.gov (United States)

    Choi, Joon Ho; Hoan Kim, June; Lee, Kyoung J.

    2009-03-01

    Recent studies have indicated that recurring neural ``bursts'' may play an essential role in neural information processing and memory. One key element of this hypothesis involves the translation of temporal patterns of stimuli into spatiotemporally distributed information. One ideal system to investigate this issue is cultured network of neurons grown on multi-electrode array (MEA). Based on such in vitro systems, we have investigated the changes incurred by extrinsic stimuli in the spontaneously recurring bursting activities. We have employed, in particular, two-channel paired, delayed, tetanic stimuli to evoke different patterns of bursting activities. Our preliminary data suggests that the neural network can exhibit some learning behavior.

  5. Use of 2D Multi Electrodes Resistivity Imagining for Sinkholes Hazard Assessment along the Eastern Part of the Dead Sea, Jordan

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    Abdallah S.   Al-Zoubi

    2007-01-01

    Full Text Available Sinkholes and subsidence are natural phenomena can be occurred in shallow geology sediments at different regions in the world. Sinkholes assessment is one of the most difficult near subsurface investigations. Geophysical prospecting is appropriate method to determine environmental and geotechnical problems. 2D multi electrodes resistivity imagining with Wenner-Schulmberge array was conducted within active sinkholes area. The objective of the survey is to detect features combined with sinkhole formation like zone of weakness, cavities and fractures. Soil in the study area contains alluvial, conglomerate and silty clay which represent good target for resistivity survey. The interpretation of resistivity data along the profiles show different model of the resistivity variation in active sinkhole zones compared with inactive zones in the study area. The deformation in the layer continuity and the direct contact between high resistive and low resistive layers can appear only in the subsidence area or active sinkhole zones.

  6. Resistance of subventricular neural stem cells to chronic hypoxemia despite structural disorganization of the germinal center and impairment of neuronal and oligodendrocyte survival

    Science.gov (United States)

    d’Anglemont de Tassigny, Xavier; Sirerol-Piquer, M Salomé; Gómez-Pinedo, Ulises; Pardal, Ricardo; Bonilla, Sonia; Capilla-Gonzalez, Vivian; López-López, Ivette; De la Torre-Laviana, Francisco Javier; García-Verdugo, José Manuel; López-Barneo, José

    2015-01-01

    Chronic hypoxemia, as evidenced in de-acclimatized high-altitude residents or in patients with chronic obstructive respiratory disorders, is a common medical condition that can produce serious neurological alterations. However, the pathogenesis of this phenomenon is unknown. We have found that adult rodents exposed for several days/weeks to hypoxia, with an arterial oxygen tension similar to that of chronically hypoxemic patients, manifest a partially irreversible structural disarrangement of the subventricular neurogenic niche (subventricular zone) characterized by displacement of neurons and myelinated axons, flattening of the ependymal cell layer, and thinning of capillary walls. Despite these abnormalities, the number of neuronal and oligodendrocyte progenitors, neuroblasts, and neurosphere-forming cells as well as the proliferative activity in subventricular zone was unchanged. These results suggest that neural stem cells and their undifferentiated progeny are resistant to hypoxia. However, in vivo and in vitro experiments indicate that severe chronic hypoxia decreases the survival of newly generated neurons and oligodendrocytes, with damage of myelin sheaths. These findings help explain the effects of hypoxia on adult neurogenesis and provide new perspectives on brain responsiveness to persistent hypoxemia. PMID:27774479

  7. Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

    Directory of Open Access Journals (Sweden)

    Nima eDehghani

    2012-08-01

    Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

  8. 多电极电磁流量计转换器设计%Design on converter of multi-electrode electromagnetic flow meter

    Institute of Scientific and Technical Information of China (English)

    赵宇洋; 张涛; LUCAS G

    2012-01-01

    A novel multi-electrode electromagnetic flow meter ( EMFM) based on weight value theory is developed which uses VM1 microcontroller as the processing core of the converter. The VM1 microcontroller is used to realize control magnetic circuit,acquire voltage signals,data reconstruction,display and regulating control and other functions. By measuring the induced voltages at the boundary of the flow field so as to reconstructs and real time display the velocity distribution. The experimental results demonstrate that this kind of electromagnetic flow meter has high measuring precision and provide reliable velocity reconstruction result.%基于权函数理论设计出一种新颖的多电极电磁流量计,其转换器部分采用VM1微处理器作为处理核心,实现控制磁路系统、信号采集、数据重构以及显示和调节控制等功能.该设计通过测量流场边界处的感应电压,进而重构速度分布并实时显示.实验证明:该种电磁流量计具有较高的测量精度,并提供可靠的速度重构结果.

  9. Multi-Electrode Resistivity Probe for Investigation of Local Temperature Inside Metal Shell Battery Cells via Resistivity: Experiments and Evaluation of Electrical Resistance Tomography

    Directory of Open Access Journals (Sweden)

    Xiaobin Hong

    2015-01-01

    Full Text Available Direct Current (DC electrical resistivity is a material property that is sensitive to temperature changes. In this paper, the relationship between resistivity and local temperature inside steel shell battery cells (two commercial 10 Ah and 4.5 Ah lithium-ion cells is innovatively studied by Electrical Resistance Tomography (ERT. The Schlumberger configuration in ERT is applied to divide the cell body into several blocks distributed in different levels, where the apparent resistivities are measured by multi-electrode surface probes. The investigated temperature ranges from −20 to 80 °C. Experimental results have shown that the resistivities mainly depend on temperature changes in each block of the two cells used and the function of the resistivity and temperature can be fitted to the ERT-measurement results in the logistical-plot. Subsequently, the dependence of resistivity on the state of charge (SOC is investigated, and the SOC range of 70%–100% has a remarkable impact on the resistivity at low temperatures. The proposed approach under a thermal cool down regime is demonstrated to monitor the local transient temperature.

  10. Spatio-temporal mapping of variation potentials in leaves of Helianthus annuus L. seedlings in situ using multi-electrode array.

    Science.gov (United States)

    Zhao, Dong-Jie; Wang, Zhong-Yi; Huang, Lan; Jia, Yong-Peng; Leng, John Q

    2014-06-25

    Damaging thermal stimuli trigger long-lasting variation potentials (VPs) in higher plants. Owing to limitations in conventional plant electrophysiological recording techniques, recorded signals are composed of signals originating from all of the cells that are connected to an electrode. This limitation does not enable detailed spatio-temporal distributions of transmission and electrical activities in plants to be visualised. Multi-electrode array (MEA) enables the recording and imaging of dynamic spatio-temporal electrical activities in higher plants. Here, we used an 8 × 8 MEA with a polar distance of 450 μm to measure electrical activities from numerous cells simultaneously. The mapping of the data that were recorded from the MEA revealed the transfer mode of the thermally induced VPs in the leaves of Helianthus annuus L. seedlings in situ. These results suggest that MEA can enable recordings with high spatio-temporal resolution that facilitate the determination of the bioelectrical response mode of higher plants under stress.

  11. Human neural stem cells differentiate and promote locomotor recovery in an early chronic spinal cord injury NOD-scid mouse model.

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    Desirée L Salazar

    Full Text Available BACKGROUND: Traumatic spinal cord injury (SCI results in partial or complete paralysis and is characterized by a loss of neurons and oligodendrocytes, axonal injury, and demyelination/dysmyelination of spared axons. Approximately 1,250,000 individuals have chronic SCI in the U.S.; therefore treatment in the chronic stages is highly clinically relevant. Human neural stem cells (hCNS-SCns were prospectively isolated based on fluorescence-activated cell sorting for a CD133(+ and CD24(-/lo population from fetal brain, grown as neurospheres, and lineage restricted to generate neurons, oligodendrocytes and astrocytes. hCNS-SCns have recently been transplanted sub-acutely following spinal cord injury and found to promote improved locomotor recovery. We tested the ability of hCNS-SCns transplanted 30 days post SCI to survive, differentiate, migrate, and promote improved locomotor recovery. METHODS AND FINDINGS: hCNS-SCns were transplanted into immunodeficient NOD-scid mice 30 days post spinal cord contusion injury. hCNS-SCns transplanted mice demonstrated significantly improved locomotor recovery compared to vehicle controls using open field locomotor testing and CatWalk gait analysis. Transplanted hCNS-SCns exhibited long-term engraftment, migration, limited proliferation, and differentiation predominantly to oligodendrocytes and neurons. Astrocytic differentiation was rare and mice did not exhibit mechanical allodynia. Furthermore, differentiated hCNS-SCns integrated with the host as demonstrated by co-localization of human cytoplasm with discrete staining for the paranodal marker contactin-associated protein. CONCLUSIONS: The results suggest that hCNS-SCns are capable of surviving, differentiating, and promoting improved locomotor recovery when transplanted into an early chronic injury microenvironment. These data suggest that hCNS-SCns transplantation has efficacy in an early chronic SCI setting and thus expands the "window of opportunity" for

  12. Data-driven model comparing the effects of glial scarring and interface interactions on chronic neural recordings in non-human primates

    Science.gov (United States)

    Malaga, Karlo A.; Schroeder, Karen E.; Patel, Paras R.; Irwin, Zachary T.; Thompson, David E.; Bentley, J. Nicole; Lempka, Scott F.; Chestek, Cynthia A.; Patil, Parag G.

    2016-02-01

    Objective. We characterized electrode stability over twelve weeks of impedance and neural recording data from four chronically-implanted Utah arrays in two rhesus macaques, and investigated the effects of glial scarring and interface interactions at the electrode recording site on signal quality using a computational model. Approach. A finite-element model of a Utah array microelectrode in neural tissue was coupled with a multi-compartmental model of a neuron to quantify the effects of encapsulation thickness, encapsulation resistivity, and interface resistivity on electrode impedance and waveform amplitude. The coupled model was then reconciled with the in vivo data. Histology was obtained seventeen weeks post-implantation to measure gliosis. Main results. From week 1-3, mean impedance and amplitude increased at rates of 115.8 kΩ/week and 23.1 μV/week, respectively. This initial ramp up in impedance and amplitude was observed across all arrays, and is consistent with biofouling (increasing interface resistivity) and edema clearing (increasing tissue resistivity), respectively, in the model. Beyond week 3, the trends leveled out. Histology showed that thin scars formed around the electrodes. In the model, scarring could not match the in vivo data. However, a thin interface layer at the electrode tip could. Despite having a large effect on impedance, interface resistivity did not have a noticeable effect on amplitude. Significance. This study suggests that scarring does not cause an electrical problem with regard to signal quality since it does not appear to be the main contributor to increasing impedance or significantly affect amplitude unless it displaces neurons. This, in turn, suggests that neural signals can be obtained reliably despite scarring as long as the recording site has sufficiently low impedance after accumulating a thin layer of biofouling. Therefore, advancements in microelectrode technology may be expedited by focusing on improvements to the

  13. Curcumin Alters Neural Plasticity and Viability of Intact Hippocampal Circuits and Attenuates Behavioral Despair and COX-2 Expression in Chronically Stressed Rats

    Science.gov (United States)

    Choi, Ga-Young; Kim, Hyun-Bum; Hwang, Eun-Sang; Lee, Seok; Kim, Min-Ji; Choi, Ji-Young; Lee, Sung-Ok

    2017-01-01

    Curcumin is a major diarylheptanoid component of Curcuma longa with traditional usage for anxiety and depression. It has been known for the anti-inflammatory, antistress, and neurotropic effects. Here we examined curcumin effect in neural plasticity and cell viability. 60-channel multielectrode array was applied on organotypic hippocampal slice cultures (OHSCs) to monitor the effect of 10 μM curcumin in long-term depression (LTD) through low-frequency stimulation (LFS) to the Schaffer collaterals and commissural pathways. Cell viability was assayed by propidium iodide uptake test in OHSCs. In addition, the influence of oral curcumin administration on rat behavior was assessed with the forced swim test (FST). Finally, protein expression levels of brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (COX-2) were measured by Western blot in chronically stressed rats. Our results demonstrated that 10 μM curcumin attenuated LTD and reduced cell death. It also recovered the behavior immobility of FST, rescued the attenuated BDNF expression, and inhibited the enhancement of COX-2 expression in stressed animals. These findings indicate that curcumin can enhance postsynaptic electrical reactivity and cell viability in intact neural circuits with antidepressant-like effects, possibly through the upregulation of BDNF and reduction of inflammatory factors in the brain. PMID:28167853

  14. Investigation of particle inertial migration in high particle concentration suspension flow by multi-electrodes sensing and Eulerian-Lagrangian simulation in a square microchannel.

    Science.gov (United States)

    Zhao, Tong; Yao, Jiafeng; Liu, Kai; Takei, Masahiro

    2016-03-01

    The inertial migration of neutrally buoyant spherical particles in high particle concentration (αpi  > 3%) suspension flow in a square microchannel was investigated by means of the multi-electrodes sensing method which broke through the limitation of conventional optical measurement techniques in the high particle concentration suspensions due to interference from the large particle numbers. Based on the measured particle concentrations near the wall and at the corner of the square microchannel, particle cross-sectional migration ratios are calculated to quantitatively estimate the migration degree. As a result, particle migration to four stable equilibrium positions near the centre of each face of the square microchannel is found only in the cases of low initial particle concentration up to 5.0 v/v%, while the migration phenomenon becomes partial as the initial particle concentration achieves 10.0 v/v% and disappears in the cases of the initial particle concentration αpi  ≥ 15%. In order to clarify the influential mechanism of particle-particle interaction on particle migration, an Eulerian-Lagrangian numerical model was proposed by employing the Lennard-Jones potential as the inter-particle potential, while the inertial lift coefficient is calculated by a pre-processed semi-analytical simulation. Moreover, based on the experimental and simulation results, a dimensionless number named migration index was proposed to evaluate the influence of the initial particle concentration on the particle migration phenomenon. The migration index less than 0.1 is found to denote obvious particle inertial migration, while a larger migration index denotes the absence of it. This index is helpful for estimation of the maximum initial particle concentration for the design of inertial microfluidic devices.

  15. The gastrointestinal electrical mapping suite (GEMS: software for analyzing and visualizing high-resolution (multi-electrode recordings in spatiotemporal detail

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    Yassi Rita

    2012-06-01

    Full Text Available Abstract Background Gastrointestinal contractions are controlled by an underlying bioelectrical activity. High-resolution spatiotemporal electrical mapping has become an important advance for investigating gastrointestinal electrical behaviors in health and motility disorders. However, research progress has been constrained by the low efficiency of the data analysis tasks. This work introduces a new efficient software package: GEMS (Gastrointestinal Electrical Mapping Suite, for analyzing and visualizing high-resolution multi-electrode gastrointestinal mapping data in spatiotemporal detail. Results GEMS incorporates a number of new and previously validated automated analytical and visualization methods into a coherent framework coupled to an intuitive and user-friendly graphical user interface. GEMS is implemented using MATLAB®, which combines sophisticated mathematical operations and GUI compatibility. Recorded slow wave data can be filtered via a range of inbuilt techniques, efficiently analyzed via automated event-detection and cycle clustering algorithms, and high quality isochronal activation maps, velocity field maps, amplitude maps, frequency (time interval maps and data animations can be rapidly generated. Normal and dysrhythmic activities can be analyzed, including initiation and conduction abnormalities. The software is distributed free to academics via a community user website and forum (http://sites.google.com/site/gimappingsuite. Conclusions This software allows for the rapid analysis and generation of critical results from gastrointestinal high-resolution electrical mapping data, including quantitative analysis and graphical outputs for qualitative analysis. The software is designed to be used by non-experts in data and signal processing, and is intended to be used by clinical researchers as well as physiologists and bioengineers. The use and distribution of this software package will greatly accelerate efforts to improve the

  16. Embryonic Stem Cell-Derived Neurons Grown on Multi-Electrode Arrays as a Novel In vitro Bioassay for the Detection of Clostridium botulinum Neurotoxins

    Science.gov (United States)

    Jenkinson, Stephen P.; Grandgirard, Denis; Heidemann, Martina; Tscherter, Anne; Avondet, Marc-André; Leib, Stephen L.

    2017-01-01

    Clostridium botulinum neurotoxins (BoNTs) are the most poisonous naturally occurring protein toxins known to mankind and are the causative agents of the severe and potentially life-threatening disease botulism. They are also known for their application as cosmetics and as unique bio-pharmaceuticals to treat an increasing number of neurological and non-neurological disorders. Currently, the potency of biologically active BoNT for therapeutic use is mainly monitored by the murine LD50-assay, an ethically disputable test causing suffering and death of a considerable number of mice. The aim of this study was to establish an in vitro assay as an alternative to the widely used in vivo mouse bioassay. We report a novel BoNT detection assay using mouse embryonic stem cell-derived neurons (mESN) cultured on multi-electrode arrays (MEAs). After 21 days in culture, the mESN formed a neuronal network showing spontaneous bursting activity based on functional synapses and express the necessary target proteins for BoNTs. Treating cultures for 6 h with 16.6 pM of BoNT serotype A and incubation with 1.66 pM BoNT/A or 33 Units/ml of Botox® for 24 h lead to a significant reduction of both spontaneous network bursts and average spike rate. This data suggests that mESN cultured on MEAs pose a novel, biologically relevant model that can be used to detect and quantify functional BoNT effects, thus accelerating BoNT research while decreasing animal use. PMID:28280466

  17. In vivo monitoring of glial scar proliferation on chronically implanted neural electrodes by fiber optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Yijing eXie

    2014-08-01

    Full Text Available In neural prosthetics and stereotactic neurosurgery, intracortical electrodes are often utilized for delivering therapeutic electrical pulses, and recording neural electrophysiological signals. Unfortunately, neuroinflammation impairs the neuron-electrode-interface by developing a compact glial encapsulation around the implants in long term. At present, analyzing this immune reaction is only feasible with post-mortem histology; currently no means for specific in vivo monitoring exist and most applicable imaging modalities can not provide information in deep brain regions. Optical coherence tomography (OCT is a well established imaging modality for in vivo studies, providing cellular resolution and up to 1.2 mm imaging depth in brain tissue. A fiber based spectral domain OCT was shown to be capable of minimally invasive brain imaging. In the present study, we propose to use a fiber based spectral domain OCT to monitor the progression of the tissue's immune response through scar encapsulation progress in a rat animal model. A fine fiber catheter was implanted in rat brain together with a flexible polyimide microelectrode in sight both of which used as a foreign body to induce the brain tissue immune reaction. OCT signals were collected from animals up to 12 weeks after implantation and thus gliotic scarring in vivo monitored for that time. Preliminary data showed a significant enhancement of the OCT backscattering signal during the first three weeks after implantation, and increased attenuation factor of the sampled tissue due to the glial scar formation.

  18. A highly compliant serpentine shaped polyimide interconnect for front-end strain relief in chronic neural implants.

    Science.gov (United States)

    Sankar, Viswanath; Sanchez, Justin C; McCumiskey, Edward; Brown, Nagid; Taylor, Curtis R; Ehlert, Gregory J; Sodano, Henry A; Nishida, Toshikazu

    2013-01-01

    While the signal quality of recording neural electrodes is observed to degrade over time, the degradation mechanisms are complex and less easily observable. Recording microelectrodes failures are attributed to different biological factors such as tissue encapsulation, immune response, and disruption of blood-brain barrier (BBB) and non-biological factors such as strain due to micromotion, insulation delamination, corrosion, and surface roughness on the recording site (1-4). Strain due to brain micromotion is considered to be one of the important abiotic factors contributing to the failure of the neural implants. To reduce the forces exerted by the electrode on the brain, a high compliance 2D serpentine shaped electrode cable was designed, simulated, and measured using polyimide as the substrate material. Serpentine electrode cables were fabricated using MEMS microfabrication techniques, and the prototypes were subjected to load tests to experimentally measure the compliance. The compliance of the serpentine cable was numerically modeled and quantitatively measured to be up to 10 times higher than the compliance of a straight cable of same dimensions and material.

  19. A highly compliant serpentine shaped polyimide interconnect for front-end strain relief in chronic neural implants

    Directory of Open Access Journals (Sweden)

    Viswanath eSankar

    2013-09-01

    Full Text Available While the signal quality of recording neural electrodes is observed to degrade over time, the degradation mechanisms are complex and less easily observable. Recording microelectrodes failures are attributed to different biological factors such as tissue encapsulation, immune response, and disruption of blood-brain barrier (BBB and non-biological factors such as strain due to micromotion, insulation delamination, corrosion, and surface roughness on the recording site (Polikov et. al., 2005; Prasad et. al., 2011; Streit et. al., 2012; Prasad et. al., 2012. Strain due to brain micromotion is considered to be one of the important abiotic factors contributing to the failure of the neural implants. To reduce the forces exerted by the electrode on the brain, a high compliance 2D serpentine shaped electrode cable was designed, simulated, and measured using polyimide as the substrate material. Serpentine electrode cables were fabricated using MEMS microfabrication techniques, and the prototypes were subjected to load tests to experimentally measure the compliance. The compliance of the serpentine cable was numerically modeled and quantitatively measured to be up to 10 times higher than the compliance of a straight cable of same dimensions and material.

  20. Transdiaphragmatic pressure and neural respiratory drive measured during inspiratory muscle training in stable patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Wu W

    2017-03-01

    Full Text Available Weiliang Wu,1 Xianming Zhang,2 Lin Lin,1 Yonger Ou,1 Xiaoying Li,1 Lili Guan,1 Bingpeng Guo,1 Luqian Zhou,1 Rongchang Chen1 1State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 2Department of Respiratory Medicine, The First Affiliated Hospital of Guizhou Medical University, Guizhou, People’s Republic of China Purpose: Inspiratory muscle training (IMT is a rehabilitation therapy for stable patients with COPD. However, its therapeutic effect remains undefined due to the unclear nature of diaphragmatic mobilization during IMT. Diaphragmatic mobilization, represented by transdiaphragmatic pressure (Pdi, and neural respiratory drive, expressed as the corrected root mean square (RMS of the diaphragmatic electromyogram (EMGdi, both provide vital information to select the proper IMT device and loads in COPD, therefore contributing to the curative effect of IMT. Pdi and RMS of EMGdi (RMSdi% were measured and compared during inspiratory resistive training and threshold load training in stable patients with COPD.Patients and methods: Pdi and neural respiratory drive were measured continuously during inspiratory resistive training and threshold load training in 12 stable patients with COPD (forced expiratory volume in 1 s ± SD was 26.1%±10.2% predicted.Results: Pdi was significantly higher during high-intensity threshold load training (91.46±17.24 cmH2O than during inspiratory resistive training (27.24±6.13 cmH2O in stable patients with COPD, with P<0.01 for each. Significant difference was also found in RMSdi% between high-intensity threshold load training and inspiratory resistive training (69.98%±16.78% vs 17.26%±14.65%, P<0.01.Conclusion: We concluded that threshold load training shows greater mobilization of Pdi and neural respiratory drive than inspiratory resistive training in stable patients with COPD. Keywords: diaphragmatic

  1. Effects of chronic furosemide on central neural hyperactivity and cochlear thresholds after cochlear trauma in guinea pig

    Directory of Open Access Journals (Sweden)

    Wilhelmina eMulders

    2014-08-01

    Full Text Available Increased neuronal spontaneous firing rates have been observed throughout the central auditory system after trauma to the cochlea and this hyperactivity is believed to be associated with the phantom perception of tinnitus. Previously we have shown in an animal model of hearing loss, that an acute injection with furosemide can significantly decrease hyperactivity after cochlear trauma and eliminate behavioural evidence of tinnitus of early onset. However, furosemide also has the potential to affect cochlear thresholds. In this paper we measured the effects of a chronic (daily injections for 7 days furosemide treatment on the spontaneous firing rate of inferior colliculus neurons and on cochlear thresholds in order to establish whether a beneficial effect on hyperactivity can be obtained without causing additional hearing loss. Guinea pigs were exposed to a 10 kHz, 124dB, 2 hour acoustic trauma, and after 5 days of recovery, were given daily i.p. injections of 80mg/kg furosemide or an equivalent amount of saline. The activity of single IC neurons was recorded 24 hours following the last injection. The furosemide treatment had no effect on cochlear thresholds compared to saline injections but did result in significant reductions in spontaneous firing rates recorded in inferior colliculus. These results that suggest a long term beneficial effect of furosemide on hyperactivity after cochlear trauma may be achievable without detrimental effects on hearing, which is important when considering therapeutic potential.

  2. Development of a multi-electrode extrapolation chamber as a prototype of a primary standard for the realization of the unit of the absorbed dose to water for beta brachytherapy sources

    CERN Document Server

    Bambynek, M

    2002-01-01

    The prototype of a primary standard has been developed, built and tested, which enables the realization of the unit of the absorbed dose to water for beta brachytherapy sources. In the course of the development of the prototype, the recommendations of the American Association of Physicists in Medicine (AAPM) Task Group 60 (TG60) and the Deutsche Gesellschaft fuer Medizinische Physik (DGMP) Arbeitskreis 18 (AK18) were taken into account. The prototype is based on a new multi-electrode extrapolation chamber (MEC) which meets, in particular, the requirements on high spatial resolution and small uncertainty. The central part of the MEC is a segmented collecting electrode which was manufactured in the clean room center of PTB by means of electron beam lithography on a wafer. A precise displacement device consisting of three piezoelectric macrotranslators has been incorporated to move the wafer collecting electrode against the entrance window. For adjustment of the wafer collecting electrode parallel to the entranc...

  3. A wireless transmission neural interface system for unconstrained non-human primates

    Science.gov (United States)

    Fernandez-Leon, Jose A.; Parajuli, Arun; Franklin, Robert; Sorenson, Michael; Felleman, Daniel J.; Hansen, Bryan J.; Hu, Ming; Dragoi, Valentin

    2015-10-01

    Objective. Studying the brain in large animal models in a restrained laboratory rig severely limits our capacity to examine brain circuits in experimental and clinical applications. Approach. To overcome these limitations, we developed a high-fidelity 96-channel wireless system to record extracellular spikes and local field potentials from the neocortex. A removable, external case of the wireless device is attached to a titanium pedestal placed in the animal skull. Broadband neural signals are amplified, multiplexed, and continuously transmitted as TCP/IP data at a sustained rate of 24 Mbps. A Xilinx Spartan 6 FPGA assembles the digital signals into serial data frames for transmission at 20 kHz though an 802.11n wireless data link on a frequency-shift key-modulated signal at 5.7-5.8 GHz to a receiver up to 10 m away. The system is powered by two CR123A, 3 V batteries for 2 h of operation. Main results. We implanted a multi-electrode array in visual area V4 of one anesthetized monkey (Macaca fascicularis) and in the dorsolateral prefrontal cortex (dlPFC) of a freely moving monkey (Macaca mulatta). The implanted recording arrays were electrically stable and delivered broadband neural data over a year of testing. For the first time, we compared dlPFC neuronal responses to the same set of stimuli (food reward) in restrained and freely moving conditions. Although we did not find differences in neuronal responses as a function of reward type in the restrained and unrestrained conditions, there were significant differences in correlated activity. This demonstrates that measuring neural responses in freely moving animals can capture phenomena that are absent in the traditional head-fixed paradigm. Significance. We implemented a wireless neural interface for multi-electrode recordings in freely moving non-human primates, which can potentially move systems neuroscience to a new direction by allowing one to record neural signals while animals interact with their environment.

  4. Neural substrate expansion for the restoration of brain function

    Directory of Open Access Journals (Sweden)

    Han-Chiao Isaac Chen

    2016-01-01

    Full Text Available Restoring neurological and cognitive function in individuals who have suffered brain damage is one of the principal objectives of modern translational neuroscience. Electrical stimulation approaches, such as deep-brain stimulation, have achieved the most clinical success, but they ultimately may be limited by the computational capacity of the residual cerebral circuitry. An alternative strategy is brain substrate expansion, in which the computational capacity of the brain is augmented through the addition of new processing units and the reconstitution of network connectivity. This latter approach has been explored to some degree using both biological and electronic means but thus far has not demonstrated the ability to reestablish the function of large-scale neuronal networks. In this review, we contend that fulfilling the potential of brain substrate expansion will require a significant shift from current methods that emphasize direct manipulations of the brain (e.g., injections of cellular suspensions and the implantation of multi-electrode arrays to the generation of more sophisticated neural tissues and neural-electric hybrids in vitro that are subsequently transplanted into the brain. Drawing from neural tissue engineering, stem cell biology, and neural interface technologies, this strategy makes greater use of the manifold techniques available in the laboratory to create biocompatible constructs that recapitulate brain architecture and thus are more easily recognized and utilized by brain networks.

  5. Chronic pancreatitis

    Science.gov (United States)

    Chronic pancreatitis - chronic; Pancreatitis - chronic - discharge; Pancreatic insufficiency - chronic; Acute pancreatitis - chronic ... alcohol abuse over many years. Repeated episodes of acute ... chronic pancreatitis. Genetics may be a factor in some cases. ...

  6. Integration of silicon-based neural probes and micro-drive arrays for chronic recording of large populations of neurons in behaving animals

    Science.gov (United States)

    Michon, Frédéric; Aarts, Arno; Holzhammer, Tobias; Ruther, Patrick; Borghs, Gustaaf; McNaughton, Bruce; Kloosterman, Fabian

    2016-08-01

    Objective. Understanding how neuronal assemblies underlie cognitive function is a fundamental question in system neuroscience. It poses the technical challenge to monitor the activity of populations of neurons, potentially widely separated, in relation to behaviour. In this paper, we present a new system which aims at simultaneously recording from a large population of neurons from multiple separated brain regions in freely behaving animals. Approach. The concept of the new device is to combine the benefits of two existing electrophysiological techniques, i.e. the flexibility and modularity of micro-drive arrays and the high sampling ability of electrode-dense silicon probes. Main results. Newly engineered long bendable silicon probes were integrated into a micro-drive array. The resulting device can carry up to 16 independently movable silicon probes, each carrying 16 recording sites. Populations of neurons were recorded simultaneously in multiple cortical and/or hippocampal sites in two freely behaving implanted rats. Significance. Current approaches to monitor neuronal activity either allow to flexibly record from multiple widely separated brain regions (micro-drive arrays) but with a limited sampling density or to provide denser sampling at the expense of a flexible placement in multiple brain regions (neural probes). By combining these two approaches and their benefits, we present an alternative solution for flexible and simultaneous recordings from widely distributed populations of neurons in freely behaving rats.

  7. 利用高密度电阻率法确定滑坡面的正演研究%Forward Modeling of Different Types of Landslides with Multi-electrode Electric Method

    Institute of Scientific and Technical Information of China (English)

    郭秀军; 黄潇雨; 贾永刚

    2005-01-01

    Multi-electrode Electric Method (MEM) is an effective tool in landslide survey. A suitable working scheme in-situ and the corresponding data interpretation approach are the fundamentals for obtaining believable results. Finite element 2D forward modeling was conducted on four types of standard electric models; respectively named the homogeneous soil landside, bedding landside, sliderock landside, and beveling landside; under the utilizations of four different types of electrode arrays;respectively namely the Wenner array, Schlumberger array, dipole-dipole array and pole-pole array.The capacities of different arrays and the resistivity responses of different types of sliding faces were determined based on the resultant standard electric profiles. An innovative data processing procedure called the ratio parameter method was proposed for locating sliding faces under complex geological conditions. A series of case histories for landside survey were given.%高密度电法探测是滑坡面探测的有效手段,适宜的现场工作方案和相应的资料解译模型,是获取可靠探测成果的前提.本文针对高密度电法勘探中常用的四类电极排列方式,即维纳、施伦贝谢、偶极、二极,利用有限元的方法二维正演模拟建立了均质土坡滑面、软弱夹层滑面、堆积层滑面、构造破碎带滑面的标准地电模型剖面;明确了进行不同类型滑坡工程地质调查时不同电测装置的探测能力和视电阻率异常模式;提出复杂地质条件下斜坡问题探测数据有效处理的设计比值参数方法.最后给出若干利用高密度电阻率法进行滑坡工程地质调查的典型实例.

  8. Transplantation of Neural Stem Cells Cotreated with Thyroid Hormone and GDNF Gene Induces Neuroprotection in Rats of Chronic Experimental Allergic Encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Xiaoqing Gao

    2016-01-01

    Full Text Available The present study investigates whether transplantation of NSCs treated with T3 alone (T3/NSCs, or in conjunction with GDNF gene (GDNF-T3/NSCs, provides a better therapeutic effect than NSCs for chronic EAE. EAE rats were, respectively, injected with NSCs, T3/NSCs, GDNF-T3/NSCs, and saline at 10 days and sacrificed at 60 days after EAE immunization. The three cell grafted groups showed a significant reduction in clinical scores, inflammatory infiltration, and demyelination compared with the saline-injected group, and among the cell grafted groups, the reduction in GDNF-T3/NSCs group was the most notable, followed by T3/NSCs group. Grafted T3/NSCs and GDNF-T3/NSCs acquired more MAP2, GalC, and less GFAP in brain compared with grafted NSCs, and grafted GDNF-T3/NSCs acquired most MAP2 and least GalC among the cell grafted groups. Furthermore, T3/NSCs and GDNF-T3/NSCs grafting increased the expression of mRNA for PDGFαR, GalC, and MBP in lesion areas of brain compared with NSCs grafting, and the expression of mRNA for GalC and MBP in GDNF-T3/NSCs group was higher than that in T3/NSCs group. In conclusion, T3/NSCs grafting, especially GDNF-T3/NSCs grafting, provides a better neuroprotective effect for EAE than NSCs transplantation.

  9. Chronic neural probe for simultaneous recording of single-unit, multi-unit, and local field potential activity from multiple brain sites

    Science.gov (United States)

    Pothof, F.; Bonini, L.; Lanzilotto, M.; Livi, A.; Fogassi, L.; Orban, G. A.; Paul, O.; Ruther, P.

    2016-08-01

    Objective. Drug resistant focal epilepsy can be treated by resecting the epileptic focus requiring a precise focus localisation using stereoelectroencephalography (SEEG) probes. As commercial SEEG probes offer only a limited spatial resolution, probes of higher channel count and design freedom enabling the incorporation of macro and microelectrodes would help increasing spatial resolution and thus open new perspectives for investigating mechanisms underlying focal epilepsy and its treatment. This work describes a new fabrication process for SEEG probes with materials and dimensions similar to clinical probes enabling recording single neuron activity at high spatial resolution. Approach. Polyimide is used as a biocompatible flexible substrate into which platinum electrodes and leads are integrated with a minimal feature size of 5 μm. The polyimide foils are rolled into the cylindrical probe shape at a diameter of 0.8 mm. The resulting probe features match those of clinically approved devices. Tests in saline solution confirmed the probe stability and functionality. Probes were implanted into the brain of one monkey (Macaca mulatta), trained to perform different motor tasks. Suitable configurations including up to 128 electrode sites allow the recording of task-related neuronal signals. Main results. Probes with 32 and 64 electrode sites were implanted in the posterior parietal cortex. Local field potentials and multi-unit activity were recorded as early as one hour after implantation. Stable single-unit activity was achieved for up to 26 days after implantation of a 64-channel probe. All recorded signals showed modulation during task execution. Significance. With the novel probes it is possible to record stable biologically relevant data over a time span exceeding the usual time needed for epileptic focus localisation in human patients. This is the first time that single units are recorded along cylindrical polyimide probes chronically implanted 22 mm deep into the

  10. A Functional Magnetic Resonance Imaging Study to Investigate the Utility of a Picture Imagination Task in Investigating Neural Responses in Patients with Chronic Musculoskeletal Pain to Daily Physical Activity Photographs.

    Directory of Open Access Journals (Sweden)

    Ann M Taylor

    Full Text Available Pain-related anxiety and fear are associated with increased difficulties in attention, increased awareness of pain, impaired disengagement from pain, and can moderate the effects of attentional coping attempts. Accurately assessing the direct impact of pain-related anxiety and fear on pain behavior has proved difficult. Studies have demonstrated no or limited influence of pain-related fear and anxiety on behavior but this may be due to inherent problems with the scales used. Neuroimaging has improved the understanding of neural processes underlying the factors that influence pain perception. This study aimed to establish if a Picture and Imagination Task (PIT, largely developed from the Photographs of Daily Activity (PHODA assessment tool, could help explore how people living with chronic pain process information about daily activities. Blood oxygenation level dependent (BOLD functional magnetic resonance imaging (fMRI was used to compare brain responses in patients with chronic musculoskeletal pain (CMSKP (n = 15 and healthy controls (n = 15. Subjects were asked to imagine how they would feel mentally and physically if asked to perform daily activities illustrated in PIT. The results found that a number of regions involved in pain processing saw increased BOLD activation in patients compared with controls when undertaking the task and included the insula, anterior cingulate cortex, thalamus and inferior and superior parietal cortices. Similarly, increased BOLD responses in patients compared to controls in the frontal pole, paracingulate and the supplementary motor cortex may be suggestive of a memory component to the responses The amygdala, orbitofrontal cortex, substantia nigra/ventral tegmentum, putamen, thalamus, pallidum, inferior parietal (supramarginal and angular gyrus and cingulate cortex were also seen to have greater differences in BOLD signal changes in patients compared with controls and many of these regions are also associated

  11. 慢性压迫性脊髓损伤后神经前体细胞的增殖%Proliferation of neural progenitor cell after chronic compressive injury of spinal cord

    Institute of Scientific and Technical Information of China (English)

    张绍文; 王栓科; 王翠芳; 夏亚一; 张海鸿; 汪玉良; 孙正义

    2006-01-01

    背景:关于成年哺乳类动物脊髓损伤后神经前体细胞的增殖特征和来源以及星形胶质细胞在其中的作用尚无肯定性结论.目的:通过分析成年大鼠慢性压迫性脊髓损伤及减压后巢蛋白和胶质纤维酸性蛋白表达的变化,探讨神经前体细胞的增殖特征和来源以及星形胶质细胞在其中的作用.设计:完全随机对照实验.单位:兰州大学第二医院骨科研究所.材料:实验于2003-03/10在兰州大学第二医院骨科研究所完成,选择成年健康Wistar大鼠50只.随机分为正常对照组、慢性压迫性脊髓损伤中度组(压迫物占椎管矢状径的40%)、重度组(压迫物占椎管矢状径的60%)及重度压迫损伤24 h后减压3 d、10 d组,每组10只.主要观察指标:①各组大鼠压迫临近段(距压迫边缘至5 mm)脊髓灰质和白质内nestin的阳性表达并测量其灰度值.②各组大鼠脊髓内胶质纤维酸性蛋白的表达.结果:50只大鼠均进入实验分析.①中度压迫组(白质235.33±6.48,灰质196.28±6.55)、重度压迫组(白质190.45±4.91,灰质173.15±5.98)及重度压迫损伤减压后3 d组(白质198.39±3.24,灰质180.38±4.51)和减压后10 d组白质(202.55±3.54)中巢蛋白均有明显表达(P<0.05),以重度压迫组最为显著(P<0.01).减压10 d组的灰质和脊髓中央管室管膜细胞的巢蛋白表达与正常对照组相比,差异无显著性意义(P>0.05).②与正常对照组相比,各损伤组脊髓内胶质纤维酸性蛋白表达增强,胶质纤维酸性蛋白阳性细胞数目增多、胞体肥大,突起增粗、增长.结论:成年大鼠慢性压迫性脊髓损伤及减压后早期存在神经前体细胞的增殖.星形胶质细胞参与神经前体细胞的增殖与迁移,对脊髓具有重要的营养修复作用.%BACKGROUND: There is still no affirmative conclusion on the proliferative characteristics and the sources of neural progenitor cells after chronic compressive injury of spinal

  12. Neural Networks

    Directory of Open Access Journals (Sweden)

    Schwindling Jerome

    2010-04-01

    Full Text Available This course presents an overview of the concepts of the neural networks and their aplication in the framework of High energy physics analyses. After a brief introduction on the concept of neural networks, the concept is explained in the frame of neuro-biology, introducing the concept of multi-layer perceptron, learning and their use as data classifer. The concept is then presented in a second part using in more details the mathematical approach focussing on typical use cases faced in particle physics. Finally, the last part presents the best way to use such statistical tools in view of event classifers, putting the emphasis on the setup of the multi-layer perceptron. The full article (15 p. corresponding to this lecture is written in french and is provided in the proceedings of the book SOS 2008.

  13. FGF Signaling Transforms Non-neural Ectoderm into Neural Crest

    OpenAIRE

    Yardley, Nathan; García-Castro, Martín I.

    2012-01-01

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in respons...

  14. Neural Network Applications

    NARCIS (Netherlands)

    Vonk, E.; Jain, L.C.; Veelenturf, L.P.J.

    1995-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  15. Chronic myelogenous leukemia (CML)

    Science.gov (United States)

    CML; Chronic myeloid leukemia; Chronic granulocytic leukemia; Leukemia - chronic granulocytic ... Chronic myelogenous leukemia is grouped into phases: Chronic Accelerated Blast crisis The chronic phase can last for ...

  16. Pharmacogenetics of neural injury recovery.

    Science.gov (United States)

    Pearson-Fuhrhop, Kristin M; Cramer, Steven C

    2013-10-01

    Relatively few pharmacological agents are part of routine care for neural injury, although several are used or under consideration in acute stroke, chronic stroke, traumatic brain injury and secondary stroke prevention. Tissue plasminogen activator is approved for the treatment of acute ischemic stroke, and genetic variants may impact the efficacy and safety of this drug. In the chronic phase of stroke, several drugs such as L-dopa, fluoxetine and donepezil are under investigation for enhancing rehabilitation therapy, with varying levels of evidence. One potential reason for the mixed efficacy displayed by these drugs may be the influence of genetic factors that were not considered in prior studies. An understanding of the genetics impacting the efficacy of dopaminergic, serotonergic and cholinergic drugs may allow clinicians to target these potential therapies to those patients most likely to benefit. In the setting of stroke prevention, which is directly linked to neural injury recovery, the most highly studied pharmacogenomic interactions pertain to clopidogrel and warfarin. Incorporating pharmacogenomics into neural injury recovery has the potential to maximize the benefit of several current and potential pharmacological therapies and to refine the choice of pharmacological agent that may be used to enhance benefits from rehabilitation therapy.

  17. Neural repair in the adult brain [version 1; referees: 3 approved

    OpenAIRE

    Sebastian Jessberger

    2016-01-01

    Acute or chronic injury to the adult brain often results in substantial loss of neural tissue and subsequent permanent functional impairment. Over the last two decades, a number of approaches have been developed to harness the regenerative potential of neural stem cells and the existing fate plasticity of neural cells in the nervous system to prevent tissue loss or to enhance structural and functional regeneration upon injury. Here, we review recent advances of stem cell-associated neural rep...

  18. Neural stimulation and recording electrodes.

    Science.gov (United States)

    Cogan, Stuart F

    2008-01-01

    Electrical stimulation of nerve tissue and recording of neural electrical activity are the basis of emerging prostheses and treatments for spinal cord injury, stroke, sensory deficits, and neurological disorders. An understanding of the electrochemical mechanisms underlying the behavior of neural stimulation and recording electrodes is important for the development of chronically implanted devices, particularly those employing large numbers of microelectrodes. For stimulation, materials that support charge injection by capacitive and faradaic mechanisms are available. These include titanium nitride, platinum, and iridium oxide, each with certain advantages and limitations. The use of charge-balanced waveforms and maximum electrochemical potential excursions as criteria for reversible charge injection with these electrode materials are described and critiqued. Techniques for characterizing electrochemical properties relevant to stimulation and recording are described with examples of differences in the in vitro and in vivo response of electrodes.

  19. Neural Induction, Neural Fate Stabilization, and Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Sally A. Moody

    2002-01-01

    Full Text Available The promise of stem cell therapy is expected to greatly benefit the treatment of neurodegenerative diseases. An underlying biological reason for the progressive functional losses associated with these diseases is the extremely low natural rate of self-repair in the nervous system. Although the mature CNS harbors a limited number of self-renewing stem cells, these make a significant contribution to only a few areas of brain. Therefore, it is particularly important to understand how to manipulate embryonic stem cells and adult neural stem cells so their descendants can repopulate and functionally repair damaged brain regions. A large knowledge base has been gathered about the normal processes of neural development. The time has come for this information to be applied to the problems of obtaining sufficient, neurally committed stem cells for clinical use. In this article we review the process of neural induction, by which the embryonic ectodermal cells are directed to form the neural plate, and the process of neural�fate stabilization, by which neural plate cells expand in number and consolidate their neural fate. We will present the current knowledge of the transcription factors and signaling molecules that are known to be involved in these processes. We will discuss how these factors may be relevant to manipulating embryonic stem cells to express a neural fate and to produce large numbers of neurally committed, yet undifferentiated, stem cells for transplantation therapies.

  20. Chronic stress in adulthood followed by intermittent stress impairs spatial memory and the survival of newborn hippocampal cells in aging animals: prevention by FGL, a peptide mimetic of neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Borcel, Erika; Pérez-Alvarez, Laura; Herrero, Ana Isabel;

    2008-01-01

    the decrease in the total number of granular neurons that resulted from prolonged exposure to stress. These findings suggest that the development of new drugs that mimic neural cell adhesion molecule activity might be of therapeutic relevance to treat stress-induced cognitive impairment....

  1. Chronic cholecystitis

    Science.gov (United States)

    Cholecystitis - chronic ... Most of the time, chronic cholecystitis is caused by repeated attacks of acute (sudden) cholecystitis. Most of these attacks are caused by gallstones in the gallbladder. These ...

  2. Chronic Pain

    Science.gov (United States)

    ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. × ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. ...

  3. Chronic Pain

    Science.gov (United States)

    ... a problem you need to take care of. Chronic pain is different. The pain signals go on ... there is no clear cause. Problems that cause chronic pain include Headache Low back strain Cancer Arthritis ...

  4. Chronic prostatitis

    OpenAIRE

    Le, Brian; Schaeffer, Anthony J.

    2011-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome [CP/CPPS]). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  5. Chronic prostatitis

    OpenAIRE

    Erickson, Bradley A.; Schaeffer, Anthony J.; Le, Brian

    2008-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome, CP/CPPS). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  6. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories.

    Directory of Open Access Journals (Sweden)

    Iris I A Groen

    Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.

  7. Neural mechanisms underlying breathing complexity.

    Directory of Open Access Journals (Sweden)

    Agathe Hess

    Full Text Available Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD. COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI, we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL medulla (pre-Bötzinger complex and the caudal VL pons (parafacial group. fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in

  8. 补肺健脾方对慢性阻塞性肺疾病大鼠膈神经放电和膈肌功能的影响%Effects of Bufei Jianpi Recipe on the Diaphragrnatic Neural Discharge and the Dlaphragrnatic Muscle Function In Rats With Chronic Obstructive Pulmonery Disease

    Institute of Scientific and Technical Information of China (English)

    李素云; 李亚; 李建生; 邓丽; 田燕歌; 姜素丽; 王英

    2012-01-01

    Objective To observe the effects of Bufei Jianpi Recipe (BJR) on the diaphragmatic neural discharge and the diaphragmatic muscle function in rats with chronic obstructive pulmonary disease (COPD). Methods Rats were randomly divided into the normal control group, the model group, the high dose BJR group (9.68 g/kg · d-1), the medium dose BJR group (4. 84 g/kg · d-1), the low dose BJR group (2.42 g/kg · d-1), and the aminophyline group (2.3 mg/kg · d-1). The stable phase COPD rat model was prepared using repeated smoke inhalations and bacterial infections. The high, medium, and low dose BJR and aminophyline was respectively administered to rats from the ninth week to the twentieth week. The sampling was taken. The lung function, diaphragmatic neural discharge time (Td), and diaphragmatic neural discharge interval (Tdi), diaphragmatic neural discharge range (Rd), diaphragmatic neural discharge area (Ad), expiratory time (Tex), inspiratory time (Tin), respiratory rate (RR), respiratory excursion (RE), respiratory area (RA), and diaphragmatic muscular tension and endurance were detected. Results Compared with the normal control group, the tidal volume (TV), peak expiratory flow (PEF), and 50% tidal volume expiratory flow (EF50) significantly decreased in the model group (P < 0.01). Td, Tdi, Tex, and Tin were significantly prolonged (P < 0.05, P < 0.01). Ad, Rd, RR, RE, RA, diaphragmatic muscular tension and endurance significantly decreased (P< 0.05, P<0.01). The ratio of type Ⅰ and Ⅱ A diaphragmatic fibers significantly increased and type D B significantly decreased (P<0.01). The activity of ATP decreased and the activity of SDH increased (P<0.01). The aforesaid indices were improved to different degrees in BJR groups, especially in the high dose BJR group and the medium dose BJR group (P<0.05, P<0.01). Conclusions BJR could significantly improve the diaphragmatic neural discharge and the diaphragmatic muscle function. Its efficacy was better than that of

  9. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  10. Morphological neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, G.X.; Sussner, P. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-31

    The theory of artificial neural networks has been successfully applied to a wide variety of pattern recognition problems. In this theory, the first step in computing the next state of a neuron or in performing the next layer neural network computation involves the linear operation of multiplying neural values by their synaptic strengths and adding the results. Thresholding usually follows the linear operation in order to provide for nonlinearity of the network. In this paper we introduce a novel class of neural networks, called morphological neural networks, in which the operations of multiplication and addition are replaced by addition and maximum (or minimum), respectively. By taking the maximum (or minimum) of sums instead of the sum of products, morphological network computation is nonlinear before thresholding. As a consequence, the properties of morphological neural networks are drastically different than those of traditional neural network models. In this paper we consider some of these differences and provide some particular examples of morphological neural network.

  11. Artificial Neural Networks

    OpenAIRE

    Chung-Ming Kuan

    2006-01-01

    Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods.

  12. CSAHi study: Validation of multi-electrode array systems (MEA60/2100) for prediction of drug-induced proarrhythmia using human iPS cell-derived cardiomyocytes -assessment of inter-facility and cells lot-to-lot-variability.

    Science.gov (United States)

    Nozaki, Yumiko; Honda, Yayoi; Watanabe, Hitoshi; Saiki, Shota; Koyabu, Kiyotaka; Itoh, Tetsuji; Nagasawa, Chiho; Nakamori, Chiaki; Nakayama, Chiaki; Iwasaki, Hiroshi; Suzuki, Shinobu; Washio, Ikumi; Takahashi, Etsushi; Miyamoto, Kaori; Yamanishi, Atsuhiro; Endo, Hiroko; Shinozaki, Junko; Nogawa, Hisashi; Kunimatsu, Takeshi

    2016-06-01

    In vitro screening of hERG channels are recommended under ICH S7B guidelines to predict drug-induced QT prolongation and Torsade de Pointes (TdP), whereas proarrhythmia is known to be evoked by blockage of other ion channels involved in cardiac contraction and compensation mechanisms. A consortium for drug safety assessment using human iPS cells-derived cardiomyocytes (hiPS-CMs), CSAHi, has been organized to establish a novel in vitro test system that would enable better prediction of drug-induced proarrhythmia and QT prolongation. Here we report the inter-facility and cells lot-to-lot variability evaluated with FPDc (corrected field potential duration), FPDc10 (10% FPDc change concentration), beat rate and incidence of arrhythmia-like waveform or arrest on hiPS-CMs in a multi-electrode array system. Arrhythmia-like waveforms were evident for all test compounds, other than chromanol 293B, that evoked FPDc prolongation in this system and are reported to induce TdP in clinical practice. There was no apparent cells lot-to-lot variability, while inter-facility variabilities were limited within ranges from 3.9- to 20-folds for FPDc10 and about 10-folds for the minimum concentration inducing arrhythmia-like waveform or arrests. In conclusion, the new assay model reported here would enable accurate prediction of a drug potential for proarrhythmia.

  13. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

  14. READING A NEURAL CODE

    NARCIS (Netherlands)

    BIALEK, W; RIEKE, F; VANSTEVENINCK, RRD; WARLAND, D

    1991-01-01

    Traditional approaches to neural coding characterize the encoding of known stimuli in average neural responses. Organisms face nearly the opposite task - extracting information about an unknown time-dependent stimulus from short segments of a spike train. Here the neural code was characterized from

  15. Generalized classifier neural network.

    Science.gov (United States)

    Ozyildirim, Buse Melis; Avci, Mutlu

    2013-03-01

    In this work a new radial basis function based classification neural network named as generalized classifier neural network, is proposed. The proposed generalized classifier neural network has five layers, unlike other radial basis function based neural networks such as generalized regression neural network and probabilistic neural network. They are input, pattern, summation, normalization and output layers. In addition to topological difference, the proposed neural network has gradient descent based optimization of smoothing parameter approach and diverge effect term added calculation improvements. Diverge effect term is an improvement on summation layer calculation to supply additional separation ability and flexibility. Performance of generalized classifier neural network is compared with that of the probabilistic neural network, multilayer perceptron algorithm and radial basis function neural network on 9 different data sets and with that of generalized regression neural network on 3 different data sets include only two classes in MATLAB environment. Better classification performance up to %89 is observed. Improved classification performances proved the effectivity of the proposed neural network.

  16. Artificial neural interfaces for bionic cardiovascular treatments.

    Science.gov (United States)

    Kawada, Toru; Sugimachi, Masaru

    2009-01-01

    An artificial nerve, in the broad sense, may be conceptualized as a physical and logical interface system that reestablishes the information traffic between the central nervous system and peripheral organs. Studies on artificial nerves targeting the autonomic nervous system are in progress to explore new treatment strategies for several cardiovascular diseases. In this article, we will review our research targeting the autonomic nervous system to treat cardiovascular diseases. First, we identified the rule for decoding native sympathetic nerve activity into a heart rate using transfer function analysis, and established a framework for a neurally regulated cardiac pacemaker. Second, we designed a bionic baroreflex system to restore the baroreflex buffering function using electrical stimulation of the celiac ganglion in a rat model of orthostatic hypotension. Third, based on the hypothesis that autonomic imbalance aggravates chronic heart failure, we implanted a neural interface into the right vagal nerve and demonstrated that intermittent vagal stimulation significantly improved the survival rate in rats with chronic heart failure following myocardial infarction. Although several practical problems need to be resolved, such as those relating to the development of electrodes feasible for long-term nerve activity recording, studies of artificial neural interfaces with the autonomic nervous system have great possibilities in the field of cardiovascular treatment. We expect further development of artificial neural interfaces as novel strategies to cope with cardiovascular diseases resistant to conventional therapeutics.

  17. Neural induction and factors that stabilize a neural fate

    OpenAIRE

    Rogers, Crystal; Moody, Sally A.; Casey, Elena

    2009-01-01

    The neural ectoderm of vertebrates forms when the BMP signaling pathway is suppressed. Herein we review the molecules that directly antagonize extracellular BMP and the signaling pathways that further contribute to reduce BMP activity in the neural ectoderm. Downstream of neural induction, a large number of “neural fate stabilizing” (NFS) transcription factors are expressed in the presumptive neural ectoderm, developing neural tube, and ultimately in neural stem cells. Herein we review what i...

  18. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  19. [Chronicity, chronicization, systematization of delusions].

    Science.gov (United States)

    Trapet, P; Fernandez, C; Galtier, M C; Gisselmann, A

    1984-05-01

    Chronicity in psychopathology is indicative of a term, a decay. Chronicization only leads the way to this term. Here, chronicization is taken literally as an inscription in the time course of delusions. The mechanism of systematization seems to be a central mark in the approach to chronic delusions. It is not an alienation or an irreversible closing but an attempted accommodation with reality in the life of psychotic subjects, irrespective of the delusional structure. The role of therapy and drug treatment as a follow-up may in that case assume another meaning.

  20. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Froeling, Fieke EM

    2008-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas owing to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects 3–9 people in 100,000; 70% of cases are alcohol-induced.

  1. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Kadaba, Raghu

    2011-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas due to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects between 3 and 9 people in 100,000; 70% of cases are alcohol-induced.

  2. Chaotic diagonal recurrent neural network

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  3. [Neurosurgical treatment of chronic pain].

    Science.gov (United States)

    Fontaine, D; Blond, S; Mertens, P; Lanteri-Minet, M

    2015-02-01

    Neurosurgical treatment of pain used two kind of techniques: 1) Lesional techniques interrupt the transmission of nociceptive neural input by lesionning the nociceptive pathways (drezotomy, cordotomy, tractotomy…). They are indicated to treat morphine-resistant cancer pain and few cases of selected neuropathic pain. 2) Neuromodulation techniques try to decrease pain by reinforcing inhibitory and/or to limit activatory mechanisms. Chronic electrical stimulation of the nervous system (peripheral nerve stimulation, spinal cord stimulation, motor cortex stimulation…) is used to treat chronic neuropathic pain. Intrathecal infusion of analgesics (morphine, ziconotide…), using implantable pumps, allows to increase their efficacy and to reduce their side effects. These techniques can improve, sometimes dramatically, selected patients with severe and chronic pain, refractory to all other treatments. The quality of the analgesic outcome depends on the relevance of the indications.

  4. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  5. The neuro-glial properties of adipose-derived adult stromal (ADAS cells are not regulated by Notch 1 and are not derived from neural crest lineage.

    Directory of Open Access Journals (Sweden)

    Philip C Wrage

    Full Text Available We investigated whether adipose-derived adult stromal (ADAS are of neural crest origin and the extent to which Notch 1 regulates their growth and differentiation. Mouse ADAS cells cultured in media formulated for neural stem cells (NSC displayed limited capacity for self-renewal, clonogenicity, and neurosphere formation compared to NSC from the subventricular zone in the hippocampus. Although ADAS cells expressed Nestin, GFAP, NSE and Tuj1 in vitro, exposure to NSC differentiation supplements did not induce mature neuronal marker expression. In contrast, in mesenchymal stem cell (MSC media, ADAS cells retained their ability to proliferate and differentiate beyond 20 passages and expressed high levels of Nestin. In neuritizing cocktails, ADAS cells extended processes, downregulated Nestin expression, and displayed depolarization-induced Ca(2+ transients but no spontaneous or evoked neural network activity on Multi-Electrode Arrays. Deletion of Notch 1 in ADAS cell cultures grown in NSC proliferation medium did not significantly alter their proliferative potential in vitro or the differentiation-induced downregulation of Nestin. Co-culture of ADAS cells with fibroblasts that stably expressed the Notch ligand Jagged 1 or overexpression of the Notch intracellular domain (NICD did not alter ADAS cell growth, morphology, or cellular marker expression. ADAS cells did not display robust expression of neural crest transcription factors or genes (Sox, CRABP2, and TH; and lineage tracing analyses using Wnt1-Cre;Rosa26R-lacZ or -EYFP reporter mice confirmed that fewer than 2% of the ADAS cell population derived from a Wnt1-positive population during development. In summary, although media formulations optimized for MSCs or NSCs enable expansion of mouse ADAS cells in vitro, we find no evidence that these cells are of neural crest origin, that they can undergo robust terminal differentiation into functionally mature neurons, and that Notch 1 is likely to be

  6. 慢性炎症性脱髓鞘性多发性神经病的神经电图与肌电图研究%Study the Neural Electrical Diagram and Electromyography in Chronic Inflammatory Demyelinating Multiple Psycho

    Institute of Scientific and Technical Information of China (English)

    杨颖颖

    2016-01-01

    目的:分析在患有慢性炎症脱髓鞘多发神经病患者的临床诊断和治疗中,神经电图与肌电图的相关情况。方法选择我院2015年4月~2016年4月收治的21例慢性炎症脱髓鞘多发神经病患者作为实验的研究组,再选择同期到我院接受体检的正常人作为对照组,对两组对象分别进行神经电图与肌电图检测,分析两组对象的相关指标。结果研究组的各项指标与对照组相比差异具有统计学意义(P<0.05)。结论在慢性炎症脱髓鞘多发神经病患者诊治中,神经电图与肌电图值得应用。%ObjectiveTo analyze the clinical diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy patients,related electroneurography and electromyography.MethodsIn our hospital from April 2015 to April 2016,21 cases of chronic inflammatory demyelinating polyneuropathy patients were treated as experimental study group,normal people over to our hospital for physical examination selected as the control group,the subjects of two groups were electroneurography and electromyography detection,analysis of the relevant indicators of the two groups.Results The indexes compared with the control group,the difference was statisticaly significant(P<0.05). Conclusion In the treatment of chronic inflammatory demyelinating polyneuropathy patients.

  7. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

  8. Neural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

  9. Miniaturized neural interfaces and implants

    Science.gov (United States)

    Stieglitz, Thomas; Boretius, Tim; Ordonez, Juan; Hassler, Christina; Henle, Christian; Meier, Wolfgang; Plachta, Dennis T. T.; Schuettler, Martin

    2012-03-01

    Neural prostheses are technical systems that interface nerves to treat the symptoms of neurological diseases and to restore sensory of motor functions of the body. Success stories have been written with the cochlear implant to restore hearing, with spinal cord stimulators to treat chronic pain as well as urge incontinence, and with deep brain stimulators in patients suffering from Parkinson's disease. Highly complex neural implants for novel medical applications can be miniaturized either by means of precision mechanics technologies using known and established materials for electrodes, cables, and hermetic packages or by applying microsystems technologies. Examples for both approaches will be introduced and discussed. Electrode arrays for recording of electrocorticograms during presurgical epilepsy diagnosis have been manufactured using approved materials and a marking laser to achieve an integration density that is adequate in the context of brain machine interfaces, e.g. on the motor cortex. Microtechnologies have to be used for further miniaturization to develop polymer-based flexible and light weighted electrode arrays to interface the peripheral and central nervous system. Polyimide as substrate and insulation material will be discussed as well as several application examples for nerve interfaces like cuffs, filament like electrodes and large arrays for subdural implantation.

  10. Chronic, low-dose rotenone reproduces Lewy neurites found in early stages of Parkinson's disease, reduces mitochondrial movement and slowly kills differentiated SH-SY5Y neural cells

    Directory of Open Access Journals (Sweden)

    Liu Lei

    2008-12-01

    Full Text Available Abstract Background Parkinson's disease, the most common adult neurodegenerative movement disorder, demonstrates a brain-wide pathology that begins pre-clinically with alpha-synuclein aggregates ("Lewy neurites" in processes of gut enteric and vagal motor neurons. Rostral progression into substantia nigra with death of dopamine neurons produces the motor impairment phenotype that yields a clinical diagnosis. The vast majority of Parkinson's disease occurs sporadically, and current models of sporadic Parkinson's disease (sPD can utilize directly infused or systemic neurotoxins. Results We developed a differentiation protocol for human SH-SY5Y neuroblastoma that yielded non-dividing dopaminergic neural cells with long processes that we then exposed to 50 nM rotenone, a complex I inhibitor used in Parkinson's disease models. After 21 days of rotenone, ~60% of cells died. Their processes retracted and accumulated ASYN-(+ and UB-(+ aggregates that blocked organelle transport. Mitochondrial movement velocities were reduced by 8 days of rotenone and continued to decline over time. No cytoplasmic inclusions resembling Lewy bodies were observed. Gene microarray analyses showed that the majority of genes were under-expressed. qPCR analyses of 11 mtDNA-encoded and 10 nDNA-encoded mitochondrial electron transport chain RNAs' relative expressions revealed small increases in mtDNA-encoded genes and lesser regulation of nDNA-encoded ETC genes. Conclusion Subacute rotenone treatment of differentiated SH-SY5Y neuroblastoma cells causes process retraction and partial death over several weeks, slowed mitochondrial movement in processes and appears to reproduce the Lewy neuritic changes of early Parkinson's disease pathology but does not cause Lewy body inclusions. The overall pattern of transcriptional regulation is gene under-expression with minimal regulation of ETC genes in spite of rotenone's being a complex I toxin. This rotenone-SH-SY5Y model in a

  11. Ear infection - chronic

    Science.gov (United States)

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... up. When this happens, infection can occur. A chronic ear infection develops when fluid or an infection ...

  12. Neural Networks: Implementations and Applications

    NARCIS (Netherlands)

    Vonk, E.; Veelenturf, L.P.J.; Jain, L.C.

    1996-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  13. What Are Neural Tube Defects?

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on social media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects are ...

  14. Neural regulation and dynamics of prolactin secretion in the rat.

    NARCIS (Netherlands)

    Wiersma, J.

    1990-01-01

    The subject of this thesis was an investigation of the neural regulation and dynamics of prolactin (Prl) secretion. Experimentation was performed with freely behaving undisturbed male and female rats, chronically fitted with an atrial blood sampling catheter. In some studies rats were also equip

  15. Changes within bursts during learning in dissociated neural networks

    NARCIS (Netherlands)

    Stegenga, Jan; Feber, le Joost; Rutten, Wim L.C.

    2008-01-01

    We have studied the effect of imprinting a new stimulus-response (SR) relationship into a neuronal network cultured on a multi electrode array (MEA). We have used the Conditional Repetitive Stimulation (CRS) algorithm introduced by Shahaf et al in 2004. In this algorithm focal electrical stimulation

  16. Critical Branching Neural Networks

    Science.gov (United States)

    Kello, Christopher T.

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical…

  17. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  18. Is neural Darwinism Darwinism?

    Science.gov (United States)

    van Belle, T

    1997-01-01

    Neural Darwinism is a theory of cognition developed by Gerald Edelman along with George Reeke and Olaf Sporns at Rockefeller University. As its name suggests, neural Darwinism is modeled after biological Darwinism, and its authors assert that the two processes are strongly analogous. both operate on variation in a population, amplifying the more adaptive individuals. However, from a computational perspective, neural Darwinism is quite different from other models of natural selection, such as genetic algorithms. The individuals of neural Darwinism do not replicate, thus robbing the process of the capacity to explore new solutions over time and ultimately reducing it to a random search. Because neural Darwinism does not have the computational power of a truly Darwinian process, it is misleading to label it as such. to illustrate this disparity in adaptive power, one of Edelman's early computer experiments, Darwin I, is revisited, and it is shown that adding replication greatly improves the adaptive power of the system.

  19. [Chronic hepatitis].

    Science.gov (United States)

    Figueroa Barrios, R

    1995-01-01

    Medical literature about chronic hepatitis is reviewed. This unresolving disease caused by viruses, drugs or unknown factors may progress to in cirrhosis and hepatocarcinoma. A classification based on liver biopsy histology into chronic persistent and chronic active types has been largely abandoned and emphasis is placed on recognizing the etiology of the various types. One is associated with continuing hepatitis B virus infection; another is related to chronic hepatitis C virus infection and the third is termed autoinmune, because of the association with positive serum autoantibodies. A fourth type with similar clinical functional and morphologic features is found with some drug reactions. Long term corticoesteroid therapy is usually successful in autoinmune type. Associations between antibodies to liver-kidney microsomes and the hepatitis C virus can cause diagnostic difficulties. Antiviral treatment of chronic hepatitis B and C with interpheron alfa is employed, controlling symptoms and abnormal biochemistry and the progression to cirrhosis and liver cancer in 30 to 40% patients. Alternative therapies or combinations with interpheron are being evaluated waiting for final results.

  20. Multi-electrode array technologies for neuroscience and cardiology

    Science.gov (United States)

    Spira, Micha E.; Hai, Aviad

    2013-02-01

    At present, the prime methodology for studying neuronal circuit-connectivity, physiology and pathology under in vitro or in vivo conditions is by using substrate-integrated microelectrode arrays. Although this methodology permits simultaneous, cell-non-invasive, long-term recordings of extracellular field potentials generated by action potentials, it is 'blind' to subthreshold synaptic potentials generated by single cells. On the other hand, intracellular recordings of the full electrophysiological repertoire (subthreshold synaptic potentials, membrane oscillations and action potentials) are, at present, obtained only by sharp or patch microelectrodes. These, however, are limited to single cells at a time and for short durations. Recently a number of laboratories began to merge the advantages of extracellular microelectrode arrays and intracellular microelectrodes. This Review describes the novel approaches, identifying their strengths and limitations from the point of view of the end users -- with the intention to help steer the bioengineering efforts towards the needs of brain-circuit research.

  1. Neural repair in the adult brain [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Sebastian Jessberger

    2016-02-01

    Full Text Available Acute or chronic injury to the adult brain often results in substantial loss of neural tissue and subsequent permanent functional impairment. Over the last two decades, a number of approaches have been developed to harness the regenerative potential of neural stem cells and the existing fate plasticity of neural cells in the nervous system to prevent tissue loss or to enhance structural and functional regeneration upon injury. Here, we review recent advances of stem cell-associated neural repair in the adult brain, discuss current challenges and limitations, and suggest potential directions to foster the translation of experimental stem cell therapies into the clinic.

  2. Dynamics of neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-05-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

  3. AUV fuzzy neural BDI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The typical BDI (belief desire intention) model of agent is not efficiently computable and the strict logic expression is not easily applicable to the AUV (autonomous underwater vehicle) domain with uncertainties. In this paper, an AUV fuzzy neural BDI model is proposed. The model is a fuzzy neural network composed of five layers: input ( beliefs and desires) , fuzzification, commitment, fuzzy intention, and defuzzification layer. In the model, the fuzzy commitment rules and neural network are combined to form intentions from beliefs and desires. The model is demonstrated by solving PEG (pursuit-evasion game), and the simulation result is satisfactory.

  4. ANT Advanced Neural Tool

    Energy Technology Data Exchange (ETDEWEB)

    Labrador, I.; Carrasco, R.; Martinez, L.

    1996-07-01

    This paper describes a practical introduction to the use of Artificial Neural Networks. Artificial Neural Nets are often used as an alternative to the traditional symbolic manipulation and first order logic used in Artificial Intelligence, due the high degree of difficulty to solve problems that can not be handled by programmers using algorithmic strategies. As a particular case of Neural Net a Multilayer Perception developed by programming in C language on OS9 real time operating system is presented. A detailed description about the program structure and practical use are included. Finally, several application examples that have been treated with the tool are presented, and some suggestions about hardware implementations. (Author) 15 refs.

  5. Chronic gastritis.

    Science.gov (United States)

    Sipponen, Pentti; Maaroos, Heidi-Ingrid

    2015-06-01

    Prevalence of chronic gastritis has markedly declined in developed populations during the past decades. However, chronic gastritis is still one of the most common serious pandemic infections with such severe killing sequelae as peptic ulcer or gastric cancer. Globally, on average, even more than half of people may have a chronic gastritis at present. Helicobacter pylori infection in childhood is the main cause of chronic gastritis, which microbial origin is the key for the understanding of the bizarre epidemiology and course of the disease. A life-long and aggressive inflammation in gastritis results in destruction (atrophic gastritis) of stomach mucosa with time (years and decades). The progressive worsening of atrophic gastritis results subsequently in dysfunctions of stomach mucosa. Atrophic gastritis will finally end up in a permanently acid-free stomach in the most extreme cases. Severe atrophic gastritis and acid-free stomach are the highest independent risk conditions for gastric cancer known so far. In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.

  6. Chronic Bronchitis

    Science.gov (United States)

    ... breathing. You may also have other tests. Chronic bronchitis is a long-term condition that keeps coming back or never goes away completely. If you smoke, it is important to quit. Treatment can help with your symptoms. It often includes ...

  7. Evidence for neuropathic processes in chronic cough.

    Science.gov (United States)

    Niimi, Akio; Chung, Kian Fan

    2015-12-01

    Chronic cough is a very common symptom for which patients seek medical attention but can often be difficult to manage, because associated causes may remain elusive and treatment of any associated causes does not always provide adequate relief. Current antitussives have limited efficacy and undesirable side-effects. Patients with chronic cough typically describe sensory symptoms suggestive of upper airway and laryngeal neural dysfunction. They often report cough triggered by low-level physical and chemical stimuli supporting the recently emerging concept of 'cough hypersensitivity syndrome'. Chronic cough is a neuropathic condition that could be secondary to sensory nerve damage caused by inflammatory, infective and allergic factors. Mechanisms underlying peripheral and central augmentation of the afferent cough pathways have been identified. Successful treatment of chronic cough with agents used for treating neuropathic pain, such as gabapentin and amitriptyline, would also support this concept. Further research of neuropathic cough may lead to the discovery of more effective antitussives in the future.

  8. Neural networks and graph theory

    Institute of Scientific and Technical Information of China (English)

    许进; 保铮

    2002-01-01

    The relationships between artificial neural networks and graph theory are considered in detail. The applications of artificial neural networks to many difficult problems of graph theory, especially NP-complete problems, and the applications of graph theory to artificial neural networks are discussed. For example graph theory is used to study the pattern classification problem on the discrete type feedforward neural networks, and the stability analysis of feedback artificial neural networks etc.

  9. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  10. Critical branching neural networks.

    Science.gov (United States)

    Kello, Christopher T

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical branching and, in doing so, simulates observed scaling laws as pervasive to neural and behavioral activity. These scaling laws are related to neural and cognitive functions, in that critical branching is shown to yield spiking activity with maximal memory and encoding capacities when analyzed using reservoir computing techniques. The model is also shown to account for findings of pervasive 1/f scaling in speech and cued response behaviors that are difficult to explain by isolable causes. Issues and questions raised by the model and its results are discussed from the perspectives of physics, neuroscience, computer and information sciences, and psychological and cognitive sciences.

  11. Neural Oscillators Programming Simplified

    Directory of Open Access Journals (Sweden)

    Patrick McDowell

    2012-01-01

    Full Text Available The neurological mechanism used for generating rhythmic patterns for functions such as swallowing, walking, and chewing has been modeled computationally by the neural oscillator. It has been widely studied by biologists to model various aspects of organisms and by computer scientists and robotics engineers as a method for controlling and coordinating the gaits of walking robots. Although there has been significant study in this area, it is difficult to find basic guidelines for programming neural oscillators. In this paper, the authors approach neural oscillators from a programmer’s point of view, providing background and examples for developing neural oscillators to generate rhythmic patterns that can be used in biological modeling and robotics applications.

  12. Imaging the Neural Symphony.

    Science.gov (United States)

    Svoboda, Karel

    2016-01-01

    Since the start of the new millennium, a method called two-photon microscopy has allowed scientists to peer farther into the brain than ever before. Our author, one of the pioneers in the development of this new technology, writes that "directly observing the dynamics of neural networks in an intact brain has become one of the holy grails of brain research." His article describes the advances that led to this remarkable breakthrough-one that is helping neuroscientists better understand neural networks.

  13. Building a Neural Computer

    OpenAIRE

    1998-01-01

    In the work of [Siegelmann 95] it was showed that Artificial Recursive Neural Networks have the same computing power as Turing machines. A Turing machine can be programmed in a proper high-level language - the language of partial recursive functions. In this paper we present the implementation of a compiler that directly translates high-level Turing machine programs to Artificial Recursive Neural Networks. The application contains a simulator that can be used to test the resulting networks. W...

  14. Neural cryptography with feedback.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  15. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... Information > Children/Pediatric > Chronic Pancreatitis in Children test Chronic Pancreatitis in Children What symptoms would my child ... pancreatitis will develop diabetes in adolescence. Who gets chronic pancreatitis? Those at risk for chronic pancreatitis are ...

  16. Chronic Beryllium Disease

    Science.gov (United States)

    ... Science Education & Training Home Conditions Chronic Beryllium Disease Chronic Beryllium Disease Make an Appointment Find a Doctor ... MD, MSPH, FCCP (February 01, 2016) What is chronic beryllium disease (CBD)? Chronic beryllium disease (CBD) is ...

  17. Chronic motor tic disorder

    Science.gov (United States)

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  18. Chronic Pelvic Pain

    Science.gov (United States)

    ... Education & Events Advocacy For Patients About ACOG Chronic Pelvic Pain Home For Patients Search FAQs Chronic Pelvic Pain ... Pelvic Pain FAQ099, August 2011 PDF Format Chronic Pelvic Pain Gynecologic Problems What is chronic pelvic pain? What ...

  19. Chronic thyroiditis (Hashimoto disease)

    Science.gov (United States)

    Hashimoto thyroiditis; Chronic lymphocytic thyroiditis; Autoimmune thyroiditis; Chronic autoimmune thyroiditis; Lymphadenoid goiter - Hashimoto; Hypothyroidism - Hashimoto; Type 2 polyglandular autoimmune ...

  20. Pain pathoetiology after TBI: neural and nonneural mechanisms.

    Science.gov (United States)

    Walker, William C

    2004-01-01

    Individuals recovering from traumatic brain injury (TBI) frequently experience acute and chronic pain. Their pain experience is the net effect of many interacting and very complex physiologic, biochemical, and psychological mechanisms involving both the peripheral and central nervous system. This article reviews the basics of neural mechanisms and pathways of pain after TBI, and discusses clinical implications. Numerous intracranial and extracranial tissues must be considered in the evaluation of pain after TBI, with the specific mechanism of trauma influencing the anatomic distribution of injuries. The differential diagnosis usually falls into one of the following pathoetiologic classifications: primary or secondary musculoskeletal, vascular, visceral, and neural pain syndromes.

  1. Neural networks in seismic discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F.U.

    1995-01-01

    Neural networks are powerful and elegant computational tools that can be used in the analysis of geophysical signals. At Lawrence Livermore National Laboratory, we have developed neural networks to solve problems in seismic discrimination, event classification, and seismic and hydrodynamic yield estimation. Other researchers have used neural networks for seismic phase identification. We are currently developing neural networks to estimate depths of seismic events using regional seismograms. In this paper different types of network architecture and representation techniques are discussed. We address the important problem of designing neural networks with good generalization capabilities. Examples of neural networks for treaty verification applications are also described.

  2. Memory Consolidation and Neural Substrate of Reward

    Directory of Open Access Journals (Sweden)

    Redolar-Ripoll, Diego

    2012-08-01

    Full Text Available The aim of this report is to analyze the relationships between reward and learning and memory processes. Different studies have described how information about rewards influences behavior and how the brain uses this reward information to control learning and memory processes. Reward nature seems to be processed in different ways by neurons in different brain structures, ranging from the detection and perception of rewards to the use of information about predicted rewards for the control of goal-directed behavior. The neural substrate underling this processing of reward information is a reliable way of improving learning and memory processes. Evidence from several studies indicates that this neural system can facilitate memory consolidation in a wide variety of learning tasks. From a molecular perspective, certain cardinal features of reward have been described as forms of memory. Studies of human addicts and studies in animal models of addiction show that chronic drug exposure produces stable changes in the brain at the cellular and molecular levels that underlie the long-lasting behavioral plasticity associated with addiction. These molecular and cellular adaptations involved in addiction are also implicated in learning and memory processes. Dopamine seems to be a critical common signal to activate different genetic mechanisms that ultimately remodel synapses and circuits. Despite memory is an active and complex process mediated by different brain areas, the neural substrate of reward is able to improve memory consolidation in a several paradigms. We believe that there are many equivalent traits between reward and learning and memory processes.

  3. Rule Extraction:Using Neural Networks or for Neural Networks?

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Zhou

    2004-01-01

    In the research of rule extraction from neural networks, fidelity describes how well the rules mimic the behavior of a neural network while accuracy describes how well the rules can be generalized. This paper identifies the fidelity-accuracy dilemma. It argues to distinguish rule extraction using neural networks and rule extraction for neural networks according to their different goals, where fidelity and accuracy should be excluded from the rule quality evaluation framework, respectively.

  4. Fuzzy Multiresolution Neural Networks

    Science.gov (United States)

    Ying, Li; Qigang, Shang; Na, Lei

    A fuzzy multi-resolution neural network (FMRANN) based on particle swarm algorithm is proposed to approximate arbitrary nonlinear function. The active function of the FMRANN consists of not only the wavelet functions, but also the scaling functions, whose translation parameters and dilation parameters are adjustable. A set of fuzzy rules are involved in the FMRANN. Each rule either corresponding to a subset consists of scaling functions, or corresponding to a sub-wavelet neural network consists of wavelets with same dilation parameters. Incorporating the time-frequency localization and multi-resolution properties of wavelets with the ability of self-learning of fuzzy neural network, the approximation ability of FMRANN can be remarkable improved. A particle swarm algorithm is adopted to learn the translation and dilation parameters of the wavelets and adjusting the shape of membership functions. Simulation examples are presented to validate the effectiveness of FMRANN.

  5. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  6. Neural mechanisms underlying morphine withdrawal in addicted patients: a review

    Directory of Open Access Journals (Sweden)

    Nima Babhadiashar

    2015-06-01

    Full Text Available Morphine is one of the most potent alkaloid in opium, which has substantial medical uses and needs and it is the first active principle purified from herbal source. Morphine has commonly been used for relief of moderate to severe pain as it acts directly on the central nervous system; nonetheless, its chronic abuse increases tolerance and physical dependence, which is commonly known as opiate addiction. Morphine withdrawal syndrome is physiological and behavioral symptoms that stem from prolonged exposure to morphine. A majority of brain regions are hypofunctional over prolonged abstinence and acute morphine withdrawal. Furthermore, several neural mechanisms are likely to contribute to morphine withdrawal. The present review summarizes the literature pertaining to neural mechanisms underlying morphine withdrawal. Despite the fact that morphine withdrawal is a complex process, it is suggested that neural mechanisms play key roles in morphine withdrawal.

  7. Generalized Adaptive Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  8. Neural Network Ensembles

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Salamon, Peter

    1990-01-01

    We propose several means for improving the performance an training of neural networks for classification. We use crossvalidation as a tool for optimizing network parameters and architecture. We show further that the remaining generalization error can be reduced by invoking ensembles of similar...

  9. Chronic inflammatory demyelinating polyneuropathy

    Science.gov (United States)

    Polyneuropathy - chronic inflammatory; CIDP; Chronic inflammatory polyneuropathy; Guillain-Barré - CIDP ... Health care providers also consider CIDP as the chronic form of Guillain-Barré syndrome. The specific triggers ...

  10. Dealing with chronic cancer

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000933.htm Dealing with chronic cancer To use the sharing features on this ... be controlled for a period of time. Controlling Chronic Cancer When you have a chronic cancer, the ...

  11. Chronic sleep disturbance and neural injury: links to neurodegenerative disease

    Directory of Open Access Journals (Sweden)

    Abbott SM

    2016-01-01

    Full Text Available Sabra M Abbott,1 Aleksandar Videnovic21Department of Neurology, Northwestern Feinberg School of Medicine, Chicago, IL, USA; 2Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Abstract: Sleep–wake disruption is frequently observed and often one of the earliest reported symptoms of many neurodegenerative disorders. This provides insight into the underlying pathophysiology of these disorders, as sleep–wake abnormalities are often accompanied by neurodegenerative or neurotransmitter changes. However, in addition to being a symptom of the underlying neurodegenerative condition, there is also emerging evidence that sleep disturbance itself may contribute to the development and facilitate the progression of several of these disorders. Due to its impact both as an early symptom and as a potential factor contributing to ongoing neurodegeneration, the sleep–wake cycle is an ideal target for further study for potential interventions not only to lessen the burden of these diseases but also to slow their progression. In this review, we will highlight the sleep phenotypes associated with some of the major neurodegenerative disorders, focusing on the circadian disruption associated with Alzheimer’s disease, the rapid eye movement behavior disorder and sleep fragmentation associated with Parkinson’s disease, and the insomnia and circadian dysregulation associated with Huntington’s disease. Keywords: sleep, neurodegeneration, Alzheimer's disease, Parkinson's disease, Huntington's disease

  12. Novel flexible Parylene neural probe with 3D sheath structure for enhancing tissue integration.

    Science.gov (United States)

    Kuo, Jonathan T W; Kim, Brian J; Hara, Seth A; Lee, Curtis D; Gutierrez, Christian A; Hoang, Tuan Q; Meng, Ellis

    2013-02-21

    A Parylene C neural probe with a three dimensional sheath structure was designed, fabricated, and characterized. Multiple platinum (Pt) electrodes for recording neural signals were fabricated on both inner and outer surfaces of the sheath structure. Thermoforming of Parylene was used to create the three dimensional sheath structures from flat surface micromachined microchannels using solid microwires as molds. Benchtop electrochemical characterization was performed on the thin film Pt electrodes using cyclic voltammetry and electrochemical impedance spectroscopy and showed that electrodes possessed low impedances suitable for neuronal recordings. A procedure for implantation of the neural probe was developed and successfully demonstrated in vitro into an agarose brain tissue model. The electrode-lined sheath will be decorated with eluting neurotrophic factors to promote in vivo neural tissue ingrowth post-implantation. These features will enhance tissue integration and improve recording quality towards realizing reliable chronic neural interfaces.

  13. Chronic mucus hypersecretion

    DEFF Research Database (Denmark)

    Harmsen, L; Thomsen, S F; Sylvan Ingebrigtsen, Truls;

    2010-01-01

    Chronic mucus hypersecretion (CMH) is a common condition in patients with chronic respiratory diseases. Little is known about the incidence, prevalence and determinants of CMH in younger individuals....

  14. Neural dynamics based on the recognition of neural fingerprints

    Directory of Open Access Journals (Sweden)

    José Luis eCarrillo-Medina

    2015-03-01

    Full Text Available Experimental evidence has revealed the existence of characteristic spiking features in different neural signals, e.g. individual neural signatures identifying the emitter or functional signatures characterizing specific tasks. These neural fingerprints may play a critical role in neural information processing, since they allow receptors to discriminate or contextualize incoming stimuli. This could be a powerful strategy for neural systems that greatly enhances the encoding and processing capacity of these networks. Nevertheless, the study of information processing based on the identification of specific neural fingerprints has attracted little attention. In this work, we study (i the emerging collective dynamics of a network of neurons that communicate with each other by exchange of neural fingerprints and (ii the influence of the network topology on the self-organizing properties within the network. Complex collective dynamics emerge in the network in the presence of stimuli. Predefined inputs, i.e. specific neural fingerprints, are detected and encoded into coexisting patterns of activity that propagate throughout the network with different spatial organization. The patterns evoked by a stimulus can survive after the stimulation is over, which provides memory mechanisms to the network. The results presented in this paper suggest that neural information processing based on neural fingerprints can be a plausible, flexible and powerful strategy.

  15. Chronic urticaria

    Directory of Open Access Journals (Sweden)

    Sandeep Sachdeva

    2011-01-01

    Full Text Available Chronic urticaria (CU is a disturbing allergic condition of the skin. Although frequently benign, it may sometimes be a red flag sign of a serious internal disease. A multitude of etiologies have been implicated in the causation of CU, including physical, infective, vasculitic, psychological and idiopathic. An autoimmune basis of most of the ′idiopathic′ forms is now hypothesized. Histamine released from mast cells is the major effector in pathogenesis and it is clinically characterized by wheals that have a tendency to recur. Laboratory investigations aimed at a specific etiology are not always conclusive, though may be suggestive of an underlying condition. A clinical search for associated systemic disease is strongly advocated under appropriate circumstances. The mainstay of treatment remains H1 antihistaminics. These may be combined with complementary pharmacopeia in the form of H2 blockers, doxepin, nifedipine and leukotriene inhibitors. More radical therapy in the form of immunoglobulins, plasmapheresis and cyclophosphamide may be required for recalcitrant cases. Autologous transfusion and alternative remedies like acupuncture have prospects for future. A stepwise management results in favorable outcomes. An update on CU based on our experience with patients at a tertiary care centre is presented.

  16. Effect of expiratory load on neural inspiratory drive

    Institute of Scientific and Technical Information of China (English)

    XIAO Si-chang; LU Yi-rong; GUO Hong-xi; QIU Zhi-hui; LUO Yuan-ming

    2012-01-01

    Background Neural respiratory drive is usually measured during inspiration,even in patients with chronic obstructive pulmonary disease (COPD) in whom the primary physiological deficit is expiratory flow limitation.The purpose of the study was to test the hypothesis that inspiratory muscle neural respiratory drive could be used to assess expiratory load.Methods Ten healthy young men,(26±4) years old,were asked to expire through a tube immersed in water where an expiratory load was required.The load was judged by the depth of the tube in water and the different loads (0 cmH2O,10 cmH2O,20 cmH2O and 30 cmH2O) were randomly introduced.Each expiratory load lasted for 3-5 minutes and inspiration was unimpeded throughout.Diaphragm electromyogram (EMG) and transdiaphragmatic pressure were recorded by a catheter with 10 metal coils and two balloons.Incremental cycle exercise with and without an expiratory load at 30 cmH2O was also performed.Results Neural drive during expiratory loaded breathing was larger than during unloaded breathing but neural drive did not increase proportionally with increasing expiratory load; neural drive during expiratory loading at 0,10,20 and 30 cmH2O was (10.1±3.1) μV,(16.7±7.3) μV,(18.4±10.7) μV and (22.9±13.2) μV,respectively.Neural drive as a percentage of maximum at the end of exercise with or without load was similar ((57.4±11.0)% max vs.(62.7±16.4)% max,P >0.05).Conclusion Neural respiratory drive measured at inspiration does not accurately quantify expiratory load either at rest or during exercise.

  17. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  18. Quantum Neural Networks

    CERN Document Server

    Gupta, S; Gupta, Sanjay

    2002-01-01

    This paper initiates the study of quantum computing within the constraints of using a polylogarithmic ($O(\\log^k n), k\\geq 1$) number of qubits and a polylogarithmic number of computation steps. The current research in the literature has focussed on using a polynomial number of qubits. A new mathematical model of computation called \\emph{Quantum Neural Networks (QNNs)} is defined, building on Deutsch's model of quantum computational network. The model introduces a nonlinear and irreversible gate, similar to the speculative operator defined by Abrams and Lloyd. The precise dynamics of this operator are defined and while giving examples in which nonlinear Schr\\"{o}dinger's equations are applied, we speculate on its possible implementation. The many practical problems associated with the current model of quantum computing are alleviated in the new model. It is shown that QNNs of logarithmic size and constant depth have the same computational power as threshold circuits, which are used for modeling neural network...

  19. Analysis of neural data

    CERN Document Server

    Kass, Robert E; Brown, Emery N

    2014-01-01

    Continual improvements in data collection and processing have had a huge impact on brain research, producing data sets that are often large and complicated. By emphasizing a few fundamental principles, and a handful of ubiquitous techniques, Analysis of Neural Data provides a unified treatment of analytical methods that have become essential for contemporary researchers. Throughout the book ideas are illustrated with more than 100 examples drawn from the literature, ranging from electrophysiology, to neuroimaging, to behavior. By demonstrating the commonality among various statistical approaches the authors provide the crucial tools for gaining knowledge from diverse types of data. Aimed at experimentalists with only high-school level mathematics, as well as computationally-oriented neuroscientists who have limited familiarity with statistics, Analysis of Neural Data serves as both a self-contained introduction and a reference work.

  20. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

  1. Compressing Convolutional Neural Networks

    OpenAIRE

    Chen, Wenlin; Wilson, James T.; Tyree, Stephen; Weinberger, Kilian Q.; Chen, Yixin

    2015-01-01

    Convolutional neural networks (CNN) are increasingly used in many areas of computer vision. They are particularly attractive because of their ability to "absorb" great quantities of labeled data through millions of parameters. However, as model sizes increase, so do the storage and memory requirements of the classifiers. We present a novel network architecture, Frequency-Sensitive Hashed Nets (FreshNets), which exploits inherent redundancy in both convolutional layers and fully-connected laye...

  2. Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kapil Nahar

    2012-12-01

    Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information.The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems.Ann’s, like people, learn by example.

  3. Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kapil Nahar

    2012-12-01

    Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information. The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems. Ann’s, like people, learn by example.

  4. Neural networks for triggering

    Energy Technology Data Exchange (ETDEWEB)

    Denby, B. (Fermi National Accelerator Lab., Batavia, IL (USA)); Campbell, M. (Michigan Univ., Ann Arbor, MI (USA)); Bedeschi, F. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy)); Chriss, N.; Bowers, C. (Chicago Univ., IL (USA)); Nesti, F. (Scuola Normale Superiore, Pisa (Italy))

    1990-01-01

    Two types of neural network beauty trigger architectures, based on identification of electrons in jets and recognition of secondary vertices, have been simulated in the environment of the Fermilab CDF experiment. The efficiencies for B's and rejection of background obtained are encouraging. If hardware tests are successful, the electron identification architecture will be tested in the 1991 run of CDF. 10 refs., 5 figs., 1 tab.

  5. Coupled Neural Associative Memories

    OpenAIRE

    Karbasi, Amin; Salavati, Amir Hesam; Shokrollahi, Amin

    2013-01-01

    We propose a novel architecture to design a neural associative memory that is capable of learning a large number of patterns and recalling them later in presence of noise. It is based on dividing the neurons into local clusters and parallel plains, very similar to the architecture of the visual cortex of macaque brain. The common features of our proposed architecture with those of spatially-coupled codes enable us to show that the performance of such networks in eliminating noise is drastical...

  6. Progress in neural plasticity

    Institute of Scientific and Technical Information of China (English)

    POO; Mu-Ming

    2010-01-01

    One of the properties of the nervous system is the use-dependent plasticity of neural circuits.The structure and function of neural circuits are susceptible to changes induced by prior neuronal activity,as reflected by short-and long-term modifications of synaptic efficacy and neuronal excitability.Regarded as the most attractive cellular mechanism underlying higher cognitive functions such as learning and memory,activity-dependent synaptic plasticity has been in the spotlight of modern neuroscience since 1973 when activity-induced long-term potentiation(LTP) of hippocampal synapses was first discovered.Over the last 10 years,Chinese neuroscientists have made notable contributions to the study of the cellular and molecular mechanisms of synaptic plasticity,as well as of the plasticity beyond synapses,including activity-dependent changes in intrinsic neuronal excitability,dendritic integration functions,neuron-glia signaling,and neural network activity.This work highlight some of these significant findings.

  7. Trimaran Resistance Artificial Neural Network

    Science.gov (United States)

    2011-01-01

    11th International Conference on Fast Sea Transportation FAST 2011, Honolulu, Hawaii, USA, September 2011 Trimaran Resistance Artificial Neural Network Richard...Trimaran Resistance Artificial Neural Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e... Artificial Neural Network and is restricted to the center and side-hull configurations tested. The value in the parametric model is that it is able to

  8. Chronic pain after hysterectomy

    DEFF Research Database (Denmark)

    Brandsborg, B.; Nikolajsen, L.; Kehlet, H.;

    2008-01-01

    BACKGROUND: Chronic pain is a well-known adverse effect of surgery, but the risk of chronic pain after gynaecological surgery is less established. METHOD: This review summarizes studies on chronic pain following hysterectomy. The underlying mechanisms and risk factors for the development of chronic...... post-hysterectomy pain are discussed. RESULTS AND CONCLUSION: Chronic pain is reported by 5-32% of women after hysterectomy. A guideline is proposed for future prospective studies Udgivelsesdato: 2008/3...

  9. Chronic pain after hysterectomy

    DEFF Research Database (Denmark)

    Brandsborg, B; Nikolajsen, L; Kehlet, Henrik;

    2008-01-01

    BACKGROUND: Chronic pain is a well-known adverse effect of surgery, but the risk of chronic pain after gynaecological surgery is less established. METHOD: This review summarizes studies on chronic pain following hysterectomy. The underlying mechanisms and risk factors for the development of chronic...... post-hysterectomy pain are discussed. RESULTS AND CONCLUSION: Chronic pain is reported by 5-32% of women after hysterectomy. A guideline is proposed for future prospective studies. Udgivelsesdato: 2008-Mar...

  10. [Artificial neural networks in Neurosciences].

    Science.gov (United States)

    Porras Chavarino, Carmen; Salinas Martínez de Lecea, José María

    2011-11-01

    This article shows that artificial neural networks are used for confirming the relationships between physiological and cognitive changes. Specifically, we explore the influence of a decrease of neurotransmitters on the behaviour of old people in recognition tasks. This artificial neural network recognizes learned patterns. When we change the threshold of activation in some units, the artificial neural network simulates the experimental results of old people in recognition tasks. However, the main contributions of this paper are the design of an artificial neural network and its operation inspired by the nervous system and the way the inputs are coded and the process of orthogonalization of patterns.

  11. Neural regulation of intestinal nutrient absorption.

    Science.gov (United States)

    Mourad, Fadi H; Saadé, Nayef E

    2011-10-01

    The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.

  12. Design considerations for miniaturized optical neural probes

    Science.gov (United States)

    Rudmann, Linda; Ordonez, Juan S.; Stieglitz, Thomas

    2016-03-01

    Neural probes are designed to selectively record from or stimulate nerve cells. In optogenetics it is desirable to build miniaturized and long-term stable optical neural probes, in which the light sources can be directly and chronically implanted into the animals to allow free movement and behavior. Because of the size and the beam shape of the available light sources, it is difficult to target single cells as well as spatially localized networks. We therefore investigated design considerations for packages, which encapsulate the light source hermetically and have integrated hemispherical lens structures that enable to focus the light onto the desired region, by optical simulations. Integration of a biconvex lens into the package lid (diameter = 300 μm, material: silicon carbide) increased the averaged absolute irradiance ηA by 298 % compared to a system without a lens and had a spot size of around 120 μm. Solely integrating a plano-convex lens (same diameter and material) results in an ηA of up to 227 %.

  13. [Chronic otitis mediaChronic Otitis Media].

    Science.gov (United States)

    Kohles, N; Schulz, T; Eßer, D

    2015-11-01

    There are 2 different kinds of chronic otitis media: Otitis media chronica mesotympanalis and otitis media chronica epitympanalis (cholesteatoma). The incidence of chronic otitis media as reported in literature differs in a wide range. The incidence rates vary between 0.45 and 46%. Both, otitis media chronica mesotympanalis and cholesteatoma, lead to eardrum perforation due to lengthy and recurring inflammations. Furthermore, chronic otitis media is characterized by frequently recurring otorrhea and conductive hearing loss.

  14. via dynamic neural networks

    Directory of Open Access Journals (Sweden)

    J. Reyes-Reyes

    2000-01-01

    Full Text Available In this paper, an adaptive technique is suggested to provide the passivity property for a class of partially known SISO nonlinear systems. A simple Dynamic Neural Network (DNN, containing only two neurons and without any hidden-layers, is used to identify the unknown nonlinear system. By means of a Lyapunov-like analysis the new learning law for this DNN, guarantying both successful identification and passivation effects, is derived. Based on this adaptive DNN model, an adaptive feedback controller, serving for wide class of nonlinear systems with an a priori incomplete model description, is designed. Two typical examples illustrate the effectiveness of the suggested approach.

  15. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  16. 5-HT2C受体亚型参与易化大鼠内嗅区-海马通路的突触传递:平面微电极阵列记录技术研究%Facilitation of synaptic transmission and connections of entorhinal-hippocampal pathway by 5-HT2C receptor subtype: multi-electrode array recordings

    Institute of Scientific and Technical Information of China (English)

    许燕; 金建慧; 王燕; 王蕊蕊; 李震; 陈军

    2012-01-01

    Using 64-channels (8 × 8) multi-electrode array technique (MED-64 system), the modulatory actions of 5-hydroxytryptam-ine (5-HT) 2C receptor subtype on the entorhinal (EC)-hippocampal synaptic transmission and connections were studied. One of freshly dissociated acute hippocampal slices of rats which was placed on the MED-64 probe, was subject to constant perfusion with oxygenated artificial cerebrospinal fluid (ACSF, 95% O2 and 5% CO2). Two hours after ACSF incubation, simultaneous multi-site electrophysiological recordings were performed. One electrode was selected to be used for perforant path (PP) stimulation, and the remaining 63 electrodes were used for recordings of network field excitatory postsynaptic potentials (fEPSPs) within both CA1 and dentate gyms (DG) that have been previously proved to be mediated by glutamate non-NMDA receptors. After stability of network fEPSPs was achieved, (±)-l(2, 5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI, an agonist of 5-HT2C receptor subtype), or SB242084 (6-Chloro-2,3-dihydro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-lH-indole-l-carboxyamide dihy-drochloride hydrate) (a selective antagonist of 5-HT2C receptor subtype) was applied for 10 min perfusion, respectively. Two-dimensional current source density (2D-CSD) analysis was also transformed by bilinear interpolation at each point of the 64 electrodes for spatial imaging of the fEPSP network responses. Based upon the polarities of fEPSP and 2D-CSD imaging, it was clearly shown that synaptic activations were evoked to occur within the molecular layer of DG and pyramidal cell layer of CA1 by the PP stimulation in which negative-going field potentials and current sink (blue) could be recorded. While, positive-going field potentials and current source (yellow) were mainly localized within the granule cell layer and hilus of DG and alveus of CA1, reflecting spread of electrical signals derived from depolarized region toward CA3 area or subiculum

  17. The Neural Support Vector Machine

    NARCIS (Netherlands)

    Wiering, Marco; van der Ree, Michiel; Embrechts, Mark; Stollenga, Marijn; Meijster, Arnold; Nolte, A; Schomaker, Lambertus

    2013-01-01

    This paper describes a new machine learning algorithm for regression and dimensionality reduction tasks. The Neural Support Vector Machine (NSVM) is a hybrid learning algorithm consisting of neural networks and support vector machines (SVMs). The output of the NSVM is given by SVMs that take a centr

  18. Neural Networks for Optimal Control

    DEFF Research Database (Denmark)

    Sørensen, O.

    1995-01-01

    Two neural networks are trained to act as an observer and a controller, respectively, to control a non-linear, multi-variable process.......Two neural networks are trained to act as an observer and a controller, respectively, to control a non-linear, multi-variable process....

  19. The Neural Web of War

    NARCIS (Netherlands)

    Kennis, M.

    2016-01-01

    The aim of this thesis was to gain more insight in the neural network alterations that may underlie PTSD and trauma-focused therapy outcome. To investigate TheNeural Web of War brain scans of healthy civilians (n=26), and veterans with (n=58) and without (n=29) PTSD were assessed. Structural and fun

  20. Analysis of neural networks

    CERN Document Server

    Heiden, Uwe

    1980-01-01

    The purpose of this work is a unified and general treatment of activity in neural networks from a mathematical pOint of view. Possible applications of the theory presented are indica­ ted throughout the text. However, they are not explored in de­ tail for two reasons : first, the universal character of n- ral activity in nearly all animals requires some type of a general approach~ secondly, the mathematical perspicuity would suffer if too many experimental details and empirical peculiarities were interspersed among the mathematical investigation. A guide to many applications is supplied by the references concerning a variety of specific issues. Of course the theory does not aim at covering all individual problems. Moreover there are other approaches to neural network theory (see e.g. Poggio-Torre, 1978) based on the different lev­ els at which the nervous system may be viewed. The theory is a deterministic one reflecting the average be­ havior of neurons or neuron pools. In this respect the essay is writt...

  1. Neural networks in astronomy.

    Science.gov (United States)

    Tagliaferri, Roberto; Longo, Giuseppe; Milano, Leopoldo; Acernese, Fausto; Barone, Fabrizio; Ciaramella, Angelo; De Rosa, Rosario; Donalek, Ciro; Eleuteri, Antonio; Raiconi, Giancarlo; Sessa, Salvatore; Staiano, Antonino; Volpicelli, Alfredo

    2003-01-01

    In the last decade, the use of neural networks (NN) and of other soft computing methods has begun to spread also in the astronomical community which, due to the required accuracy of the measurements, is usually reluctant to use automatic tools to perform even the most common tasks of data reduction and data mining. The federation of heterogeneous large astronomical databases which is foreseen in the framework of the astrophysical virtual observatory and national virtual observatory projects, is, however, posing unprecedented data mining and visualization problems which will find a rather natural and user friendly answer in artificial intelligence tools based on NNs, fuzzy sets or genetic algorithms. This review is aimed to both astronomers (who often have little knowledge of the methodological background) and computer scientists (who often know little about potentially interesting applications), and therefore will be structured as follows: after giving a short introduction to the subject, we shall summarize the methodological background and focus our attention on some of the most interesting fields of application, namely: object extraction and classification, time series analysis, noise identification, and data mining. Most of the original work described in the paper has been performed in the framework of the AstroNeural collaboration (Napoli-Salerno).

  2. Neural relativity principle

    Science.gov (United States)

    Koulakov, Alexei

    Olfaction is the final frontier of our senses - the one that is still almost completely mysterious to us. Despite extensive genetic and perceptual data, and a strong push to solve the neural coding problem, fundamental questions about the sense of smell remain unresolved. Unlike vision and hearing, where relatively straightforward relationships between stimulus features and neural responses have been foundational to our understanding sensory processing, it has been difficult to quantify the properties of odorant molecules that lead to olfactory percepts. In a sense, we do not have olfactory analogs of ``red'', ``green'' and ``blue''. The seminal work of Linda Buck and Richard Axel identified a diverse family of about 1000 receptor molecules that serve as odorant sensors in the nose. However, the properties of smells that these receptors detect remain a mystery. I will review our current understanding of the molecular properties important to the olfactory system. I will also describe a theory that explains how odorant identity can be preserved despite substantial changes in the odorant concentration.

  3. Medical diagnosis using neural network

    CERN Document Server

    Kamruzzaman, S M; Siddiquee, Abu Bakar; Mazumder, Md Ehsanul Hoque

    2010-01-01

    This research is to search for alternatives to the resolution of complex medical diagnosis where human knowledge should be apprehended in a general fashion. Successful application examples show that human diagnostic capabilities are significantly worse than the neural diagnostic system. This paper describes a modified feedforward neural network constructive algorithm (MFNNCA), a new algorithm for medical diagnosis. The new constructive algorithm with backpropagation; offer an approach for the incremental construction of near-minimal neural network architectures for pattern classification. The algorithm starts with minimal number of hidden units in the single hidden layer; additional units are added to the hidden layer one at a time to improve the accuracy of the network and to get an optimal size of a neural network. The MFNNCA was tested on several benchmarking classification problems including the cancer, heart disease and diabetes. Experimental results show that the MFNNCA can produce optimal neural networ...

  4. Neural fields theory and applications

    CERN Document Server

    Graben, Peter; Potthast, Roland; Wright, James

    2014-01-01

    With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

  5. Neural Alterations in Acquired Age-Related Hearing Loss

    Directory of Open Access Journals (Sweden)

    Raksha Anand Mudar

    2016-06-01

    Full Text Available Hearing loss is one of the most prevalent chronic health conditions in older adults. Growing evidence suggests that hearing loss is associated with reduced cognitive functioning and incident dementia. In this mini-review, we briefly examine literature on anatomical and functional alterations in the brains of adults with acquired age-associated hearing loss, which may underlie the cognitive consequences observed in this population, focusing on studies that have used structural and functional magnetic resonance imaging, diffusion tensor imaging, and event-related electroencephalography. We discuss structural and functional alterations observed in the temporal and frontal cortices and the limbic system. These neural alterations are discussed in the context of common cause, information-degradation, and sensory-deprivation hypotheses, and we suggest possible rehabilitation strategies. Although we are beginning to learn more about changes in neural architecture and functionality related to age-associated hearing loss, much work remains to be done. Understanding the neural alterations will provide objective markers for early identification of neural consequences of age-associated hearing loss and for evaluating benefits of intervention approaches.

  6. Sub-meninges implantation reduces immune response to neural implants.

    Science.gov (United States)

    Markwardt, Neil T; Stokol, Jodi; Rennaker, Robert L

    2013-04-15

    Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability.

  7. Chronic Kidney Diseases

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Chronic Kidney Diseases KidsHealth > For Kids > Chronic Kidney Diseases Print ... re talking about your kidneys. What Are the Kidneys? Your kidneys are tucked under your lower ribs ...

  8. Diet - chronic kidney disease

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002442.htm Diet - chronic kidney disease To use the sharing features on this page, ... make changes to your diet when you have chronic kidney disease. These changes may include limiting fluids, eating a ...

  9. Chronic granulomatous disease

    Science.gov (United States)

    CGD; Fatal granulomatosis of childhood; Chronic granulomatous disease of childhood; Progressive septic granulomatosis ... In chronic granulomatous disease (CGD), immune system cells called phagocytes are unable to kill some types of bacteria and ...

  10. Chronic mucus hypersecretion

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli; von Linstow, Marie-Louise; Nepper-Christensen, Steen;

    2005-01-01

    To investigate if chronic mucus hypersecretion (CMH) can be used as a marker of asthma in young adults.......To investigate if chronic mucus hypersecretion (CMH) can be used as a marker of asthma in young adults....

  11. Chronic tophaceous gout

    Directory of Open Access Journals (Sweden)

    Thappa D

    1993-01-01

    Full Text Available A rare case of chronic tophaceous gout, in a 27-year-old female on diuretics for chronic congestive cardiac failure with characteristic histopathological and radiological changes is reported.

  12. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... maintaining good health. Can chronic pancreatitis give my child cancer? If your child has chronic pancreatitis, he or she will be at an increased risk of developing pancreatic cancer compared to the general population. The degree of ...

  13. People Experiencing Chronic Homelessness

    Science.gov (United States)

    ... Goals Ending Chronic Homelessness Share This: Ending Chronic Homelessness Last updated on January 19, 2017 We can ... the USICH newsletter. We know how to end homelessness. Let's do it, together. Sign up for our ...

  14. Positive emotions and brain reward circuits in chronic pain.

    Science.gov (United States)

    Navratilova, Edita; Morimura, Kozo; Xie, Jennifer Y; Atcherley, Christopher W; Ossipov, Michael H; Porreca, Frank

    2016-06-01

    Chronic pain is an important public health problem that negatively impacts the quality of life of affected individuals and exacts enormous socioeconomic costs. Chronic pain is often accompanied by comorbid emotional disorders including anxiety, depression, and possibly anhedonia. The neural circuits underlying the intersection of pain and pleasure are not well understood. We summarize recent human and animal investigations and demonstrate that aversive aspects of pain are encoded in brain regions overlapping with areas processing reward and motivation. We highlight findings revealing anatomical and functional alterations of reward/motivation circuits in chronic pain. Finally, we review supporting evidence for the concept that pain relief is rewarding and activates brain reward/motivation circuits. Adaptations in brain reward circuits may be fundamental to the pathology of chronic pain. Knowledge of brain reward processing in the context of pain could lead to the development of new therapeutics for the treatment of emotional aspects of pain and comorbid conditions.

  15. A Miniaturized System for Neural Signal Acquiring and Processing

    Institute of Scientific and Technical Information of China (English)

    WANG Min; GAO Guang-hong; XIANG Dong-sheng; CAO Mao-yong; JIA Ai-bin; DING Lei; KONG Hui-min

    2008-01-01

    To collect neural activity data from awake, behaving freely animals, we develop miniaturized implantable recording system by the modern chip:Programmable System on Chip(PSoC) and through chronic electrodes in the cortex. With PSoC family member CY8C29466,the system completed operational and instrument amplifiers, filters, timers, AD convertors, and serial communication, etc. The signal processing was dealt with virtual instrument technology. All of these factors can significantly affect the price and development cycle of the project. The result showed that the system was able to record and analyze neural extrocellular discharge generated by neurons continuously for a week or more. This is very useful for the interdisciplinary research of neuroscience and information engineering technique.The circuits and architecture of the devices can be adapted for neurobiology and research with other small animals.

  16. Learning not to fear: neural correlates of learned safety.

    Science.gov (United States)

    Kong, Eryan; Monje, Francisco J; Hirsch, Joy; Pollak, Daniela D

    2014-02-01

    The ability to recognize and properly respond to instances of protection from impending danger is critical for preventing chronic stress and anxiety-central symptoms of anxiety and affective disorders afflicting large populations of people. Learned safety encompasses learning processes, which lead to the identification of episodes of security and regulation of fear responses. On the basis of insights into the neural circuitry and molecular mechanisms involved in learned safety in mice and humans, we describe learned safety as a tool for understanding neural mechanisms involved in the pathomechanisms of specific affective disorders. This review summarizes our current knowledge on the neurobiological underpinnings of learned safety and discusses potential applications in basic and translational neurosciences.

  17. Glaucoma detection based on deep convolutional neural network.

    Science.gov (United States)

    Xiangyu Chen; Yanwu Xu; Damon Wing Kee Wong; Tien Yin Wong; Jiang Liu

    2015-08-01

    Glaucoma is a chronic and irreversible eye disease, which leads to deterioration in vision and quality of life. In this paper, we develop a deep learning (DL) architecture with convolutional neural network for automated glaucoma diagnosis. Deep learning systems, such as convolutional neural networks (CNNs), can infer a hierarchical representation of images to discriminate between glaucoma and non-glaucoma patterns for diagnostic decisions. The proposed DL architecture contains six learned layers: four convolutional layers and two fully-connected layers. Dropout and data augmentation strategies are adopted to further boost the performance of glaucoma diagnosis. Extensive experiments are performed on the ORIGA and SCES datasets. The results show area under curve (AUC) of the receiver operating characteristic curve in glaucoma detection at 0.831 and 0.887 in the two databases, much better than state-of-the-art algorithms. The method could be used for glaucoma detection.

  18. Neural correlates of consciousness.

    Science.gov (United States)

    Negrao, B L; Viljoen, M

    2009-11-01

    A basic understanding of consciousness and its neural correlates is of major importance for all clinicians, especially those involved with patients with altered states of consciousness. In this paper it is shown that consciousness is dependent on the brainstem and thalamus for arousal; that basic cognition is supported by recurrent electrical activity between the cortex and the thalamus at gamma band frequencies; aand that some kind of working memory must, at least fleetingly, be present for awareness to occur. The problem of cognitive binding and the role of attention are briefly addressed and it shown that consciousness depends on a multitude of subconscious processes. Although these processes do not represent consciousness, consciousness cannot exist without them.

  19. Neural Darwinism and consciousness.

    Science.gov (United States)

    Seth, Anil K; Baars, Bernard J

    2005-03-01

    Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the 'dynamic core'). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.

  20. Artificial Neural Network Analysis System

    Science.gov (United States)

    2007-11-02

    Contract No. DASG60-00-M-0201 Purchase request no.: Foot in the Door-01 Title Name: Artificial Neural Network Analysis System Company: Atlantic... Artificial Neural Network Analysis System 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Powell, Bruce C 5d. PROJECT NUMBER 5e. TASK NUMBER...34) 27-02-2001 Report Type N/A Dates Covered (from... to) ("DD MON YYYY") 28-10-2000 27-02-2001 Title and Subtitle Artificial Neural Network Analysis

  1. Cooperating attackers in neural cryptography.

    Science.gov (United States)

    Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  2. Approaching chronic sinusitis.

    Science.gov (United States)

    Sarber, Kathleen M; Dion, Gregory Robert; Weitzel, Erik K; McMains, Kevin C

    2013-11-01

    Chronic sinusitis is a common disease that encompasses a number of syndromes that are characterized by sinonasal mucosal inflammation. Chronic sinusitis can be defined as two or more of the following symptoms lasting for more than 12 consecutive weeks: discolored rhinorrhea, postnasal drip, nasal obstruction, facial pressure or pain, or decreased sense of smell. Chronic sinusitis is further classified as chronic sinusitis with polyposis, chronic sinusitis without polyposis, or allergic fungal sinusitis using physical examination, and histologic and radiographic findings. Treatment methods for chronic sinusitis are based upon categorization of the disease and include oral and inhaled corticosteroids, nasal saline irrigations, and antibiotics in selected patients. Understanding the various forms of chronic sinusitis and managing and ruling out comorbidities are key to successful management of this common disorder.

  3. Morphogenetic movements in the neural plate and neural tube: mouse.

    Science.gov (United States)

    Massarwa, R'ada; Ray, Heather J; Niswander, Lee

    2014-01-01

    The neural tube (NT), the embryonic precursor of the vertebrate brain and spinal cord, is generated by a complex and highly dynamic morphological process. In mammals, the initially flat neural plate bends and lifts bilaterally to generate the neural folds followed by fusion of the folds at the midline during the process of neural tube closure (NTC). Failures in any step of this process can lead to neural tube defects (NTDs), a common class of birth defects that occur in approximately 1 in 1000 live births. These severe birth abnormalities include spina bifida, a failure of closure at the spinal level; craniorachischisis, a failure of NTC along the entire body axis; and exencephaly, a failure of the cranial neural folds to close which leads to degeneration of the exposed brain tissue termed anencephaly. The mouse embryo presents excellent opportunities to explore the genetic basis of NTC in mammals; however, its in utero development has also presented great challenges in generating a deeper understanding of how gene function regulates the cell and tissue behaviors that drive this highly dynamic process. Recent technological advances are now allowing researchers to address these questions through visualization of NTC dynamics in the mouse embryo in real time, thus offering new insights into the morphogenesis of mammalian NTC.

  4. Chronic alcohol alters rewarded behaviors and striatal plasticity

    OpenAIRE

    DePoy, Lauren; Daut, Rachel; Wright, Tara; Camp, Marguerite; Crowley, Nicole; Noronha, Bianca; Lovinger, David; Holmes, Andrew

    2014-01-01

    Chronic intermittent ethanol (CIE) alters neural functions and behaviors mediated by the dorsolateral striatum (DLS) and prefrontal cortex. Here, we examined the effects of prolonged (16-bout) CIE on DLS plasticity and DLS-mediated behaviors. Ex vivo electrophysiological recordings revealed loss in efficacy of DLS synaptically induced activation and absent long-term depression after CIE. CIE increased two-bottle choice drinking and impaired Pavlovian-to-instrumental transfer but not discrimin...

  5. Modular, Hierarchical Learning By Artificial Neural Networks

    Science.gov (United States)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  6. A Study on Associative Neural Memories

    OpenAIRE

    B.D.C.N.Prasad; P. E. S. N. Krishna Prasad; Sagar Yeruva; P Sita Rama Murty

    2011-01-01

    Memory plays a major role in Artificial Neural Networks. Without memory, Neural Network can not be learned itself. One of the primary concepts of memory in neural networks is Associative neural memories. A survey has been made on associative neural memories such as Simple associative memories (SAM), Dynamic associative memories (DAM), Bidirectional Associative memories (BAM), Hopfield memories, Context Sensitive Auto-associative memories (CSAM) and so on. These memories can be applied in vari...

  7. Artificial intelligence: Deep neural reasoning

    Science.gov (United States)

    Jaeger, Herbert

    2016-10-01

    The human brain can solve highly abstract reasoning problems using a neural network that is entirely physical. The underlying mechanisms are only partially understood, but an artificial network provides valuable insight. See Article p.471

  8. Logic Mining Using Neural Networks

    CERN Document Server

    Sathasivam, Saratha

    2008-01-01

    Knowledge could be gained from experts, specialists in the area of interest, or it can be gained by induction from sets of data. Automatic induction of knowledge from data sets, usually stored in large databases, is called data mining. Data mining methods are important in the management of complex systems. There are many technologies available to data mining practitioners, including Artificial Neural Networks, Regression, and Decision Trees. Neural networks have been successfully applied in wide range of supervised and unsupervised learning applications. Neural network methods are not commonly used for data mining tasks, because they often produce incomprehensible models, and require long training times. One way in which the collective properties of a neural network may be used to implement a computational task is by way of the concept of energy minimization. The Hopfield network is well-known example of such an approach. The Hopfield network is useful as content addressable memory or an analog computer for s...

  9. Neural communication in posttraumatic growth.

    Science.gov (United States)

    Anders, Samantha L; Peterson, Carly K; James, Lisa M; Engdahl, Brian; Leuthold, Arthur C; Georgopoulos, Apostolos P

    2015-07-01

    Posttraumatic growth (PTG), or positive psychological changes following exposure to traumatic events, is commonly reported among trauma survivors. In the present study, we examined neural correlates of PTG in 106 veterans with PTSD and 193 veteran controls using task-free magnetoencephalography (MEG), diagnostic interviews and measures of PTG, and traumatic event exposure. Global synchronous neural interactions (SNIs) were significantly modulated downward with increasing PTG scores in controls (p = .005), but not in veterans with PTSD (p = .601). This effect was primarily characterized by negative slopes in local neural networks, was strongest in the medial prefrontal cortex, and was much stronger and more extensive in the control than the PTSD group. The present study complements previous research highlighting the role of neural adaptation in healthy functioning.

  10. Neural Networks in Control Applications

    DEFF Research Database (Denmark)

    Sørensen, O.

    examined, and it appears that considering 'normal' neural network models with, say, 500 samples, the problem of over-fitting is neglible, and therefore it is not taken into consideration afterwards. Numerous model types, often met in control applications, are implemented as neural network models....... - Control concepts including parameter estimation - Control concepts including inverse modelling - Control concepts including optimal control For each of the three groups, different control concepts and specific training methods are detailed described.Further, all control concepts are tested on the same......The intention of this report is to make a systematic examination of the possibilities of applying neural networks in those technical areas, which are familiar to a control engineer. In other words, the potential of neural networks in control applications is given higher priority than a detailed...

  11. Complex-Valued Neural Networks

    CERN Document Server

    Hirose, Akira

    2012-01-01

    This book is the second enlarged and revised edition of the first successful monograph on complex-valued neural networks (CVNNs) published in 2006, which lends itself to graduate and undergraduate courses in electrical engineering, informatics, control engineering, mechanics, robotics, bioengineering, and other relevant fields. In the second edition the recent trends in CVNNs research are included, resulting in e.g. almost a doubled number of references. The parametron invented in 1954 is also referred to with discussion on analogy and disparity. Also various additional arguments on the advantages of the complex-valued neural networks enhancing the difference to real-valued neural networks are given in various sections. The book is useful for those beginning their studies, for instance, in adaptive signal processing for highly functional sensing and imaging, control in unknown and changing environment, robotics inspired by human neural systems, and brain-like information processing, as well as interdisciplina...

  12. Neural correlates of consciousness reconsidered.

    Science.gov (United States)

    Neisser, Joseph

    2012-06-01

    It is widely accepted among philosophers that neuroscientists are conducting a search for the neural correlates of consciousness, or NCC. Chalmers (2000) conceptualized this research program as the attempt to correlate the contents of conscious experience with the contents of representations in specific neural populations. A notable claim on behalf of this interpretation is that the neutral language of "correlates" frees us from philosophical disputes over the mind/body relation, allowing the science to move independently. But the experimental paradigms and explanatory canons of neuroscience are not neutral about the mechanical relation between consciousness and the brain. I argue that NCC research is best characterized as an attempt to locate a causally relevant neural mechanism and not as an effort to identify a discrete neural representation, the content of which correlates with some actual experience. It might be said that the first C in "NCC" should stand for "causes" rather than "correlates."

  13. Neural components of altruistic punishment

    Directory of Open Access Journals (Sweden)

    Emily eDu

    2015-02-01

    Full Text Available Altruistic punishment, which occurs when an individual incurs a cost to punish in response to unfairness or a norm violation, may play a role in perpetuating cooperation. The neural correlates underlying costly punishment have only recently begun to be explored. Here we review the current state of research on the neural basis of altruism from the perspectives of costly punishment, emphasizing the importance of characterizing elementary neural processes underlying a decision to punish. In particular, we emphasize three cognitive processes that contribute to the decision to altruistically punish in most scenarios: inequity aversion, cost-benefit calculation, and social reference frame to distinguish self from others. Overall, we argue for the importance of understanding the neural correlates of altruistic punishment with respect to the core computations necessary to achieve a decision to punish.

  14. Serotonin, neural markers, and memory

    OpenAIRE

    Alfredo eMeneses

    2015-01-01

    Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The i...

  15. What are artificial neural networks?

    DEFF Research Database (Denmark)

    Krogh, Anders

    2008-01-01

    Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb......Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb...

  16. Neural Network Communications Signal Processing

    Science.gov (United States)

    1994-08-01

    Technical Information Report for the Neural Network Communications Signal Processing Program, CDRL A003, 31 March 1993. Software Development Plan for...track changing jamming conditions to provide the decoder with the best log- likelihood ratio metrics at a given time. As part of our development plan we...Artificial Neural Networks (ICANN-91) Volume 2, June 24-28, 1991, pp. 1677-1680. Kohonen, Teuvo, Raivio, Kimmo, Simula, Oli, Venta , 011i, Henriksson

  17. Flexibility of neural stem cells

    Directory of Open Access Journals (Sweden)

    Eumorphia eRemboutsika

    2011-04-01

    Full Text Available Embryonic cortical neural stem cells are self-renewing progenitors that can differentiate into neurons and glia. We generated neurospheres from the developing cerebral cortex using a mouse genetic model that allows for lineage selection and found that the self-renewing neural stem cells are restricted to Sox2 expressing cells. Under normal conditions, embryonic cortical neurospheres are heterogeneous with regard to Sox2 expression and contain astrocytes, neural stem cells and neural progenitor cells sufficiently plastic to give rise to neural crest cells when transplanted into the hindbrain of E1.5 chick and E8 mouse embryos. However, when neurospheres are maintained under lineage selection, such that all cells express Sox2, neural stem cells maintain their Pax6+ cortical radial glia identity and exhibit a more restricted fate in vitro and after transplantation. These data demonstrate that Sox2 preserves the cortical identity and regulates the plasticity of self-renewing Pax6+ radial glia cells.

  18. Activation of endogenous neural stem cells for multiple sclerosis therapy

    Directory of Open Access Journals (Sweden)

    Iliana eMichailidou

    2015-01-01

    Full Text Available Multiple sclerosis (MS is a chronic inflammatory disorder of the central nervous system, leading to severe neurological deficits. Current MS treatment regimens, consist of immunomodulatory agents aiming to reduce the rate of relapses. However, these agents are usually insufficient to treat chronic neurological disability.A promising perspective for future therapy of MS is the regeneration of lesions with replacement of the damaged oligodendrocytes or neurons. Therapies targeting to the enhancement of endogenous remyelination, aim to promote the activation of either the parenchymal oligodendrocyte progenitor cells or the subventricular zone-derived neural stem cells (NSCs. Less studied but highly potent, is the strategy of neuronal regeneration with endogenous NSCs that although being linked to numerous limitations, is anticipated to ameliorate cognitive disability in MS. Focusing on the forebrain, this review highlights the role of NSCs in the regeneration of MS lesions.

  19. Biofilms in chronic wounds.

    Science.gov (United States)

    James, Garth A; Swogger, Ellen; Wolcott, Randall; Pulcini, Elinor deLancey; Secor, Patrick; Sestrich, Jennifer; Costerton, John W; Stewart, Philip S

    2008-01-01

    Chronic wounds including diabetic foot ulcers, pressure ulcers, and venous leg ulcers are a worldwide health problem. It has been speculated that bacteria colonizing chronic wounds exist as highly persistent biofilm communities. This research examined chronic and acute wounds for biofilms and characterized microorganisms inhabiting these wounds. Chronic wound specimens were obtained from 77 subjects and acute wound specimens were obtained from 16 subjects. Culture data were collected using standard clinical techniques. Light and scanning electron microscopy techniques were used to analyze 50 of the chronic wound specimens and the 16 acute wound specimens. Molecular analyses were performed on the remaining 27 chronic wound specimens using denaturing gradient gel electrophoresis and sequence analysis. Of the 50 chronic wound specimens evaluated by microscopy, 30 were characterized as containing biofilm (60%), whereas only one of the 16 acute wound specimens was characterized as containing biofilm (6%). This was a statistically significant difference (p<0.001). Molecular analyses of chronic wound specimens revealed diverse polymicrobial communities and the presence of bacteria, including strictly anaerobic bacteria, not revealed by culture. Bacterial biofilm prevalence in specimens from chronic wounds relative to acute wounds observed in this study provides evidence that biofilms may be abundant in chronic wounds.

  20. In Vitro Developmental Neurotoxicity Following Chronic Exposure to 50 Hz Extremely Low-Frequency Electromagnetic Fields in Primary Rat Cortical Cultures.

    Science.gov (United States)

    de Groot, Martje W G D M; van Kleef, Regina G D M; de Groot, Aart; Westerink, Remco H S

    2016-02-01

    Exposure to 50-60 Hz extremely low-frequency electromagnetic fields (ELF-EMFs) has increased considerably over the last decades. Several epidemiological studies suggested that ELF-EMF exposure is associated with adverse health effects, including neurotoxicity. However, these studies are debated as results are often contradictory and the possible underlying mechanisms are unknown. Since the developing nervous system is particularly vulnerable to insults, we investigate effects of chronic, developmental ELF-EMF exposure in vitro. Primary rat cortical neurons received 7 days developmental exposure to 50 Hz block-pulsed ELF-EMF (0-1000 μT) to assess effects on cell viability (Alamar Blue/CFDA assay), calcium homeostasis (single cell fluorescence microscopy), neurite outgrowth (β(III)-Tubulin immunofluorescent staining), and spontaneous neuronal activity (multi-electrode arrays). Our data demonstrate that cell viability is not affected by developmental ELF-EMF (0-1000 μT) exposure. Depolarization- and glutamate-evoked increases in intracellular calcium concentration ([Ca(2+)]i) are slightly increased at 1 μT, whereas both basal and stimulation-evoked [Ca(2+)]i show a modest inhibition at 1000 μT. Subsequent morphological analysis indicated that neurite length is unaffected up to 100 μT, but increased at 1000 μT. However, neuronal activity appeared largely unaltered following chronic ELF-EMF exposure up to 1000 μT. The effects of ELF-EMF exposure were small and largely restricted to the highest field strength (1000 μT), ie, 10 000 times above background exposure and well above current residential exposure limits. Our combined data therefore indicate that chronic ELF-EMF exposure has only limited (developmental) neurotoxic potential in vitro.

  1. Recurrent neural collective classification.

    Science.gov (United States)

    Monner, Derek D; Reggia, James A

    2013-12-01

    With the recent surge in availability of data sets containing not only individual attributes but also relationships, classification techniques that take advantage of predictive relationship information have gained in popularity. The most popular existing collective classification techniques have a number of limitations-some of them generate arbitrary and potentially lossy summaries of the relationship data, whereas others ignore directionality and strength of relationships. Popular existing techniques make use of only direct neighbor relationships when classifying a given entity, ignoring potentially useful information contained in expanded neighborhoods of radius greater than one. We present a new technique that we call recurrent neural collective classification (RNCC), which avoids arbitrary summarization, uses information about relationship directionality and strength, and through recursive encoding, learns to leverage larger relational neighborhoods around each entity. Experiments with synthetic data sets show that RNCC can make effective use of relationship data for both direct and expanded neighborhoods. Further experiments demonstrate that our technique outperforms previously published results of several collective classification methods on a number of real-world data sets.

  2. Reversible neural stem cell niche dysfunction in a model of multiple sclerosis

    DEFF Research Database (Denmark)

    Rasmussen, Stine; Imitola, Jaime; Ayuso-Sacido, Angel;

    2011-01-01

    OBJECTIVE: The subventricular zone (SVZ) of the brain constitutes a niche for neural stem and progenitor cells that can initiate repair after central nervous system (CNS) injury. In a relapsing-remitting model of experimental autoimmune encephalomyelitis (EAE), the neural stem cells (NSCs) become...... with minocycline, an inhibitor of microglia activation, increases stem cell proliferation in both naive and EAE animals. Minocycline treatment decreases cortical and periventricular pathology in the chronic phase of EAE, improving the proliferation of Sox2 stem cells and NG2 oligodendrocyte precursors cells...

  3. Fractional Hopfield Neural Networks: Fractional Dynamic Associative Recurrent Neural Networks.

    Science.gov (United States)

    Pu, Yi-Fei; Yi, Zhang; Zhou, Ji-Liu

    2016-07-14

    This paper mainly discusses a novel conceptual framework: fractional Hopfield neural networks (FHNN). As is commonly known, fractional calculus has been incorporated into artificial neural networks, mainly because of its long-term memory and nonlocality. Some researchers have made interesting attempts at fractional neural networks and gained competitive advantages over integer-order neural networks. Therefore, it is naturally makes one ponder how to generalize the first-order Hopfield neural networks to the fractional-order ones, and how to implement FHNN by means of fractional calculus. We propose to introduce a novel mathematical method: fractional calculus to implement FHNN. First, we implement fractor in the form of an analog circuit. Second, we implement FHNN by utilizing fractor and the fractional steepest descent approach, construct its Lyapunov function, and further analyze its attractors. Third, we perform experiments to analyze the stability and convergence of FHNN, and further discuss its applications to the defense against chip cloning attacks for anticounterfeiting. The main contribution of our work is to propose FHNN in the form of an analog circuit by utilizing a fractor and the fractional steepest descent approach, construct its Lyapunov function, prove its Lyapunov stability, analyze its attractors, and apply FHNN to the defense against chip cloning attacks for anticounterfeiting. A significant advantage of FHNN is that its attractors essentially relate to the neuron's fractional order. FHNN possesses the fractional-order-stability and fractional-order-sensitivity characteristics.

  4. The holographic neural network: Performance comparison with other neural networks

    Science.gov (United States)

    Klepko, Robert

    1991-10-01

    The artificial neural network shows promise for use in recognition of high resolution radar images of ships. The holographic neural network (HNN) promises a very large data storage capacity and excellent generalization capability, both of which can be achieved with only a few learning trials, unlike most neural networks which require on the order of thousands of learning trials. The HNN is specially designed for pattern association storage, and mathematically realizes the storage and retrieval mechanisms of holograms. The pattern recognition capability of the HNN was studied, and its performance was compared with five other commonly used neural networks: the Adaline, Hamming, bidirectional associative memory, recirculation, and back propagation networks. The patterns used for testing represented artificial high resolution radar images of ships, and appear as a two dimensional topology of peaks with various amplitudes. The performance comparisons showed that the HNN does not perform as well as the other neural networks when using the same test data. However, modification of the data to make it appear more Gaussian distributed, improved the performance of the network. The HNN performs best if the data is completely Gaussian distributed.

  5. Fibromyalgia, chronic fatigue syndrome, and myofascial pain.

    Science.gov (United States)

    Bennett, R

    1998-03-01

    Epidemiologic studies continue to provide evidence that fibromyalgia is part of a spectrum of chronic widespread pain. The prevalence of chronic widespread pain is several times higher than fibromyalgia as defined by the 1990 American College of Rheumatology guidelines. There is now compelling evidence of a familial clustering of fibromyalgia cases in female sufferers; whether this clustering results from nature or nature remains to be elucidated. A wide spectrum of fibromyalgia-associated symptomatology and syndromes continues to be described. During the past year the association with interstitial cystitis has been explored, and neurally mediated hypotension has been documented in both fibromyalgia and chronic fatigue syndrome. Abnormalities of the growth hormone-insulin-like growth factor-1 axis have been also documented in both fibromyalgia and chronic fatigue syndrome. The commonly reported but anecdotal association of fibromyalgia with whiplash-type neck trauma was validated in a report from Israel. However, unlike North America, 100% of Israeli patients with posttraumatic fibromyalgia returned to work. Basic research in fibromyalgia continues to pinpoint abnormal sensory processing as being integral to understanding fibromyalgia pain. Drugs such as ketamine, which block N-methyl-D-aspartate receptors (which are often upregulated in central pain states) were shown to benefit fibromyalgia pain in an experimental setting. The combination of fluoxetine and amitriptyline was reported to be more beneficial than either drug alone in patients with fibromyalgia. A high prevalence of autoantibodies to cytoskeletal and nuclear envelope proteins was found in chronic fatigue syndrome, and an increased prevalence of antipolymer antibodies was found in symptomatic silicone breast implant recipients who often have fibromyalgia.

  6. Chronic Inflammatory Polyneuropathy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-02-01

    Full Text Available Thirteen children with chronic inflammatory demyelinating polyneuropathy monitored between 1975 and 2005 are reported from Centre hospitalier universitaire Sainte-Justine, Montreal, Canada.

  7. Multigradient for Neural Networks for Equalizers

    Directory of Open Access Journals (Sweden)

    Chulhee Lee

    2003-06-01

    Full Text Available Recently, a new training algorithm, multigradient, has been published for neural networks and it is reported that the multigradient outperforms the backpropagation when neural networks are used as a classifier. When neural networks are used as an equalizer in communications, they can be viewed as a classifier. In this paper, we apply the multigradient algorithm to train the neural networks that are used as equalizers. Experiments show that the neural networks trained using the multigradient noticeably outperforms the neural networks trained by the backpropagation.

  8. Neural network regulation driven by autonomous neural firings

    Science.gov (United States)

    Cho, Myoung Won

    2016-07-01

    Biological neurons naturally fire spontaneously due to the existence of a noisy current. Such autonomous firings may provide a driving force for network formation because synaptic connections can be modified due to neural firings. Here, we study the effect of autonomous firings on network formation. For the temporally asymmetric Hebbian learning, bidirectional connections lose their balance easily and become unidirectional ones. Defining the difference between reciprocal connections as new variables, we could express the learning dynamics as if Ising model spins interact with each other in magnetism. We present a theoretical method to estimate the interaction between the new variables in a neural system. We apply the method to some network systems and find some tendencies of autonomous neural network regulation.

  9. The Pattern of Neural Elements in the Islets of Normal and Diseased Pancreas and in Isolated Islets

    Directory of Open Access Journals (Sweden)

    Parviz M Pour

    2011-07-01

    Full Text Available Context The association between islet cells and neural elements, the so-called “neuro-insular complex”, has been known for centuries. Objective We examined the expression of beta-III tubulin, in normal pancreases from organ donors, surgical specimens of chronic pancreatitis, surgical specimens of ductal type carcinoma, isolated and purified islets of a 57-year-old male and the pancreases of adult Syrian golden hamsters by immunohistochemistry using a monoclonal antibody to beta-tubulin. Results In the normal pancreas of humans and hamsters, beta-III tubulin was expressed in alpha- and beta-cells, but not in PP cells, neural fibers and gangliae. Occasionally, intra-and peri-insular neural elements were also found. In chronic pancreatitis and pancreatic cancer samples, the number of beta-cells and the immunoreactivity of the beta-III tubulin antibody in islet cells were decreased in most cases. In cultured human islets, devoid of neural elements, no correlation was found between the expression of beta-III tubulin and islet cell hormones. Conclusion Beta-III tubulin is only expressed in the islets derived from the dorsal pancreas and in neural elements. In chronic pancreatitis and pancreatic cancer swelling of intra- and peri-insular nerves occurs, possibly in response to the loss of beta-cells. The secretion of insulin and the expression of beta-tubulin seem to be regulated by nerves.

  10. Selective Manipulation of Neural Circuits.

    Science.gov (United States)

    Park, Hong Geun; Carmel, Jason B

    2016-04-01

    Unraveling the complex network of neural circuits that form the nervous system demands tools that can manipulate specific circuits. The recent evolution of genetic tools to target neural circuits allows an unprecedented precision in elucidating their function. Here we describe two general approaches for achieving circuit specificity. The first uses the genetic identity of a cell, such as a transcription factor unique to a circuit, to drive expression of a molecule that can manipulate cell function. The second uses the spatial connectivity of a circuit to achieve specificity: one genetic element is introduced at the origin of a circuit and the other at its termination. When the two genetic elements combine within a neuron, they can alter its function. These two general approaches can be combined to allow manipulation of neurons with a specific genetic identity by introducing a regulatory gene into the origin or termination of the circuit. We consider the advantages and disadvantages of both these general approaches with regard to specificity and efficacy of the manipulations. We also review the genetic techniques that allow gain- and loss-of-function within specific neural circuits. These approaches introduce light-sensitive channels (optogenetic) or drug sensitive channels (chemogenetic) into neurons that form specific circuits. We compare these tools with others developed for circuit-specific manipulation and describe the advantages of each. Finally, we discuss how these tools might be applied for identification of the neural circuits that mediate behavior and for repair of neural connections.

  11. Neural recording and modulation technologies

    Science.gov (United States)

    Chen, Ritchie; Canales, Andres; Anikeeva, Polina

    2017-01-01

    In the mammalian nervous system, billions of neurons connected by quadrillions of synapses exchange electrical, chemical and mechanical signals. Disruptions to this network manifest as neurological or psychiatric conditions. Despite decades of neuroscience research, our ability to treat or even to understand these conditions is limited by the capability of tools to probe the signalling complexity of the nervous system. Although orders of magnitude smaller and computationally faster than neurons, conventional substrate-bound electronics do not recapitulate the chemical and mechanical properties of neural tissue. This mismatch results in a foreign-body response and the encapsulation of devices by glial scars, suggesting that the design of an interface between the nervous system and a synthetic sensor requires additional materials innovation. Advances in genetic tools for manipulating neural activity have fuelled the demand for devices that are capable of simultaneously recording and controlling individual neurons at unprecedented scales. Recently, flexible organic electronics and bio- and nanomaterials have been developed for multifunctional and minimally invasive probes for long-term interaction with the nervous system. In this Review, we discuss the design lessons from the quarter-century-old field of neural engineering, highlight recent materials-driven progress in neural probes and look at emergent directions inspired by the principles of neural transduction.

  12. VLSI implementation of neural networks.

    Science.gov (United States)

    Wilamowski, B M; Binfet, J; Kaynak, M O

    2000-06-01

    Currently, fuzzy controllers are the most popular choice for hardware implementation of complex control surfaces because they are easy to design. Neural controllers are more complex and hard to train, but provide an outstanding control surface with much less error than that of a fuzzy controller. There are also some problems that have to be solved before the networks can be implemented on VLSI chips. First, an approximation function needs to be developed because CMOS neural networks have an activation function different than any function used in neural network software. Next, this function has to be used to train the network. Finally, the last problem for VLSI designers is the quantization effect caused by discrete values of the channel length (L) and width (W) of MOS transistor geometries. Two neural networks were designed in 1.5 microm technology. Using adequate approximation functions solved the problem of activation function. With this approach, trained networks were characterized by very small errors. Unfortunately, when the weights were quantized, errors were increased by an order of magnitude. However, even though the errors were enlarged, the results obtained from neural network hardware implementations were superior to the results obtained with fuzzy system approach.

  13. Neural probe design for reduced tissue encapsulation in CNS.

    Science.gov (United States)

    Seymour, John P; Kipke, Daryl R

    2007-09-01

    This study investigated relationships between a microscale neural probe's size and shape and its chronic reactive tissue response. Parylene-based probes were microfabricated with a thick shank (48 microm by 68 microm) and an integrated thin lateral platform (5 microm by 100 microm, either solid or one of three lattice sizes). Devices were implanted in rat cerebral cortex for 4 weeks before immunostaining for neurons, astrocytes, microglia, fibronectin, laminin, and neurofilament. While nonneuronal density (NND) generally increased and neuronal density decreased within 75 microm of a probe interface compared to unimplanted control regions, there were significant differential tissue responses within 25 microm of the platform's lateral edge compared to the shank. The NND in this region of the lateral edge was less than one-third of the corresponding region of the shank (129% and 425% increase, respectively). Moreover, neuronal density around the platform lateral edge was about one-third higher than at the shank (0.70 and 0.52 relative to control, respectively). Also, microglia reactivity and extracellular protein deposition was reduced at the lateral edge. There were no significant differences among platform designs. These results suggest that neural probe geometry is an important parameter for reducing chronic tissue encapsulation.

  14. Neural Correlate of Anterograde Amnesia in Wernicke-Korsakoff Syndrome.

    Science.gov (United States)

    Nahum, Louis; Pignat, Jean-Michel; Bouzerda-Wahlen, Aurélie; Gabriel, Damien; Liverani, Maria Chiara; Lazeyras, François; Ptak, Radek; Richiardi, Jonas; Haller, Sven; Thorens, Gabriel; Zullino, Daniele F; Guggisberg, Adrian G; Schnider, Armin

    2015-09-01

    The neural correlate of anterograde amnesia in Wernicke-Korsakoff syndrome (WKS) is still debated. While the capacity to learn new information has been associated with integrity of the medial temporal lobe (MTL), previous studies indicated that the WKS is associated with diencephalic lesions, mainly in the mammillary bodies and anterior or dorsomedial thalamic nuclei. The present study tested the hypothesis that amnesia in WKS is associated with a disrupted neural circuit between diencephalic and hippocampal structures. High-density evoked potentials were recorded in four severely amnesic patients with chronic WKS, in five patients with chronic alcoholism without WKS, and in ten age matched controls. Participants performed a continuous recognition task of pictures previously shown to induce a left medial temporal lobe dependent positive potential between 250 and 350 ms. In addition, the integrity of the fornix was assessed using diffusion tensor imaging (DTI). WKS, but not alcoholic patients without WKS, showed absence of the early, left MTL dependent positive potential following immediate picture repetitions. DTI indicated disruption of the fornix, which connects diencephalic and hippocampal structures. The findings support an interpretation of anterograde amnesia in WKS as a consequence of a disconnection between diencephalic and MTL structures with deficient contribution of the MTL to rapid consolidation.

  15. Psychoneuroendocrinological studies on chronic stress and depression.

    Science.gov (United States)

    Tafet, Gustavo E; Smolovich, Jaime

    2004-12-01

    The adaptive response to stress is characterized by activation of neural and neuroendocrine cascades mediated mainly by the noradrenergic/sympathetic and limbic-hypothalamic-pituitary-adrenal (HPA) systems, respectively. Chronic psychosocial stress has long been associated with the origin and development of depression, where increased levels of cortisol have been observed in both conditions. In this regard, increased levels of cortisol could be directly involved in the mood changes observed in depression, and direct connections between these and alterations of the serotonergic neurotransmission have been also proposed. Therefore, we investigated the potential link between alterations of the limbic-HPA system with the serotonergic hypothesis of depression at both the molecular and clinical levels. Our findings support the notion that chronic psychosocial stress may lead to depression in certain individuals depending on the psychobiological background and their particular psychological resources. Therefore, certain interventions aimed at normalization of the HPA system could potentially prevent the development of depression in chronically stressed subjects. This would be possible through either pharmacological interventions or psychotherapeutic strategies, such as cognitive therapy, aimed at improving resilience and controllability in stressful situations.

  16. Neural correlates of central inhibition during physical fatigue.

    Directory of Open Access Journals (Sweden)

    Masaaki Tanaka

    Full Text Available Central inhibition plays a pivotal role in determining physical performance during physical fatigue. Classical conditioning of central inhibition is believed to be associated with the pathophysiology of chronic fatigue. We tried to determine whether classical conditioning of central inhibition can really occur and to clarify the neural mechanisms of central inhibition related to classical conditioning during physical fatigue using magnetoencephalography (MEG. Eight right-handed volunteers participated in this study. We used metronome sounds as conditioned stimuli and maximum handgrip trials as unconditioned stimuli to cause central inhibition. Participants underwent MEG recording during imagery of maximum grips of the right hand guided by metronome sounds for 10 min. Thereafter, fatigue-inducing maximum handgrip trials were performed for 10 min; the metronome sounds were started 5 min after the beginning of the handgrip trials. The next day, neural activities during imagery of maximum grips of the right hand guided by metronome sounds were measured for 10 min. Levels of fatigue sensation and sympathetic nerve activity on the second day were significantly higher relative to those of the first day. Equivalent current dipoles (ECDs in the posterior cingulated cortex (PCC, with latencies of approximately 460 ms, were observed in all the participants on the second day, although ECDs were not identified in any of the participants on the first day. We demonstrated that classical conditioning of central inhibition can occur and that the PCC is involved in the neural substrates of central inhibition related to classical conditioning during physical fatigue.

  17. Neural mechanisms of mindfulness and meditation: Evidence from neuroimaging studies

    Institute of Scientific and Technical Information of China (English)

    William; R; Marchand

    2014-01-01

    Mindfulness is the dispassionate,moment-by-moment awareness of sensations,emotions and thoughts.Mindfulness-based interventions are being increasingly used for stress,psychological well being,coping with chronic illness as well as adjunctive treatments for psychiatric disorders.However,the neural mechanisms associated with mindfulness have not been well characterized.Recent functional and structural neuroimaging studies are beginning to provide insights into neural processes associated with the practice of mindfulness.A review of this literature revealed compelling evidence that mindfulness impacts the function of the medial cortex and associated default mode network as well as insula and amygdala.Additionally,mindfulness practice appears to effect lateral frontal regions and basal ganglia,at least in some cases.Structural imaging studies are consistent with these findings and also indicate changes in the hippocampus.While many questions remain unanswered,the current literature provides evidence of brain regions and networks relevant for understanding neural processes associated with mindfulness.

  18. Energy efficient neural stimulation: coupling circuit design and membrane biophysics.

    Directory of Open Access Journals (Sweden)

    Thomas J Foutz

    Full Text Available The delivery of therapeutic levels of electrical current to neural tissue is a well-established treatment for numerous indications such as Parkinson's disease and chronic pain. While the neuromodulation medical device industry has experienced steady clinical growth over the last two decades, much of the core technology underlying implanted pulse generators remain unchanged. In this study we propose some new methods for achieving increased energy-efficiency during neural stimulation. The first method exploits the biophysical features of excitable tissue through the use of a centered-triangular stimulation waveform. Neural activation with this waveform is achieved with a statistically significant reduction in energy compared to traditional rectangular waveforms. The second method demonstrates energy savings that could be achieved by advanced circuitry design. We show that the traditional practice of using a fixed compliance voltage for constant-current stimulation results in substantial energy loss. A portion of this energy can be recuperated by adjusting the compliance voltage to real-time requirements. Lastly, we demonstrate the potential impact of axon fiber diameter on defining the energy-optimal pulse-width for stimulation. When designing implantable pulse generators for energy efficiency, we propose that the future combination of a variable compliance system, a centered-triangular stimulus waveform, and an axon diameter specific stimulation pulse-width has great potential to reduce energy consumption and prolong battery life in neuromodulation devices.

  19. Effect of contrasting physical exercise interventions on rapid force capacity of chronically painful muscles

    DEFF Research Database (Denmark)

    Andersen, Lars L; Andersen, Jesper L; Suetta, Charlotte

    2009-01-01

    as neural and muscular adaptations in women with chronic neck muscle pain. A group of employed women (n = 42) with a clinical diagnosis of trapezius myalgia participated in a 10-wk randomized controlled trial; specific strength training of the neck/shoulder muscles, general fitness training performed as leg...

  20. Coping with Chronic Illness

    Science.gov (United States)

    Having a long-term, or chronic, illness can disrupt your life in many ways. You may often be tired and in pain. Your illness might affect your ... able to work, causing financial problems. For children, chronic illnesses can be frightening, because they may not ...

  1. Chronic Postoperative Roseomonas Endophthalmitis▿

    OpenAIRE

    Chen, Kuan-Jen; Lai, Chi-Chun; Kuo, Ya-Hui; WU, WEI-CHI; CHEN, TUN-LU

    2008-01-01

    We report one case with chronic postoperative endophthalmitis caused by Roseomonas species. Roseomonas spp. induced chronic endophthalmitis, which might result in misdiagnosis and delayed treatment and causes ocular damage and severe visual loss. This report is the first one related to a case with postoperative endophthalmitis secondary to Roseomonas infection.

  2. Chronic postoperative Roseomonas endophthalmitis.

    Science.gov (United States)

    Chen, Kuan-Jen; Lai, Chi-Chun; Kuo, Ya-Hui; Wu, Wei-Chi; Chen, Tun-Lu

    2009-01-01

    We report one case with chronic postoperative endophthalmitis caused by Roseomonas species. Roseomonas spp. induced chronic endophthalmitis, which might result in misdiagnosis and delayed treatment and causes ocular damage and severe visual loss. This report is the first one related to a case with postoperative endophthalmitis secondary to Roseomonas infection.

  3. Principles of neural information processing

    CERN Document Server

    Seelen, Werner v

    2016-01-01

    In this fundamental book the authors devise a framework that describes the working of the brain as a whole. It presents a comprehensive introduction to the principles of Neural Information Processing as well as recent and authoritative research. The books´ guiding principles are the main purpose of neural activity, namely, to organize behavior to ensure survival, as well as the understanding of the evolutionary genesis of the brain. Among the developed principles and strategies belong self-organization of neural systems, flexibility, the active interpretation of the world by means of construction and prediction as well as their embedding into the world, all of which form the framework of the presented description. Since, in brains, their partial self-organization, the lifelong adaptation and their use of various methods of processing incoming information are all interconnected, the authors have chosen not only neurobiology and evolution theory as a basis for the elaboration of such a framework, but also syst...

  4. Neural networks and statistical learning

    CERN Document Server

    Du, Ke-Lin

    2014-01-01

    Providing a broad but in-depth introduction to neural network and machine learning in a statistical framework, this book provides a single, comprehensive resource for study and further research. All the major popular neural network models and statistical learning approaches are covered with examples and exercises in every chapter to develop a practical working understanding of the content. Each of the twenty-five chapters includes state-of-the-art descriptions and important research results on the respective topics. The broad coverage includes the multilayer perceptron, the Hopfield network, associative memory models, clustering models and algorithms, the radial basis function network, recurrent neural networks, principal component analysis, nonnegative matrix factorization, independent component analysis, discriminant analysis, support vector machines, kernel methods, reinforcement learning, probabilistic and Bayesian networks, data fusion and ensemble learning, fuzzy sets and logic, neurofuzzy models, hardw...

  5. Neural plasticity lessons from disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Athena eDemertzi

    2011-02-01

    Full Text Available Communication and intentional behavior are supported by the brain’s integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state /unresponsive wakefulness syndrome, minimally conscious states. This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis and treatment, but also put forward scientific opportunities to study the brain’s plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions, suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation but also from a scientific-theoretical perspective (i.e., the brain’s plastic abilities and the pursuit of the neural correlate of consciousness.

  6. Neural plasticity lessons from disorders of consciousness.

    Science.gov (United States)

    Demertzi, Athena; Schnakers, Caroline; Soddu, Andrea; Bruno, Marie-Aurélie; Gosseries, Olivia; Vanhaudenhuyse, Audrey; Laureys, Steven

    2010-01-01

    Communication and intentional behavior are supported by the brain's integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state/unresponsive wakefulness syndrome, minimally conscious states). This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis, and treatment, but also put forward scientific opportunities to study the brain's plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions), suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation) but also from a scientific-theoretical perspective (i.e., the brain's plastic abilities and the pursuit of the neural correlate of consciousness).

  7. [Chronic pancreatitis, acute pancreatitis].

    Science.gov (United States)

    Mabuchi, T; Katada, N; Nishimura, D; Hoshino, H; Shimizu, F; Suzuki, R; Sano, H; Kato, K

    1998-11-01

    MRCP has been recognized as a safe and noninvasive diagnostic method. In the present study we evaluated the usefulness of MRCP in diagnosis of chronic and acute pancreatitis. Two-dimensional fast asymmetric spin-echo (FASE) MRCP was performed in 40 patients with chronic pancreatitis and 13 with acute pancreatitis. In 29 patients (72.5%) with chronic pancreatitis and 9 (66.7%) with acute pancreatitis, main pancreatic duct (MPD) was visualized entirely. MRCP could demonstrate the characteristic findings of chronic pancreatitis such as dilatation and irregularity of MPD in most cases. In acute pancreatitis, MRCP indicated that MPD was normal in diameter, but irregular in configuration compared with that of the control group. MRCP may facilitate the diagnosis of chronic and acute pancreatitis.

  8. The Chronic Responsibility

    DEFF Research Database (Denmark)

    Ravn, Iben M; Frederiksen, Kirsten; Beedholm, Kirsten

    2016-01-01

    This article reports on the results of a Fairclough-inspired critical discourse analysis aiming to clarify how chronically ill patients are presented in contemporary Danish chronic care policies. Drawing on Fairclough’s three-dimensional framework for analyzing discourse, and using Dean’s concepts...... of governmentality as an interpretative lens, we analyzed and explained six policies published by the Danish Health and Medicines Authority between 2005 and 2013. The analysis revealed that discourses within the policy vision of chronic care consider chronically ill patients’ active role, lifestyle, and health...... behavior to be the main factors influencing susceptibility to chronic diseases. We argue that this discursive construction naturalizes a division between people who can actively manage responsible self-care and those who cannot. Such discourses may serve the interests of those patients who are already...

  9. Chronic gastritis - an update.

    Science.gov (United States)

    Varbanova, Mariya; Frauenschläger, Katrin; Malfertheiner, Peter

    2014-12-01

    Helicobacter pylori is the main aetiologic factor for chronic gastritis worldwide. The degree of inflammation and the evolution of this form of chronic gastritis can vary largely depending on bacterial virulence factors, host susceptibility factors and environmental conditions. Autoimmune gastritis is another cause of chronic inflammation in the stomach, which can occur in all age groups. This disease presents typically with vitamin B12 deficiency and pernicious anaemia. The presence of anti-parietal cell antibodies is highly specific for the diagnosis. The role of H. pylori as a trigger for autoimmune gastritis remains uncertain. Other rare conditions for chronic gastritis are chronic inflammatory conditions such as Crohn's disease or on the background of lymphocytic or collagenous gastroenteropathies.

  10. Neural substrates of semantic memory.

    Science.gov (United States)

    Hart, John; Anand, Raksha; Zoccoli, Sandra; Maguire, Mandy; Gamino, Jacque; Tillman, Gail; King, Richard; Kraut, Michael A

    2007-09-01

    Semantic memory is described as the storage of knowledge, concepts, and information that is common and relatively consistent across individuals (e.g., memory of what is a cup). These memories are stored in multiple sensorimotor modalities and cognitive systems throughout the brain (e.g., how a cup is held and manipulated, the texture of a cup's surface, its shape, its function, that is related to beverages such as coffee, and so on). Our ability to engage in purposeful interactions with our environment is dependent on the ability to understand the meaning and significance of the objects and actions around us that are stored in semantic memory. Theories of the neural basis of the semantic memory of objects have produced sophisticated models that have incorporated to varying degrees the results of cognitive and neural investigations. The models are grouped into those that are (1) cognitive models, where the neural data are used to reveal dissociations in semantic memory after a brain lesion occurs; (2) models that incorporate both cognitive and neuroanatomical information; and (3) models that use cognitive, neuroanatomic, and neurophysiological data. This review highlights the advances and issues that have emerged from these models and points to future directions that provide opportunities to extend these models. The models of object memory generally describe how category and/or feature representations encode for object memory, and the semantic operations engaged in object processing. The incorporation of data derived from multiple modalities of investigation can lead to detailed neural specifications of semantic memory organization. The addition of neurophysiological data can potentially provide further elaboration of models to include semantic neural mechanisms. Future directions should incorporate available and newly developed techniques to better inform the neural underpinning of semantic memory models.

  11. Chronic granulomatous disease associated with chronic glomerulonephritis

    DEFF Research Database (Denmark)

    Frifelt, J J; Schønheyder, Henrik Carl; Valerius, Niels Henrik

    1985-01-01

    A boy with chronic granulomatous disease (CGD) developed glomerulonephritis at the age of 12 years. The glomerulonephritis progressed to terminal uraemia at age 15 when maintenance haemodialysis was started. The clinical course was complicated by pulmonary aspergillosis and Pseudomonas septicaemia...... from which he eventually died. The glomerulonephritis was of unknown origin, and a possible relationship between CGD and glomerulonephritis is discussed....

  12. Generalization performance of regularized neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1994-01-01

    Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...

  13. Opioid Use and Neural Tube Defects

    Science.gov (United States)

    ... CDC.gov . Articles Key Findings: Opioid Use and Neural Tube Defects Recommend on Facebook Tweet Share Compartir The ... relationship to having a pregnancy affected by a neural tube defect (NTD). Researchers from Boston University and CDC ...

  14. Neural overlap in processing music and speech.

    Science.gov (United States)

    Peretz, Isabelle; Vuvan, Dominique; Lagrois, Marie-Élaine; Armony, Jorge L

    2015-03-19

    Neural overlap in processing music and speech, as measured by the co-activation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing.

  15. Ocean wave forecasting using recurrent neural networks

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Prabaharan, N.

    , merchant vessel routing, nearshore construction, etc. more efficiently and safely. This paper describes an artificial neural network, namely recurrent neural network with rprop update algorithm and is applied for wave forecasting. Measured ocean waves off...

  16. Application of neural networks in coastal engineering

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    the neural network attractive. A neural network is an information processing system modeled on the structure of the dynamic process. It can solve the complex/nonlinear problems quickly once trained by operating on problems using an interconnected number...

  17. Plant Growth Models Using Artificial Neural Networks

    Science.gov (United States)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  18. What Is Chronic Myeloid Leukemia?

    Science.gov (United States)

    ... Chronic Myeloid Leukemia (CML) About Chronic Myeloid Leukemia What Is Chronic Myeloid Leukemia? Cancer starts when cells ... their treatment is the same as for adults. What is leukemia? Leukemia is a cancer that starts ...

  19. What Is Chronic Lymphocytic Leukemia?

    Science.gov (United States)

    ... Chronic Lymphocytic Leukemia (CLL) About Chronic Lymphocytic Leukemia What Is Chronic Lymphocytic Leukemia? Cancer starts when cells ... body, including the lymph nodes, liver, and spleen. What is leukemia? Leukemia is a cancer that starts ...

  20. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  1. Visual Grouping by Neural Oscillators

    CERN Document Server

    Yu, Guoshen

    2008-01-01

    Distributed synchronization is known to occur at several scales in the brain, and has been suggested as playing a key functional role in perceptual grouping. State-of-the-art visual grouping algorithms, however, seem to give comparatively little attention to neural synchronization analogies. Based on the framework of concurrent synchronization of dynamic systems, simple networks of neural oscillators coupled with diffusive connections are proposed to solve visual grouping problems. Multi-layer algorithms and feedback mechanisms are also studied. The same algorithm is shown to achieve promising results on several classical visual grouping problems, including point clustering, contour integration and image segmentation.

  2. Quantum computing in neural networks

    CERN Document Server

    Gralewicz, P

    2004-01-01

    According to the statistical interpretation of quantum theory, quantum computers form a distinguished class of probabilistic machines (PMs) by encoding n qubits in 2n pbits. This raises the possibility of a large-scale quantum computing using PMs, especially with neural networks which have the innate capability for probabilistic information processing. Restricting ourselves to a particular model, we construct and numerically examine the performance of neural circuits implementing universal quantum gates. A discussion on the physiological plausibility of proposed coding scheme is also provided.

  3. Mechanism of Chronic Pain in Rodent Brain Imaging

    Science.gov (United States)

    Chang, Pei-Ching

    Chronic pain is a significant health problem that greatly impacts the quality of life of individuals and imparts high costs to society. Despite intense research effort in understanding of the mechanism of pain, chronic pain remains a clinical problem that has few effective therapies. The advent of human brain imaging research in recent years has changed the way that chronic pain is viewed. To further extend the use of human brain imaging techniques for better therapies, the adoption of imaging technique onto the animal pain models is essential, in which underlying brain mechanisms can be systematically studied using various combination of imaging and invasive techniques. The general goal of this thesis is to addresses how brain develops and maintains chronic pain in an animal model using fMRI. We demonstrate that nucleus accumbens, the central component of mesolimbic circuitry, is essential in development of chronic pain. To advance our imaging technique, we develop an innovative methodology to carry out fMRI in awake, conscious rat. Using this cutting-edge technique, we show that allodynia is assoicated with shift brain response toward neural circuits associated nucleus accumbens and prefrontal cortex that regulate affective and cognitive component of pain. Taken together, this thesis provides a deeper understanding of how brain mediates pain. It builds on the existing body of knowledge through maximizing the depth of insight into brain imaging of chronic pain.

  4. Building a Chaotic Proved Neural Network

    CERN Document Server

    Bahi, Jacques M; Salomon, Michel

    2011-01-01

    Chaotic neural networks have received a great deal of attention these last years. In this paper we establish a precise correspondence between the so-called chaotic iterations and a particular class of artificial neural networks: global recurrent multi-layer perceptrons. We show formally that it is possible to make these iterations behave chaotically, as defined by Devaney, and thus we obtain the first neural networks proven chaotic. Several neural networks with different architectures are trained to exhibit a chaotical behavior.

  5. MEMBRAIN NEURAL NETWORK FOR VISUAL PATTERN RECOGNITION

    Directory of Open Access Journals (Sweden)

    Artur Popko

    2013-06-01

    Full Text Available Recognition of visual patterns is one of significant applications of Artificial Neural Networks, which partially emulate human thinking in the domain of artificial intelligence. In the paper, a simplified neural approach to recognition of visual patterns is portrayed and discussed. This paper is dedicated for investigators in visual patterns recognition, Artificial Neural Networking and related disciplines. The document describes also MemBrain application environment as a powerful and easy to use neural networks’ editor and simulator supporting ANN.

  6. Meta-Learning Evolutionary Artificial Neural Networks

    OpenAIRE

    Abraham, Ajith

    2004-01-01

    In this paper, we present MLEANN (Meta-Learning Evolutionary Artificial Neural Network), an automatic computational framework for the adaptive optimization of artificial neural networks wherein the neural network architecture, activation function, connection weights; learning algorithm and its parameters are adapted according to the problem. We explored the performance of MLEANN and conventionally designed artificial neural networks for function approximation problems. To evaluate the compara...

  7. Simplified LQG Control with Neural Networks

    DEFF Research Database (Denmark)

    Sørensen, O.

    1997-01-01

    A new neural network application for non-linear state control is described. One neural network is modelled to form a Kalmann predictor and trained to act as an optimal state observer for a non-linear process. Another neural network is modelled to form a state controller and trained to produce...

  8. Analysis of Neural Networks through Base Functions

    NARCIS (Netherlands)

    Zwaag, van der B.J.; Slump, C.H.; Spaanenburg, L.

    2002-01-01

    Problem statement. Despite their success-story, neural networks have one major disadvantage compared to other techniques: the inability to explain comprehensively how a trained neural network reaches its output; neural networks are not only (incorrectly) seen as a "magic tool" but possibly even more

  9. Competition Based Neural Networks for Assignment Problems

    Institute of Scientific and Technical Information of China (English)

    李涛; LuyuanFang

    1991-01-01

    Competition based neural networks have been used to solve the generalized assignment problem and the quadratic assignment problem.Both problems are very difficult and are ε approximation complete.The neural network approach has yielded highly competitive performance and good performance for the quadratic assignment problem.These neural networks are guaranteed to produce feasible solutions.

  10. Classification using Bayesian neural nets

    NARCIS (Netherlands)

    J.C. Bioch (Cor); O. van der Meer; R. Potharst (Rob)

    1995-01-01

    textabstractRecently, Bayesian methods have been proposed for neural networks to solve regression and classification problems. These methods claim to overcome some difficulties encountered in the standard approach such as overfitting. However, an implementation of the full Bayesian approach to neura

  11. Serotonin, neural markers, and memory.

    Science.gov (United States)

    Meneses, Alfredo

    2015-01-01

    Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The interactions among behavioral tasks, control groups and molecular changes and/or pharmacological effects are mentioned. Neurotransmitter receptors and signaling pathways, during normal and abnormally functioning memory with an emphasis on the behavioral aspects of memory are revised. With focus on serotonin, since as it is a well characterized neurotransmitter, with multiple pharmacological tools, and well characterized downstream signaling in mammals' species. 5-HT1A, 5-HT4, 5-HT5, 5-HT6, and 5-HT7 receptors as well as SERT (serotonin transporter) seem to be useful neural markers and/or therapeutic targets. Certainly, if the mentioned evidence is replicated, then the translatability from preclinical and clinical studies to neural changes might be confirmed. Hypothesis and theories might provide appropriate limits and perspectives of evidence.

  12. Neural Circuits on a Chip

    Directory of Open Access Journals (Sweden)

    Md. Fayad Hasan

    2016-09-01

    Full Text Available Neural circuits are responsible for the brain’s ability to process and store information. Reductionist approaches to understanding the brain include isolation of individual neurons for detailed characterization. When maintained in vitro for several days or weeks, dissociated neurons self-assemble into randomly connected networks that produce synchronized activity and are capable of learning. This review focuses on efforts to control neuronal connectivity in vitro and construct living neural circuits of increasing complexity and precision. Microfabrication-based methods have been developed to guide network self-assembly, accomplishing control over in vitro circuit size and connectivity. The ability to control neural connectivity and synchronized activity led to the implementation of logic functions using living neurons. Techniques to construct and control three-dimensional circuits have also been established. Advances in multiple electrode arrays as well as genetically encoded, optical activity sensors and transducers enabled highly specific interfaces to circuits composed of thousands of neurons. Further advances in on-chip neural circuits may lead to better understanding of the brain.

  13. Nanomaterial-enabled neural stimulation

    Directory of Open Access Journals (Sweden)

    Yongchen eWang

    2016-03-01

    Full Text Available Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  14. Nanomaterial-Enabled Neural Stimulation.

    Science.gov (United States)

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  15. Aphasia Classification Using Neural Networks

    DEFF Research Database (Denmark)

    Axer, H.; Jantzen, Jan; Berks, G.

    2000-01-01

    A web-based software model (http://fuzzy.iau.dtu.dk/aphasia.nsf) was developed as an example for classification of aphasia using neural networks. Two multilayer perceptrons were used to classify the type of aphasia (Broca, Wernicke, anomic, global) according to the results in some subtests...

  16. Neural correlates of viewing paintings

    DEFF Research Database (Denmark)

    Vartanian, Oshin; Skov, Martin

    2014-01-01

    Many studies involving functional magnetic resonance imaging (fMRI) have exposed participants to paintings under varying task demands. To isolate neural systems that are activated reliably across fMRI studies in response to viewing paintings regardless of variation in task demands, a quantitative...

  17. Neural Basis of Visual Distraction

    Science.gov (United States)

    Kim, So-Yeon; Hopfinger, Joseph B.

    2010-01-01

    The ability to maintain focus and avoid distraction by goal-irrelevant stimuli is critical for performing many tasks and may be a key deficit in attention-related problems. Recent studies have demonstrated that irrelevant stimuli that are consciously perceived may be filtered out on a neural level and not cause the distraction triggered by…

  18. Spin glasses and neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Parga, N. (Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche; Universidad Nacional de Cuyo, San Carlos de Bariloche (Argentina). Inst. Balseiro)

    1989-07-01

    The mean-field theory of spin glass models has been used as a prototype of systems with frustration and disorder. One of the most interesting related systems are models of associative memories. In these lectures we review the main concepts developed to solve the Sherrington-Kirkpatrick model and its application to neural networks. (orig.).

  19. Artificial neural networks in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.

    1994-07-01

    This Technology Brief provides an overview of artificial neural networks (ANN). A definition and explanation of an ANN is given and situations in which an ANN is used are described. ANN applications to medicine specifically are then explored and the areas in which it is currently being used are discussed. Included are medical diagnostic aides, biochemical analysis, medical image analysis and drug development.

  20. Memory Storage and Neural Systems.

    Science.gov (United States)

    Alkon, Daniel L.

    1989-01-01

    Investigates memory storage and molecular nature of associative-memory formation by analyzing Pavlovian conditioning in marine snails and rabbits. Presented is the design of a computer-based memory system (neural networks) using the rules acquired in the investigation. Reports that the artificial network recognized patterns well. (YP)

  1. Multiprocessor Realization of Neural Networks

    Science.gov (United States)

    1990-04-01

    the unique capabilities of receiving, processing, and transmitting electo-chemical signals. These signals are sent over neural pathways that make up...these switching nodes and a clever arrangement of internode links to guaranteee at least one’ path between each processor and memory. These types of

  2. Move Ordering using Neural Networks

    NARCIS (Netherlands)

    Kocsis, L.; Uiterwijk, J.; Van Den Herik, J.

    2001-01-01

    © Springer-Verlag Berlin Heidelberg 2001. The efficiency of alpha-beta search algorithms heavily depends on the order in which the moves are examined. This paper focuses on using neural networks to estimate the likelihood of a move being the best in a certain position. The moves considered more like

  3. Serotonin, neural markers and memory

    Directory of Open Access Journals (Sweden)

    Alfredo eMeneses

    2015-07-01

    Full Text Available Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The interactions among behavioral tasks, control groups and molecular changes and/or pharmacological effects are mentioned. Neurotransmitter receptors and signaling pathways, during normal and abnormally functioning memory with an emphasis on the behavioral aspects of memory are revised. With focus on serotonin, since as it is a well characterized neurotransmitter, with multiple pharmacological tools, and well characterized downstream signaling in mammals’ species. 5-HT1A, 5-HT4, 5-HT5, 5-HT6 and 5-HT7 receptors as well as SERT (serotonin transporter seem to be useful neural markers and/or therapeutic targets. Certainly, if the mentioned evidence is replicated, then the translatability from preclinical and clinical studies to neural changes might be confirmed. Hypothesis and theories might provide appropriate limits and perspectives of evidence

  4. Neural Network based Consumption Forecasting

    DEFF Research Database (Denmark)

    Madsen, Per Printz

    2016-01-01

    This paper describe a Neural Network based method for consumption forecasting. This work has been financed by the The ENCOURAGE project. The aims of The ENCOURAGE project is to develop embedded intelligence and integration technologies that will directly optimize energy use in buildings and enable...

  5. Chronic hypersensitivity pneumonitis

    Science.gov (United States)

    Pereira, Carlos AC; Gimenez, Andréa; Kuranishi, Lilian; Storrer, Karin

    2016-01-01

    Hypersensitivity pneumonitis (HSP) is a common interstitial lung disease resulting from inhalation of a large variety of antigens by susceptible individuals. The disease is best classified as acute and chronic. Chronic HSP can be fibrosing or not. Fibrotic HSP has a large differential diagnosis and has a worse prognosis. The most common etiologies for HSP are reviewed. Diagnostic criteria are proposed for both chronic forms based on exposure, lung auscultation, lung function tests, HRCT findings, bronchoalveolar lavage, and biopsies. Treatment options are limited, but lung transplantation results in greater survival in comparison to idiopathic pulmonary fibrosis. Randomized trials with new antifibrotic agents are necessary. PMID:27703382

  6. The neural crest and neural crest cells: discovery and significance for theories of embryonic organization

    Indian Academy of Sciences (India)

    Brian K Hall

    2008-12-01

    The neural crest has long fascinated developmental biologists, and, increasingly over the past decades, evolutionary and evolutionary developmental biologists. The neural crest is the name given to the fold of ectoderm at the junction between neural and epidermal ectoderm in neurula-stage vertebrate embryos. In this sense, the neural crest is a morphological term akin to head fold or limb bud. This region of the dorsal neural tube consists of neural crest cells, a special population(s) of cell, that give rise to an astonishing number of cell types and to an equally astonishing number of tissues and organs. Neural crest cell contributions may be direct — providing cells — or indirect — providing a necessary, often inductive, environment in which other cells develop. The enormous range of cell types produced provides an important source of evidence of the neural crest as a germ layer, bringing the number of germ layers to four — ectoderm, endoderm, mesoderm, and neural crest. In this paper I provide a brief overview of the major phases of investigation into the neural crest and the major players involved, discuss how the origin of the neural crest relates to the origin of the nervous system in vertebrate embryos, discuss the impact on the germ-layer theory of the discovery of the neural crest and of secondary neurulation, and present evidence of the neural crest as the fourth germ layer. A companion paper (Hall, Evol. Biol. 2008) deals with the evolutionary origins of the neural crest and neural crest cells.

  7. Transplanted neural stem/precursor cells instruct phagocytes and reduce secondary tissue damage in the injured spinal cord.

    Science.gov (United States)

    Cusimano, Melania; Biziato, Daniela; Brambilla, Elena; Donegà, Matteo; Alfaro-Cervello, Clara; Snider, Silvia; Salani, Giuliana; Pucci, Ferdinando; Comi, Giancarlo; Garcia-Verdugo, Jose Manuel; De Palma, Michele; Martino, Gianvito; Pluchino, Stefano

    2012-02-01

    Transplanted neural stem/precursor cells possess peculiar therapeutic plasticity and can simultaneously instruct several therapeutic mechanisms in addition to cell replacement. Here, we interrogated the therapeutic plasticity of neural stem/precursor cells after their focal implantation in the severely contused spinal cord. We injected syngeneic neural stem/precursor cells at the proximal and distal ends of the contused mouse spinal cord and analysed locomotor functions and relevant secondary pathological events in the mice, cell fate of transplanted neural stem/precursor cells, and gene expression and inflammatory cell infiltration at the injured site. We used two different doses of neural stem/precursor cells and two treatment schedules, either subacute (7 days) or early chronic (21 days) neural stem/precursor cell transplantation after the induction of experimental thoracic severe spinal cord injury. Only the subacute transplant of neural stem/precursor cells enhanced the recovery of locomotor functions of mice with spinal cord injury. Transplanted neural stem/precursor cells survived undifferentiated at the level of the peri-lesion environment and established contacts with endogenous phagocytes via cellular-junctional coupling. This was associated with significant modulation of the expression levels of important inflammatory cell transcripts in vivo. Transplanted neural stem/precursor cells skewed the inflammatory cell infiltrate at the injured site by reducing the proportion of 'classically-activated' (M1-like) macrophages, while promoting the healing of the injured cord. We here identify a precise window of opportunity for the treatment of complex spinal cord injuries with therapeutically plastic somatic stem cells, and suggest that neural stem/precursor cells have the ability to re-programme the local inflammatory cell microenvironment from a 'hostile' to an 'instructive' role, thus facilitating the healing or regeneration past the lesion.

  8. Neural networks and applications tutorial

    Science.gov (United States)

    Guyon, I.

    1991-09-01

    The importance of neural networks has grown dramatically during this decade. While only a few years ago they were primarily of academic interest, now dozens of companies and many universities are investigating the potential use of these systems and products are beginning to appear. The idea of building a machine whose architecture is inspired by that of the brain has roots which go far back in history. Nowadays, technological advances of computers and the availability of custom integrated circuits, permit simulations of hundreds or even thousands of neurons. In conjunction, the growing interest in learning machines, non-linear dynamics and parallel computation spurred renewed attention in artificial neural networks. Many tentative applications have been proposed, including decision systems (associative memories, classifiers, data compressors and optimizers), or parametric models for signal processing purposes (system identification, automatic control, noise canceling, etc.). While they do not always outperform standard methods, neural network approaches are already used in some real world applications for pattern recognition and signal processing tasks. The tutorial is divided into six lectures, that where presented at the Third Graduate Summer Course on Computational Physics (September 3-7, 1990) on Parallel Architectures and Applications, organized by the European Physical Society: (1) Introduction: machine learning and biological computation. (2) Adaptive artificial neurons (perceptron, ADALINE, sigmoid units, etc.): learning rules and implementations. (3) Neural network systems: architectures, learning algorithms. (4) Applications: pattern recognition, signal processing, etc. (5) Elements of learning theory: how to build networks which generalize. (6) A case study: a neural network for on-line recognition of handwritten alphanumeric characters.

  9. Fuzzy logic systems are equivalent to feedforward neural networks

    Institute of Scientific and Technical Information of China (English)

    李洪兴

    2000-01-01

    Fuzzy logic systems and feedforward neural networks are equivalent in essence. First, interpolation representations of fuzzy logic systems are introduced and several important conclusions are given. Then three important kinds of neural networks are defined, i.e. linear neural networks, rectangle wave neural networks and nonlinear neural networks. Then it is proved that nonlinear neural networks can be represented by rectangle wave neural networks. Based on the results mentioned above, the equivalence between fuzzy logic systems and feedforward neural networks is proved, which will be very useful for theoretical research or applications on fuzzy logic systems or neural networks by means of combining fuzzy logic systems with neural networks.

  10. Chronic Fatigue Syndrome

    Science.gov (United States)

    Chronic fatigue syndrome (CFS) is a disorder that causes extreme fatigue. This fatigue is not the kind of tired feeling that ... activities. The main symptom of CFS is severe fatigue that lasts for 6 months or more. You ...

  11. Chronic Kidney Disease

    Science.gov (United States)

    You have two kidneys, each about the size of your fist. Their main job is to filter wastes and excess water out of ... help control blood pressure, and make hormones. Chronic kidney disease (CKD) means that your kidneys are damaged ...

  12. Chronic sinusitis (image)

    Science.gov (United States)

    ... and cartilage and lined with a mucous membrane. Sinusitis occurs when the membranes becomes inflamed and painful, ... a result of a blocked sinus opening. Chronic sinusitis is often caused by inflammation and blockage due ...

  13. Chronic Condition Data Warehouse

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Chronic Condition Data Warehouse (CCW) provides researchers with Medicare and Medicaid beneficiary, claims, and assessment data linked by beneficiary across...

  14. Zabofloxacin for chronic bronchitis.

    Science.gov (United States)

    Kocsis, B; Szabo, D

    2016-09-01

    Treatment of lower respiratory tract infection poses as an ongoing challenge among respiratory tract diseases. Bacterial infections are causes of acute exacerbations in chronic bronchitis and indications for antibacterial therapy. Several antibiotics were applied to treat bacterial infections in chronic bronchitis, among them fluoroquinolones are considered potent, broad-spectrum agents with excellent tissue penetration. This monograph focuses on zabofloxacin, a novel fluoroquinolone agent recently approved and launched in South Korea, and summarizes the drug's antibacterial efficacy, pharmacokinetic properties and toxicity. Recent advances concerning fluoroquinolones in chronic bronchitis will be discussed, along with a comparison between zabofloxacin and moxifloxacin. Zabofloxacin has proved to be noninferior to moxifloxacin against major community-acquired Gram-positive and Gram-negative respiratory tract pathogens and found to be well tolerated in both oral and parenteral administrations. These features can make it a potential antimicrobial agent in therapy of chronic bronchitis and other lower respiratory tract infections.

  15. Living with Chronic Bronchitis

    Science.gov (United States)

    ... Health Topics » Bronchitis » Living With Chronic Bronchitis Explore Bronchitis What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics ...

  16. Chronic Critical Illness

    Science.gov (United States)

    ... the patient’s situation and on the hospital and city. Do Chronically Critically Ill Patients Regain the Ability ... as the patient. You may feel stress, worry, sadness, or fatigue. Some families worry about financial burdens. ...

  17. Chronic Conditions Dashboard

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Chronic Conditions Dashboard presents statistical views of information on the prevalence, utilization and Medicare spending for Medicare beneficiaries with...

  18. Chronic Myeloproliferative Neoplasms Treatment

    Science.gov (United States)

    ... way to treat some chronic myeloproliferative neoplasms. Platelet apheresis Platelet apheresis is a treatment that uses a special machine ... using interferon alfa or pegylated interferon alpha . Platelet apheresis . A clinical trial of a new treatment. Check ...

  19. Chronic penile strangulation

    Directory of Open Access Journals (Sweden)

    Lopes Roberto I

    2003-01-01

    Full Text Available Chronic penile strangulation is exceedingly rare with only 5 cases previously reported. We report an additional case of progressive penile lymphedema due to chronic intermittent strangulation caused by a rubber band applied to the penile base for 6 years. A 49-year-old man presented incapacity to exteriorize the glans penis. For erotic purposes, he had been using a rubber-enlarging band placed in the penile base for 6 years. With chronic use, he noticed that his penis swelled. Physical examination revealed lymphedema of the penis, phimosis and a stricture in the penile base. The patient was submitted to circumcision and the lymphedema remained stable 10 months postoperatively. Chronic penile incarceration usually causes penile lymphedema and urinary disturbance. Treatment consists of removal of foreign devices and surgical treatment of lymphedema.

  20. Chronic Illness & Mental Health

    Science.gov (United States)

    ... is present. For More Information Share Chronic Illness & Mental Health Download PDF Download ePub Order a free hardcopy ... For more information, see the National Institute of Mental Health (NIMH) booklet on Depression at http://www.nimh. ...

  1. Chronic obstructive pulmonary disease

    Science.gov (United States)

    ... and oxygen therapy Right-sided heart failure or cor pulmonale (heart swelling and heart failure due to chronic ... PA: Elsevier Saunders; 2016:chap 44. Read More Cor pulmonale Dilated cardiomyopathy Heart failure - overview Lung disease Patient ...

  2. Chronic Kidney Disease (CKD)

    Science.gov (United States)

    ... CKD treated? Kidney-friendly diet for CKD What causes chronic kidney disease (CKD)? Anyone can get CKD. Some people are ... and high blood pressure are the most common causes of CKD. If you have diabetes or high blood pressure, ...

  3. Sleep and Chronic Disease

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . Sleep About Us About Sleep Key Sleep Disorders Sleep ... Sheets Data & Statistics Projects and Partners Resources Events Sleep and Chronic Disease Recommend on Facebook Tweet Share ...

  4. Chronic Conditions PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Chronic Conditions PUFs are aggregated files in which each record is a profile or cell defined by the characteristics of Medicare beneficiaries. A profile is...

  5. Chronic inflammatory demyelinative polyneuropathy

    DEFF Research Database (Denmark)

    Said, Gérard; Krarup, Christian

    2013-01-01

    Chronic inflammatory demyelinative polyneuropathy (CIDP) is an acquired polyneuropathy presumably of immunological origin. It is characterized by a progressive or a relapsing course with predominant motor deficit. The diagnosis rests on the association of non-length-dependent predominantly motor ...

  6. Chronic dysimmune neuropathies: Beyond chronic demyelinating polyradiculoneuropathy

    Directory of Open Access Journals (Sweden)

    Khadilkar Satish

    2011-01-01

    Full Text Available The spectrum of chronic dysimmune neuropathies has widened well beyond chronic demyelinating polyradiculoneuropathy (CIDP. Pure motor (multifocal motor neuropathy, sensorimotor with asymmetrical involvement (multifocal acquired demylinating sensory and motor neuropathy, exclusively distal sensory (distal acquired demyelinating sensory neuropathy and very proximal sensory (chronic immune sensory polyradiculopathy constitute the variants of CIDP. Correct diagnosis of these entities is of importance in terms of initiation of appropriate therapy as well as prognostication of these patients. The rates of detection of immune-mediated neuropathies with monoclonal cell proliferation (monoclonal gammopathy of unknown significance, multiple myeloma, etc. have been facilitated as better diagnostic tools such as serum immunofixation electrophoresis are being used more often. Immune neuropathies associated with malignancies and systemic vasculitic disorders are being defined further and treated early with better understanding of the disease processes. As this field of dysimmune neuropathies will evolve in the future, some of the curious aspects of the clinical presentations and response patterns to different immunosuppressants or immunomodulators will be further elucidated. This review also discusses representative case studies.

  7. Tolerance and chronic rejection.

    OpenAIRE

    Womer, K. L.; Lee, R S; Madsen, J. C.; Sayegh, M H

    2001-01-01

    The most common cause of chronic allograft loss is an incompletely understood clinicopathological entity called chronic rejection (CR). Recent reports suggest an improvement in long-term renal allograft survival, although it is not clear from these data whether a true reduction of biopsy-proven CR has occurred. Although newer immunosuppressive medications have greatly reduced the incidence of acute rejection (AR) in the early post-transplantation period, the ideal therapy for both AR and CR w...

  8. Chronic obstructive pulmonary disease

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008430 Effect of gas exchange at maximal intensity on exercise capacity in patients with chronic obstructive pulmonary disease. WANG Haoyan(王浩彦), et al. Dept Respir Dis, Beijing Friendship Hosp, Capital Med Sci Univ, Beijing 100050. Chin J Tuberc Respir Dis 2008;31(6):414-416. Objective To investigate the effect of gas exchange at maximal intensity on exercise capacity in patients with chronic obstructive pulmonary disease (COPD).

  9. Experimental chronic periodontitis morphogenesis

    OpenAIRE

    Schneider S.A.

    2011-01-01

    Morphogenesis of periodontium tissue in a model of chronic periodontitis was studied. Adult Wistar rats wereused in a model; chronic periodontitis was developed through mastication-related loading decrease. Histological assessmentof periodontium tissue was conducted at Days 7, 14, 21 and 30. It was demonstrated that dystrophic tissue changes prevailover the inflammatory one in this particular experimental model. The structural elements of periodontium were involved intothe pathologic process ...

  10. Understanding chronic heart failure

    OpenAIRE

    Fenton, Matthew; Burch, Michael

    2007-01-01

    The key principles of chronic heart failure and the development of clinical management strategies are described. The physiological changes in chronic heart failure and the clinical management of children with heart failure are considered, but the treatment of heart failure related to congenital heart disease or the intensive care management of heart failure are not mentioned as both topics require consideration in their own right. A greater understanding of the maladaptive responses to chroni...

  11. Treatment of Chronic Cough.

    Science.gov (United States)

    Soni, Resha S; Ebersole, Barbara; Jamal, Nausheen

    2017-01-01

    Objective Chronic cough remains a challenging condition, especially in cases where it persists despite comprehensive medical management. For these particular patients, there appears to be an emerging role for behavior modification therapy. We report a series of patients with refractory chronic cough to assess if there is any benefit of adding behavioral therapy to their treatment regimen. Study Design A case series with planned chart review of patients treated for chronic cough. Setting The review was performed with an outpatient electronic health record system at a tertiary care center. Subjects and Methods The charts of all patients treated for chronic cough by a single laryngologist over a 30-month period were analyzed. Patients' response to treatment and rate of cough improvement were assessed for those with refractory chronic cough who underwent behavior modification therapy. Results Thirty-eight patients with chronic cough were initially treated empirically for the most common causes of cough, of which 32% experienced improvement. Nineteen patients who did not significantly improve with medical management underwent behavior modification therapy with a speech-language pathologist. Of these patients, 84% experienced resolution or marked improvement of their symptoms. Conclusion Behavioral therapy may be underutilized in practice and could lead to improvement of otherwise recalcitrant cough.

  12. On neural networks that design neural associative memories.

    Science.gov (United States)

    Chan, H Y; Zak, S H

    1997-01-01

    The design problem of generalized brain-state-in-a-box (GBSB) type associative memories is formulated as a constrained optimization program, and "designer" neural networks for solving the program in real time are proposed. The stability of the designer networks is analyzed using Barbalat's lemma. The analyzed and synthesized neural associative memories do not require symmetric weight matrices. Two types of the GBSB-based associative memories are analyzed, one when the network trajectories are constrained to reside in the hypercube [-1, 1](n) and the other type when the network trajectories are confined to stay in the hypercube [0, 1](n). Numerical examples and simulations are presented to illustrate the results obtained.

  13. Neurale Netwerken en Radarsystemen (Neural Networks and Radar Systems)

    Science.gov (United States)

    1989-08-01

    34 on "godistribucord geheugon" (zie hoofdstuk 5). Neurologiach on psychologisch ondorzoek dienden bij doze vorm van onderzoek alechta ala...momenteel geen goede algoritmen bekend zijn. Een voorbeeld hiervan is het herkennen van typen objecten aon do hand van gebrekkige, onnauvkeurige of gestoorde...valt onder meer to denken aan do betrouwbaarheld van neurale netwerken. Hot is bekond dat sommige typen netwerken nog steeds redelijk good functioneren

  14. In vitro and in vivo analysis and characterization of engineered spinal neural implants (Conference Presentation)

    Science.gov (United States)

    Shor, Erez; Shoham, Shy; Levenberg, Shulamit

    2016-03-01

    Spinal cord injury is a devastating medical condition. Recent developments in pre-clinical and clinical research have started to yield neural implants inducing functional recovery after spinal cord transection injury. However, the functional performance of the transplants was assessed using histology and behavioral experiments which are unable to study cell dynamics and the therapeutic response. Here, we use neurophotonic tools and optogenetic probes to investigate cellular level morphology and activity characteristics of neural implants over time at the cellular level. These methods were used in-vitro and in-vivo, in a mouse spinal cord injury implant model. Following previous attempts to induce recovery after spinal cord injury, we engineered a pre-vascularized implant to obtain better functional performance. To image network activity of a construct implanted in a mouse spinal cord, we transfected the implant to express GCaMP6 calcium activity indicators and implanted these constructs under a spinal cord chamber enabling 2-photon chronic in vivo neural activity imaging. Activity and morphology analysis image processing software was developed to automatically quantify the behavior of the neural and vascular networks. Our experimental results and analyses demonstrate that vascularized and non-vascularized constructs exhibit very different morphologic and activity patterns at the cellular level. This work enables further optimization of neural implants and also provides valuable tools for continuous cellular level monitoring and evaluation of transplants designed for various neurodegenerative disease models.

  15. Architecture and biological applications of artificial neural networks: a tuberculosis perspective.

    Science.gov (United States)

    Darsey, Jerry A; Griffin, William O; Joginipelli, Sravanthi; Melapu, Venkata Kiran

    2015-01-01

    Advancement of science and technology has prompted researchers to develop new intelligent systems that can solve a variety of problems such as pattern recognition, prediction, and optimization. The ability of the human brain to learn in a fashion that tolerates noise and error has attracted many researchers and provided the starting point for the development of artificial neural networks: the intelligent systems. Intelligent systems can acclimatize to the environment or data and can maximize the chances of success or improve the efficiency of a search. Due to massive parallelism with large numbers of interconnected processers and their ability to learn from the data, neural networks can solve a variety of challenging computational problems. Neural networks have the ability to derive meaning from complicated and imprecise data; they are used in detecting patterns, and trends that are too complex for humans, or other computer systems. Solutions to the toughest problems will not be found through one narrow specialization; therefore we need to combine interdisciplinary approaches to discover the solutions to a variety of problems. Many researchers in different disciplines such as medicine, bioinformatics, molecular biology, and pharmacology have successfully applied artificial neural networks. This chapter helps the reader in understanding the basics of artificial neural networks, their applications, and methodology; it also outlines the network learning process and architecture. We present a brief outline of the application of neural networks to medical diagnosis, drug discovery, gene identification, and protein structure prediction. We conclude with a summary of the results from our study on tuberculosis data using neural networks, in diagnosing active tuberculosis, and predicting chronic vs. infiltrative forms of tuberculosis.

  16. Neural Excitability and Singular Bifurcations.

    Science.gov (United States)

    De Maesschalck, Peter; Wechselberger, Martin

    2015-12-01

    We discuss the notion of excitability in 2D slow/fast neural models from a geometric singular perturbation theory point of view. We focus on the inherent singular nature of slow/fast neural models and define excitability via singular bifurcations. In particular, we show that type I excitability is associated with a novel singular Bogdanov-Takens/SNIC bifurcation while type II excitability is associated with a singular Andronov-Hopf bifurcation. In both cases, canards play an important role in the understanding of the unfolding of these singular bifurcation structures. We also explain the transition between the two excitability types and highlight all bifurcations involved, thus providing a complete analysis of excitability based on geometric singular perturbation theory.

  17. Neural Networks Methodology and Applications

    CERN Document Server

    Dreyfus, Gérard

    2005-01-01

    Neural networks represent a powerful data processing technique that has reached maturity and broad application. When clearly understood and appropriately used, they are a mandatory component in the toolbox of any engineer who wants make the best use of the available data, in order to build models, make predictions, mine data, recognize shapes or signals, etc. Ranging from theoretical foundations to real-life applications, this book is intended to provide engineers and researchers with clear methodologies for taking advantage of neural networks in industrial, financial or banking applications, many instances of which are presented in the book. For the benefit of readers wishing to gain deeper knowledge of the topics, the book features appendices that provide theoretical details for greater insight, and algorithmic details for efficient programming and implementation. The chapters have been written by experts ands seemlessly edited to present a coherent and comprehensive, yet not redundant, practically-oriented...

  18. Neural Network for Sparse Reconstruction

    Directory of Open Access Journals (Sweden)

    Qingfa Li

    2014-01-01

    Full Text Available We construct a neural network based on smoothing approximation techniques and projected gradient method to solve a kind of sparse reconstruction problems. Neural network can be implemented by circuits and can be seen as an important method for solving optimization problems, especially large scale problems. Smoothing approximation is an efficient technique for solving nonsmooth optimization problems. We combine these two techniques to overcome the difficulties of the choices of the step size in discrete algorithms and the item in the set-valued map of differential inclusion. In theory, the proposed network can converge to the optimal solution set of the given problem. Furthermore, some numerical experiments show the effectiveness of the proposed network in this paper.

  19. Fiber optic Adaline neural networks

    Science.gov (United States)

    Ghosh, Anjan K.; Trepka, Jim; Paparao, Palacharla

    1993-02-01

    Optoelectronic realization of adaptive filters and equalizers using fiber optic tapped delay lines and spatial light modulators has been discussed recently. We describe the design of a single layer fiber optic Adaline neural network which can be used as a bit pattern classifier. In our realization we employ as few electronic devices as possible and use optical computation to utilize the advantages of optics in processing speed, parallelism, and interconnection. The new optical neural network described in this paper is designed for optical processing of guided lightwave signals, not electronic signals. We analyzed the convergence or learning characteristics of the optically implemented Adaline in the presence of errors in the hardware, and we studied methods for improving the convergence rate of the Adaline.

  20. Neural mechanisms of communicative innovation.

    Science.gov (United States)

    Stolk, Arjen; Verhagen, Lennart; Schoffelen, Jan-Mathijs; Oostenveld, Robert; Blokpoel, Mark; Hagoort, Peter; van Rooij, Iris; Toni, Ivan

    2013-09-01

    Human referential communication is often thought as coding-decoding a set of symbols, neglecting that establishing shared meanings requires a computational mechanism powerful enough to mutually negotiate them. Sharing the meaning of a novel symbol might rely on similar conceptual inferences across communicators or on statistical similarities in their sensorimotor behaviors. Using magnetoencephalography, we assess spectral, temporal, and spatial characteristics of neural activity evoked when people generate and understand novel shared symbols during live communicative interactions. Solving those communicative problems induced comparable changes in the spectral profile of neural activity of both communicators and addressees. This shared neuronal up-regulation was spatially localized to the right temporal lobe and the ventromedial prefrontal cortex and emerged already before the occurrence of a specific communicative problem. Communicative innovation relies on neuronal computations that are shared across generating and understanding novel shared symbols, operating over temporal scales independent from transient sensorimotor behavior.

  1. Genetic attack on neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

    2006-03-01

    Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

  2. The Physics of Neural Networks

    Science.gov (United States)

    Gutfreund, Hanoch; Toulouse, Gerard

    The following sections are included: * Introduction * Historical Perspective * Why Statistical Physics? * Purpose and Outline of the Paper * Basic Elements of Neural Network Models * The Biological Neuron * From the Biological to the Formal Neuron * The Formal Neuron * Network Architecture * Network Dynamics * Basic Functions of Neural Network Models * Associative Memory * Learning * Categorization * Generalization * Optimization * The Hopfield Model * Solution of the Model * The Merit of the Hopfield Model * Beyond the Standard Model * The Gardner Approach * A Microcanonical Formulation * The Case of Biased Patterns * A Canonical Formulation * Constraints on the Synaptic Weights * Learning with Errors * Learning with Noise * Hierarchically Correlated Data and Categorization * Hierarchical Data Structures * Storage of Hierarchical Data Structures * Categorization * Generalization * Learning a Classification Task * The Reference Perceptron Problem * The Contiguity Problem * Discussion - Issues of Relevance * The Notion of Attractors and Modes of Computation * The Nature of Attractors * Temporal versus Spatial Coding * Acknowledgements * References

  3. Template learning in morphological neural nets

    Science.gov (United States)

    Davidson, Jennifer L.; Sun, K.

    1991-07-01

    This paper presents an application of morphology neural networks to a template learning problem. Morphology neural networks are a nonlinear version of the familiar artificial neural networks. Typically, an artificial neural net is used to solve pattern classification problems One useful characterization of many neural network algorithms is the ability to 'learn' to respond correctly to new data based only on a selection of known data responses. For example, in the multilayer perceptron model, the 'learning' is a procedure whereby parameters are fed back from output to input neurons and the weights changed to give a better response. The morphological neural net in this paper solves a different type of image processing problem. Specifically, given an input image and an output image which corresponds to a dilated version of the input, one would like to determine what template produced the output. The problem corresponds to teaching the network to solve for the weights in a morphological net, as the weights are the template's values. A reasonable method has been investigated for the boolean case; in this paper results are presented for gray scale images. Image algebra has been shown to provide a succinct expression of neural networks algorithms and also to allow a generalization of neural networks, and thus the authors describe the algorithm in image algebra. The remainder of the paper gives a brief discussion of image algebra, the relationship of image algebra and neural networks, a recap of the dilation morphology neural network boolean for boolean images, and the generalization to grayscale data.

  4. Adaptive Regularization of Neural Classifiers

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; Larsen, Jan; Hansen, Lars Kai

    1997-01-01

    We present a regularization scheme which iteratively adapts the regularization parameters by minimizing the validation error. It is suggested to use the adaptive regularization scheme in conjunction with optimal brain damage pruning to optimize the architecture and to avoid overfitting. Furthermo......, we propose an improved neural classification architecture eliminating an inherent redundancy in the widely used SoftMax classification network. Numerical results demonstrate the viability of the method...

  5. Handbook on neural information processing

    CERN Document Server

    Maggini, Marco; Jain, Lakhmi

    2013-01-01

    This handbook presents some of the most recent topics in neural information processing, covering both theoretical concepts and practical applications. The contributions include:                         Deep architectures                         Recurrent, recursive, and graph neural networks                         Cellular neural networks                         Bayesian networks                         Approximation capabilities of neural networks                         Semi-supervised learning                         Statistical relational learning                         Kernel methods for structured data                         Multiple classifier systems                         Self organisation and modal learning                         Applications to ...

  6. Analog electronic neural network circuits

    Energy Technology Data Exchange (ETDEWEB)

    Graf, H.P.; Jackel, L.D. (AT and T Bell Labs., Holmdel, NJ (USA))

    1989-07-01

    The large interconnectivity and moderate precision required in neural network models present new opportunities for analog computing. This paper discusses analog circuits for a variety of problems such as pattern matching, optimization, and learning. Most of the circuits build so far are relatively small, exploratory designs. The most mature circuits are those for template matching. Chips performing this function are now being applied to pattern recognition problems.

  7. Neural Networks for Speech Application.

    Science.gov (United States)

    1987-11-01

    operation and neurocrience theories of how neurons process information in the brain. design. Early studies by McCulloch and Pitts dunng the forties led to...developed the commercially available Mark III and Mark IV neurocom- established by McCulloch and Pits. puters that model neural networks and run...ORGANIZERS Infonuiaonienes (1986) FOR Lashley, K. Brain Mehaius and Cblali (129)SPEECHOTECH 󈨜 McCullch. W and Pitts . W, ’A Logical Calculusof the

  8. [Neural basis of maternal behavior].

    Science.gov (United States)

    Noriuchi, Madoka; Kikuchi, Yoshiaki

    2013-01-01

    Maternal love, which may be the core of maternal behavior, is essential for the mother-infant attachment relationship and is important for the infant's development and mental health. However, little has been known about these neural mechanisms in human mothers. We examined patterns of maternal brain activation in response to infant cues using video clips. We performed functional magnetic resonance imaging (fMRI) measurements while 13 mothers viewed video clips, with no sound, of their own infant and other infants of approximately 16 months of age who demonstrated two different attachment behaviors (smiling at the infant's mother and crying for her). We found that a limited number of the mother's brain areas were specifically involved in recognition of the mother's own infant, namely orbitofrontal cortex (OFC). and periaqueductal gray, anterior insula, and dorsal and ventrolateral parts of putamen. Additionally, we found the strong and specific mother's brain response for the mother's own infant's distress. The differential neural activation pattern was found in the dorsal region of OFC, caudate nucleus, right inferior frontal gyrus, dorsomedial prefrontal cortex (PFC), anterior cingulate, posterior cingulate, posterior superior temporal sulcus, and dorsolateral PFC. Our results showed the highly elaborate neural mechanism mediating maternal love and diverse and complex maternal behaviors for vigilant protectiveness.

  9. Neural Representations of Physics Concepts.

    Science.gov (United States)

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems.

  10. Neural mechanisms of mental fatigue.

    Science.gov (United States)

    Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi

    2014-01-01

    Fatigue is defined as a decline in the ability and efficiency of mental and/or physical activities that is caused by excessive mental and/or physical activities. Fatigue can be classified as physical or mental. Mental fatigue manifests as potentially impaired cognitive function and is one of the most significant causes of accidents in modern society. Recently, it has been shown that the neural mechanisms of mental fatigue related to cognitive task performance are more complex than previously thought and that mental fatigue is not caused only by impaired activity in task-related brain regions. There is accumulating evidence supporting the existence of mental facilitation and inhibition systems. These systems are involved in the neural mechanisms of mental fatigue, modulating the activity of task-related brain regions to regulate cognitive task performance. In this review, we propose a new conceptual model: the dual regulation system of mental fatigue. This model contributes to our understanding of the neural mechanisms of mental fatigue and the regulatory mechanisms of cognitive task performance in the presence of mental fatigue.

  11. Chronic prostatitis: Current concepts

    Directory of Open Access Journals (Sweden)

    Ram Vaidyanathan

    2008-01-01

    Full Text Available Purpose: Chronic prostatitis (CP is a common condition. It causes significant suffering to the patients and constitutes a sizeable workload for the urologists. The purpose of this review is to describe the currently accepted concepts regarding the aspects of CP. Materials and Methods: Relevant papers on the epidemiology, etiology, diagnosis, evaluation and management of CP were identified through a search of MEDLINE using text terms "prostatitis", "chronic prostatitis" and "chronic pelvic pain syndrome". The list of articles thus obtained was supplemented by manual search of bibliographies of the identified articles and also by exploring the MEDLINE option "Related Articles". Results: The salient points of the relevant articles on each aspect of CP have been summarized in the form of a non-systematic narrative review. Conclusion: Chronic prostatitis is caused by a variety of infective and non-infective factors and is characterized by a rather long remitting and relapsing clinical course. The diagnosis is based on symptoms comprising pain and nonspecific urinary and/or ejaculatory disturbances and microbiological tests to localize bacteria and/or leucocytes in segmented urinary tract specimens. The contemporary classification was proposed by the National Institutes of Health/National Institute of Diabetes Digestive Kidney Diseases (NIH/NIDDK. National Institutes of Health - Chronic Prostatitis Symptom Index (NIH-CPSI is the patient evaluation tool used extensively in clinical practice and research. Management should be individualized, multimodal and of an appropriate duration.

  12. Autoantibodies in chronic pancreatitis

    DEFF Research Database (Denmark)

    Rumessen, J J; Marner, B; Pedersen, N T

    1985-01-01

    In 60 consecutive patients clinically suspected of having chronic pancreatitis the serum concentration of the immunoglobulins (IgA, IgG, IgM), the IgG- and IgA-type non-organ-specific autoantibodies against nuclear material (ANA), smooth and striated muscle, mitochondria, basal membrane, and reti......In 60 consecutive patients clinically suspected of having chronic pancreatitis the serum concentration of the immunoglobulins (IgA, IgG, IgM), the IgG- and IgA-type non-organ-specific autoantibodies against nuclear material (ANA), smooth and striated muscle, mitochondria, basal membrane......, and reticulin, and the IgG- and IgA-type pancreas-specific antibodies against islet cells, acinus cells, and ductal cells (DA) were estimated blindly. In 23 of the patients chronic pancreatitis was verified, whereas chronic pancreatitis was rejected in 37 patients (control group). IgG and IgA were found...... in significantly higher concentrations in the patients with chronic pancreatitis than in the control group but within the normal range. ANA and DA occurred very frequently in both groups but with no statistical difference. Other autoantibodies only occurred sporadically. The findings of this study do not support...

  13. Management of chronic paronychia

    Directory of Open Access Journals (Sweden)

    Vineet Relhan

    2014-01-01

    Full Text Available Chronic paronychia is an inflammatory disorder of the nail folds of a toe or finger presenting as redness, tenderness, and swelling. It is recalcitrant dermatoses seen commonly in housewives and housemaids. It is a multifactorial inflammatory reaction of the proximal nail fold to irritants and allergens. Repeated bouts of inflammation lead to fibrosis of proximal nail fold with poor generation of cuticle, which in turn exposes the nail further to irritants and allergens. Thus, general preventive measures form cornerstone of the therapy. Though previously anti-fungals were the mainstay of therapy, topical steroid creams have been found to be more effective in the treatment of chronic paronychia. In recalcitrant cases, surgical treatment may be resorted to, which includes en bloc excision of the proximal nail fold or an eponychial marsupialization, with or without nail plate removal. Newer therapies and surgical modalities are being employed in the management of chronic paronychia. In this overview, we review recent epidemiological studies, present current thinking on the pathophysiology leading to chronic paronychia, discuss the challenges chronic paronychia presents, and recommend a commonsense approach to management.

  14. Chronic daily headaches

    Directory of Open Access Journals (Sweden)

    Fayyaz Ahmed

    2012-01-01

    Full Text Available Chronic Daily Headache is a descriptive term that includes disorders with headaches on more days than not and affects 4% of the general population. The condition has a debilitating effect on individuals and society through direct cost to healthcare and indirectly to the economy in general. To successfully manage chronic daily headache syndromes it is important to exclude secondary causes with comprehensive history and relevant investigations; identify risk factors that predict its development and recognise its sub-types to appropriately manage the condition. Chronic migraine, chronic tension-type headache, new daily persistent headache and medication overuse headache accounts for the vast majority of chronic daily headaches. The scope of this article is to review the primary headache disorders. Secondary headaches are not discussed except medication overuse headache that often accompanies primary headache disorders. The article critically reviews the literature on the current understanding of daily headache disorders focusing in particular on recent developments in the treatment of frequent headaches.

  15. Chronic hypersensitivity pneumonitis

    Directory of Open Access Journals (Sweden)

    Pereira CA

    2016-09-01

    Full Text Available Carlos AC Pereira,1 Andréa Gimenez,2 Lilian Kuranishi,2 Karin Storrer 2 1Interstitial Lung Diseases Program, 2Pulmonology Postgraduate, Federal University of São Paulo, São Paulo, Brazil Abstract: Hypersensitivity pneumonitis (HSP is a common interstitial lung disease resulting from inhalation of a large variety of antigens by susceptible individuals. The disease is best classified as acute and chronic. Chronic HSP can be fibrosing or not. Fibrotic HSP has a large differential diagnosis and has a worse prognosis. The most common etiologies for HSP are reviewed. Diagnostic criteria are proposed for both chronic forms based on exposure, lung auscultation, lung function tests, HRCT findings, bronchoalveolar lavage, and biopsies. Treatment options are limited, but lung transplantation results in greater survival in comparison to idiopathic pulmonary fibrosis. Randomized trials with new antifibrotic agents are necessary. Keywords: interstitial lung diseases, extrinsic allergic alveolitis, diffuse lung disease, lung immune response, HRCT, farmers lung

  16. Chronic pelvic floor dysfunction.

    Science.gov (United States)

    Hartmann, Dee; Sarton, Julie

    2014-10-01

    The successful treatment of women with vestibulodynia and its associated chronic pelvic floor dysfunctions requires interventions that address a broad field of possible pain contributors. Pelvic floor muscle hypertonicity was implicated in the mid-1990s as a trigger of major chronic vulvar pain. Painful bladder syndrome, irritable bowel syndrome, fibromyalgia, and temporomandibular jaw disorder are known common comorbidities that can cause a host of associated muscular, visceral, bony, and fascial dysfunctions. It appears that normalizing all of those disorders plays a pivotal role in reducing complaints of chronic vulvar pain and sexual dysfunction. Though the studies have yet to prove a specific protocol, physical therapists trained in pelvic dysfunction are reporting success with restoring tissue normalcy and reducing vulvar and sexual pain. A review of pelvic anatomy and common findings are presented along with suggested physical therapy management.

  17. Omalizumab for chronic urticaria

    DEFF Research Database (Denmark)

    Ivyanskiy, Ilya; Sand, Carsten; Thomsen, Simon Francis

    2012-01-01

    urticaria. We present a case series of 19 patients with chronic urticaria treated in a university department with omalizumab and give an overview of the existing literature comprising an additional 59 cases as well as a total of 139 patients enrolled in two randomized controlled trials comparing omalizumab...... with placebo. The collective evidence points to omalizumab as a safe and effective treatment option for patients with chronic urticaria who do not sufficiently respond to standard therapy as recommended by existing guidelines.......Omalizumab is a recombinant humanized monoclonal antibody that blocks the high-affinity Fc receptor of IgE. Omalizumab has been approved for the treatment of moderate to severe asthma; however, there is currently more and more data showing promising results in the management also of chronic...

  18. Democratic organization of the thalamocortical neural ensembles in nociceptive signal processing

    Institute of Scientific and Technical Information of China (English)

    LUO Fei; WANG Jin-Yan

    2008-01-01

    Acute pain is a warning protective sensation for any impending harm. However, chronic pain syndromes are often resistant diseases that may consume large amount of health care costs. It has been suggested by recent studies that pain perception may be formed in central neural networks via large-scale coding processes, which involves sensory, affective, and cognitive dimensions. Many central areas are involved in these processes, including structures from the spinal cord, the brain stem, the limbic system, to the cortices. Thus, chronic painful diseases may be the result of some abnormal coding within this network. A thorough investigation of coding mechanism of pain within the central neuromatrix will bring us great insight into the mechanisms responsible for the development of chronic pain, hence leading to novel therapeutic interventions for pain management.

  19. Dynamic Analysis of Structures Using Neural Networks

    Directory of Open Access Journals (Sweden)

    N. Ahmadi

    2008-01-01

    Full Text Available In the recent years, neural networks are considered as the best candidate for fast approximation with arbitrary accuracy in the time consuming problems. Dynamic analysis of structures against earthquake has the time consuming process. We employed two kinds of neural networks: Generalized Regression neural network (GR and Back-Propagation Wavenet neural network (BPW, for approximating of dynamic time history response of frame structures. GR is a traditional radial basis function neural network while BPW categorized as a wavelet neural network. In BPW, sigmoid activation functions of hidden layer neurons are substituted with wavelets and weights training are achieved using Scaled Conjugate Gradient (SCG algorithm. Comparison the results of BPW with those of GR in the dynamic analysis of eight story steel frame indicates that accuracy of the properly trained BPW was better than that of GR and therefore, BPW can be efficiently used for approximate dynamic analysis of structures.

  20. Coherence resonance in bursting neural networks.

    Science.gov (United States)

    Kim, June Hoan; Lee, Ho Jun; Min, Cheol Hong; Lee, Kyoung J

    2015-10-01

    Synchronized neural bursts are one of the most noticeable dynamic features of neural networks, being essential for various phenomena in neuroscience, yet their complex dynamics are not well understood. With extrinsic electrical and optical manipulations on cultured neural networks, we demonstrate that the regularity (or randomness) of burst sequences is in many cases determined by a (few) low-dimensional attractor(s) working under strong neural noise. Moreover, there is an optimal level of noise strength at which the regularity of the interburst interval sequence becomes maximal-a phenomenon of coherence resonance. The experimental observations are successfully reproduced through computer simulations on a well-established neural network model, suggesting that the same phenomena may occur in many in vivo as well as in vitro neural networks.

  1. Neurosecurity: security and privacy for neural devices.

    Science.gov (United States)

    Denning, Tamara; Matsuoka, Yoky; Kohno, Tadayoshi

    2009-07-01

    An increasing number of neural implantable devices will become available in the near future due to advances in neural engineering. This discipline holds the potential to improve many patients' lives dramatically by offering improved-and in some cases entirely new-forms of rehabilitation for conditions ranging from missing limbs to degenerative cognitive diseases. The use of standard engineering practices, medical trials, and neuroethical evaluations during the design process can create systems that are safe and that follow ethical guidelines; unfortunately, none of these disciplines currently ensure that neural devices are robust against adversarial entities trying to exploit these devices to alter, block, or eavesdrop on neural signals. The authors define "neurosecurity"-a version of computer science security principles and methods applied to neural engineering-and discuss why neurosecurity should be a critical consideration in the design of future neural devices.

  2. Effects of childhood poverty and chronic stress on emotion regulatory brain function in adulthood.

    Science.gov (United States)

    Kim, Pilyoung; Evans, Gary W; Angstadt, Michael; Ho, S Shaun; Sripada, Chandra S; Swain, James E; Liberzon, Israel; Phan, K Luan

    2013-11-12

    Childhood poverty has pervasive negative physical and psychological health sequelae in adulthood. Exposure to chronic stressors may be one underlying mechanism for childhood poverty-health relations by influencing emotion regulatory systems. Animal work and human cross-sectional studies both suggest that chronic stressor exposure is associated with amygdala and prefrontal cortex regions important for emotion regulation. In this longitudinal functional magnetic resonance imaging study of 49 participants, we examined associations between childhood poverty at age 9 and adult neural circuitry activation during emotion regulation at age 24. To test developmental timing, concurrent, adult income was included as a covariate. Adults with lower family income at age 9 exhibited reduced ventrolateral and dorsolateral prefrontal cortex activity and failure to suppress amygdala activation during effortful regulation of negative emotion at age 24. In contrast to childhood income, concurrent adult income was not associated with neural activity during emotion regulation. Furthermore, chronic stressor exposure across childhood (at age 9, 13, and 17) mediated the relations between family income at age 9 and ventrolateral and dorsolateral prefrontal cortex activity at age 24. The findings demonstrate the significance of childhood chronic stress exposures in predicting neural outcomes during emotion regulation in adults who grew up in poverty.

  3. Process Neural Networks Theory and Applications

    CERN Document Server

    He, Xingui

    2010-01-01

    "Process Neural Networks - Theory and Applications" proposes the concept and model of a process neural network for the first time, showing how it expands the mapping relationship between the input and output of traditional neural networks, and enhancing the expression capability for practical problems, with broad applicability to solving problems relating to process in practice. Some theoretical problems such as continuity, functional approximation capability, and computing capability, are strictly proved. The application methods, network construction principles, and optimization alg

  4. Rule Extraction using Artificial Neural Networks

    OpenAIRE

    2010-01-01

    Artificial neural networks have been successfully applied to a variety of business application problems involving classification and regression. Although backpropagation neural networks generally predict better than decision trees do for pattern classification problems, they are often regarded as black boxes, i.e., their predictions are not as interpretable as those of decision trees. In many applications, it is desirable to extract knowledge from trained neural networks so that the users can...

  5. Feature Weight Tuning for Recursive Neural Networks

    OpenAIRE

    2014-01-01

    This paper addresses how a recursive neural network model can automatically leave out useless information and emphasize important evidence, in other words, to perform "weight tuning" for higher-level representation acquisition. We propose two models, Weighted Neural Network (WNN) and Binary-Expectation Neural Network (BENN), which automatically control how much one specific unit contributes to the higher-level representation. The proposed model can be viewed as incorporating a more powerful c...

  6. Modelling Microwave Devices Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Andrius Katkevičius

    2012-04-01

    Full Text Available Artificial neural networks (ANN have recently gained attention as fast and flexible equipment for modelling and designing microwave devices. The paper reviews the opportunities to use them for undertaking the tasks on the analysis and synthesis. The article focuses on what tasks might be solved using neural networks, what challenges might rise when using artificial neural networks for carrying out tasks on microwave devices and discusses problem-solving techniques for microwave devices with intermittent characteristics.Article in Lithuanian

  7. Fast Algorithms for Convolutional Neural Networks

    OpenAIRE

    Lavin, Andrew; Gray, Scott

    2015-01-01

    Deep convolutional neural networks take GPU days of compute time to train on large data sets. Pedestrian detection for self driving cars requires very low latency. Image recognition for mobile phones is constrained by limited processing resources. The success of convolutional neural networks in these situations is limited by how fast we can compute them. Conventional FFT based convolution is fast for large filters, but state of the art convolutional neural networks use small, 3x3 filters. We ...

  8. Neural crest contributions to the lamprey head

    Science.gov (United States)

    McCauley, David W.; Bronner-Fraser, Marianne

    2003-01-01

    The neural crest is a vertebrate-specific cell population that contributes to the facial skeleton and other derivatives. We have performed focal DiI injection into the cranial neural tube of the developing lamprey in order to follow the migratory pathways of discrete groups of cells from origin to destination and to compare neural crest migratory pathways in a basal vertebrate to those of gnathostomes. The results show that the general pathways of cranial neural crest migration are conserved throughout the vertebrates, with cells migrating in streams analogous to the mandibular and hyoid streams. Caudal branchial neural crest cells migrate ventrally as a sheet of cells from the hindbrain and super-pharyngeal region of the neural tube and form a cylinder surrounding a core of mesoderm in each pharyngeal arch, similar to that seen in zebrafish and axolotl. In addition to these similarities, we also uncovered important differences. Migration into the presumptive caudal branchial arches of the lamprey involves both rostral and caudal movements of neural crest cells that have not been described in gnathostomes, suggesting that barriers that constrain rostrocaudal movement of cranial neural crest cells may have arisen after the agnathan/gnathostome split. Accordingly, neural crest cells from a single axial level contributed to multiple arches and there was extensive mixing between populations. There was no apparent filling of neural crest derivatives in a ventral-to-dorsal order, as has been observed in higher vertebrates, nor did we find evidence of a neural crest contribution to cranial sensory ganglia. These results suggest that migratory constraints and additional neural crest derivatives arose later in gnathostome evolution.

  9. Semantic Interpretation of An Artificial Neural Network

    Science.gov (United States)

    1995-12-01

    ARTIFICIAL NEURAL NETWORK .7,’ THESIS Stanley Dale Kinderknecht Captain, USAF 770 DEAT7ET77,’H IR O C 7... ARTIFICIAL NEURAL NETWORK THESIS Stanley Dale Kinderknecht Captain, USAF AFIT/GCS/ENG/95D-07 Approved for public release; distribution unlimited The views...Government. AFIT/GCS/ENG/95D-07 SEMANTIC INTERPRETATION OF AN ARTIFICIAL NEURAL NETWORK THESIS Presented to the Faculty of the School of Engineering of

  10. Forecasting Exchange Rate Using Neural Networks

    OpenAIRE

    Raksaseree, Sukhita

    2009-01-01

    The artificial neural network models become increasingly popular among researchers and investors since many studies have shown that it has superior performance over the traditional statistical model. This paper aims to investigate the neural network performance in forecasting foreign exchange rates based on backpropagation algorithm. The forecast of Thai Baht against seven currencies are conducted to observe the performance of the neural network models using the performance criteria for both ...

  11. Adaptive optimization and control using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Mead, W.C.; Brown, S.K.; Jones, R.D.; Bowling, P.S.; Barnes, C.W.

    1993-10-22

    Recent work has demonstrated the ability of neural-network-based controllers to optimize and control machines with complex, non-linear, relatively unknown control spaces. We present a brief overview of neural networks via a taxonomy illustrating some capabilities of different kinds of neural networks. We present some successful control examples, particularly the optimization and control of a small-angle negative ion source.

  12. Introduction to Concepts in Artificial Neural Networks

    Science.gov (United States)

    Niebur, Dagmar

    1995-01-01

    This introduction to artificial neural networks summarizes some basic concepts of computational neuroscience and the resulting models of artificial neurons. The terminology of biological and artificial neurons, biological and machine learning and neural processing is introduced. The concepts of supervised and unsupervised learning are explained with examples from the power system area. Finally, a taxonomy of different types of neurons and different classes of artificial neural networks is presented.

  13. Neural network signal understanding for instrumentation

    DEFF Research Database (Denmark)

    Pau, L. F.; Johansen, F. S.

    1990-01-01

    A report is presented on the use of neural signal interpretation theory and techniques for the purpose of classifying the shapes of a set of instrumentation signals, in order to calibrate devices, diagnose anomalies, generate tuning/settings, and interpret the measurement results. Neural signal......, and an explanation facility designed to help neural signal understanding is described. The results are compared to those obtained with a knowledge-based signal interpretation system using the same instrument and data...

  14. [Histaminergic angioedema and chronic urticaria].

    Science.gov (United States)

    Hacard, Florence; Nosbaum, Audrey; Bensaid, Benoit; Nicolas, Jean-François; Augey, Frédéric; Goujon, Catherine; Bérard, Frédéric

    2015-01-01

    Most angioedemas are histaminergic and correspond to deep urticarial swelling. Recurrent histaminergic angioedema led to the diagnosis of chronic urticaria, even when there are no superficial associated hives. Chronic urticaria is a benign disease, and autoimmune in 40 % of cases. The occurrence of angioedema in chronic urticaria is not a sign of severity. The occurrence of angioedema in chronic urticaria is associated with a longer duration of urticarial disease. NSAIDs and/or systemic corticotherapy are classic triggers of angioedema in chronic urticaria. In the absence of clinical endpoints, there is no need to make further assessment in chronic urticaria good responders to antihistamines.

  15. Initial conditions in the neural field model

    CERN Document Server

    Valdes-Hernandez, Pedro A

    2016-01-01

    In spite of the large amount of existing neural models in the literature, there is a lack of a systematic review of the possible effect of choosing different initial conditions on the dynamic evolution of neural systems. In this short review we intend to give insights into this topic by discussing some published examples. First, we briefly introduce the different ingredients of a neural dynamical model. Secondly, we introduce some concepts used to describe the dynamic behavior of neural models, namely phase space and its portraits, time series, spectra, multistability and bifurcations. We end with an analysis of the irreversibility of processes and its implications on the functioning of normal and pathological brains.

  16. Practical neural network recipies in C++

    CERN Document Server

    Masters

    2014-01-01

    This text serves as a cookbook for neural network solutions to practical problems using C++. It will enable those with moderate programming experience to select a neural network model appropriate to solving a particular problem, and to produce a working program implementing that network. The book provides guidance along the entire problem-solving path, including designing the training set, preprocessing variables, training and validating the network, and evaluating its performance. Though the book is not intended as a general course in neural networks, no background in neural works is assum

  17. NeuroMEMS: Neural Probe Microtechnologies

    Directory of Open Access Journals (Sweden)

    Sam Musallam

    2008-10-01

    Full Text Available Neural probe technologies have already had a significant positive effect on our understanding of the brain by revealing the functioning of networks of biological neurons. Probes are implanted in different areas of the brain to record and/or stimulate specific sites in the brain. Neural probes are currently used in many clinical settings for diagnosis of brain diseases such as seizers, epilepsy, migraine, Alzheimer’s, and dementia. We find these devices assisting paralyzed patients by allowing them to operate computers or robots using their neural activity. In recent years, probe technologies were assisted by rapid advancements in microfabrication and microelectronic technologies and thus are enabling highly functional and robust neural probes which are opening new and exciting avenues in neural sciences and brain machine interfaces. With a wide variety of probes that have been designed, fabricated, and tested to date, this review aims to provide an overview of the advances and recent progress in the microfabrication techniques of neural probes. In addition, we aim to highlight the challenges faced in developing and implementing ultralong multi-site recording probes that are needed to monitor neural activity from deeper regions in the brain. Finally, we review techniques that can improve the biocompatibility of the neural probes to minimize the immune response and encourage neural growth around the electrodes for long term implantation studies.

  18. Fuzzy neural network theory and application

    CERN Document Server

    Liu, Puyin

    2004-01-01

    This book systematically synthesizes research achievements in the field of fuzzy neural networks in recent years. It also provides a comprehensive presentation of the developments in fuzzy neural networks, with regard to theory as well as their application to system modeling and image restoration. Special emphasis is placed on the fundamental concepts and architecture analysis of fuzzy neural networks. The book is unique in treating all kinds of fuzzy neural networks and their learning algorithms and universal approximations, and employing simulation examples which are carefully designed to he

  19. Hydrogel-Electrospun Fiber Mat Composite Coatings for Neural Prostheses

    Directory of Open Access Journals (Sweden)

    Ning eHan

    2011-03-01

    Full Text Available Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron-prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel-electrospun fiber mat (EFM composite coatings. In particular, poly(ethylene glycol-poly(ε-caprolactone (PEGPCL hydrogel- poly(ε-caprolactone (PCL EFM composites were applied as coatings for multielectrode arrays (MEAs. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF, was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel-EFM composite materials can be applied to neural prostheses as a means to improve neuron-electrode proximity and enhance long-term device performance and function.

  20. Chronic obstructive pulmonary disease - adults - discharge

    Science.gov (United States)

    COPD - adults - discharge; Chronic obstructive airways disease - adults - discharge; Chronic obstructive lung disease - adults - discharge; Chronic bronchitis - adults - discharge; Emphysema - adults - discharge; Bronchitis - ...

  1. Functional Magnetic Resonance Imaging of Chronic Dysarthric Speech after Childhood Brain Injury: Reliance on a Left-Hemisphere Compensatory Network

    Science.gov (United States)

    Morgan, Angela T.; Masterton, Richard; Pigdon, Lauren; Connelly, Alan; Liegeois, Frederique J.

    2013-01-01

    Severe and persistent speech disorder, dysarthria, may be present for life after brain injury in childhood, yet the neural correlates of this chronic disorder remain elusive. Although abundant literature is available on language reorganization after lesions in childhood, little is known about the capacity of motor speech networks to reorganize…

  2. Altered functional connectivity of prefrontal cortex in chronic heroin abusers

    Institute of Scientific and Technical Information of China (English)

    Yinbao Qi; Xianming Fu; Ruobing Qian; Chaoshi Niu; Xiangpin Wei

    2011-01-01

    In this study, we investigated alterations in the resting-state functional connectivity of the pre-frontal cortex in chronic heroin abusers using functional magnetic resonance imaging. We found that, compared with normal controls, in heroin abusers the left prefrontal cortex showed decreased functional connectivity with the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus and right precuneus. However, the right prefrontal cortex showed decreased functional connectivity with the left orbital frontal cortex and the left middle frontal gyrus in chronic heroin abusers. These alterations of resting-state functional connectivity in the prefrontal cortices of heroin abusers suggest that their frontal executive neural network may be impaired, and that this may contribute to their continued heroin abuse and relapse after withdrawal.

  3. Chronic pancreatitis in dogs.

    Science.gov (United States)

    Watson, Penny

    2012-08-01

    Chronic pancreatitis used to be considered uncommon in dogs, but recent pathological and clinical studies have confirmed that it is in fact a common and clinically significant disease. Clinical signs can vary from low-grade recurrent gastrointestinal signs to acute exacerbations that are indistinguishable from classical acute pancreatitis. Chronic pancreatitis is a significant cause of chronic pain in dogs, which must not be underestimated. It also results in progressive impairment of endocrine and exocrine function and the eventual development of diabetes mellitus or exocrine pancreatic insufficiency or both in some affected dogs at end stage. The etiology is unknown in most cases. Chronic pancreatitis shows an increased prevalence in certain breeds, and recent work in English Cocker Spaniels suggests it is part of a polysystemic immune-mediated disease in this breed. The histological and clinical appearance is different in different breeds, suggesting that etiologies may also be different. Diagnosis is challenging because the sensitivities of the available noninvasive tests are relatively low. However, with an increased index of suspicion, clinicians will recognize more cases that will allow them to institute supportive treatment to improve the quality of life of the patient.

  4. Acetaminophen for Chronic Pain

    DEFF Research Database (Denmark)

    Ennis, Zandra Nymand; Dideriksen, Dorthe; Vaegter, Henrik Bjarke;

    2016-01-01

    strategies for acetaminophen use in chronic pain in both Embase and PubMed, 1,551 hits were obtained. Following cross-reference searches of both trials and 38 reviews, seven studies comparing acetaminophen in continuous dosing regimens of more than two weeks with placebo were included. The review...

  5. Refractory chronic migraine

    DEFF Research Database (Denmark)

    Martelletti, Paolo; Katsarava, Zaza; Lampl, Christian

    2014-01-01

    The debate on the clinical definition of refractory Chronic Migraine (rCM) is still far to be concluded. The importance to create a clinical framing of these rCM patients resides in the complete disability they show, in the high risk of serious adverse events from acute and preventative drugs...

  6. Diagnosing chronic rhinosinusitis

    DEFF Research Database (Denmark)

    Lange, B; Thilsing, T; Baelum, J;

    2013-01-01

    The European Position Paper on Rhinosinusitis and Nasal Polyps (EP3OS) incorporates symptomatic and endo- scopic criteria in the clinical diagnosis of chronic rhinosinusitis (CRS), while in epidemiological studies the definition is based on symptoms only. The aim of this study was to evaluate the...

  7. Chronic recurrent multifocal osteomyelitis

    NARCIS (Netherlands)

    Wedman, Jan; van Weissenbruch, Ranny

    2005-01-01

    We report what is, to our best knowledge, the first case of chronic recurrent multifocal osteomyelitis (CRMO) in which the frontal and sphenoid bones were involved. Characterized by a prolonged and fluctuating course of osteomyelitis at different sites, CRMO is self-limited, although sequelae can oc

  8. CHRONIC PROBLEM FAMILIES.

    Science.gov (United States)

    STONE, EDWARD

    THE REPORT POINTS OUT THAT, IN GENERAL, CHRONIC PROBLEM PARENTS GREW UP IN ENVIRONMENTS OF EMOTIONAL IMPOVERISHMENT, INCONSISTENCY, CONFUSION, AND DISORDER, OFTEN WITH DEPRIVATION OF FOOD, CLOTHING, AND SHELTER. THESE PARENTS CATEGORIZE PEOPLE AS THOSE WHO GIVE AND THOSE WHO TAKE. THEY BLAME THEIR PROBLEMS ON EXTERNAL CIRCUMSTANCES NOT UNDER THEIR…

  9. Chronic blood pressure control.

    Science.gov (United States)

    Brands, Michael W

    2012-10-01

    Chronic blood pressure is maintained within very narrow limits around an average value. However, the multitude of physiologic processes that participate in blood pressure control present a bewildering array of possibilities to explain how such tight control of arterial pressure is achieved. Guyton and Coleman and colleagues addressed this challenge by creating a mathematical model that integrated the short- and long-term control systems for overall regulation of the circulation. The hub is the renal-body fluid feedback control system, which links cardiac function and vascular resistance and capacitance with fluid volume homeostasis as the foundation for chronic blood pressure control. The cornerstone of that system is renal sodium excretory capability, which is defined by the direct effect of blood pressure on urinary sodium excretion, that is, "pressure natriuresis." Steady-state blood pressure is the pressure at which pressure natriuresis balances sodium intake over time; therefore, renal sodium excretory capability is the set point for chronic blood pressure. However, this often is misinterpreted as dismissing, or minimizing, the importance of nonrenal mechanisms in chronic blood pressure control. This article explains the renal basis for the blood pressure set point by focusing on the absolute dependence of our survival on the maintenance of sodium balance. Two principal threats to sodium balance are discussed: (1) a change in sodium intake or renal excretory capability and (2) a change in blood pressure. In both instances, circulatory homeostasis is maintained because the sodium balance blood pressure set point is reached.

  10. Chronic Kidney Disease

    Science.gov (United States)

    ... of the feet and ankles Causes & Risk FactorsWhat causes CKD?The most common causes of CKD are high blood pressure, diabetes and heart disease. ... caused by CKD.How else is CKD treated?Chronic kidney disease can cause other problems. Talk with your doctor about how ...

  11. EBV CHRONIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    Eligio Pizzigallo

    2010-08-01

    Full Text Available The infection from Epstein-Barr virus (EBV or virus of infectious mononucleosis, together with other herpesviruses’ infections, represents a prototype of persistent viral infections characterized by the property of the latency. Although the reactivations of the latent infection are associated with the resumption of the viral replication and eventually with the “shedding”, it is still not clear if this virus can determine chronic infectious diseases, more or less evolutive. These diseases could include some pathological conditions actually defined as “idiopathic”and characterized by the “viral persistence” as the more credible pathogenetic factor. Among the so-called idiopathic syndromes, the “chronic fatigue syndrome” (CFS aroused a great interest around the eighties of the last century when, just for its relationship with EBV, it was called “chronic mononucleosis” or “chronic EBV infection”. Today CFS, as defined in 1994 by the CDC of Atlanta (USA, really represents a multifactorial syndrome characterized by a chronic course, where reactivation and remission phases alternate, and by a good prognosis. The etiopathogenetic role of EBV is demonstrated only in a well-examined subgroup of patients, while in most of the remaining cases this role should be played by other infectious agents - able to remain in a latent or persistent way in the host – or even by not infectious agents (toxic, neuroendocrine, methabolic, etc.. However, the pathogenetic substrate of the different etiologic forms seems to be the same, much probably represented by the oxidative damage due to the release of pro-inflammatory cytokines as a response to the triggering event (infectious or not infectious. Anyway, recently the scientists turned their’s attention to the genetic predisposition of the subjects affected by the syndrome, so that in the last years the genetic studies, together with those of molecular biology, received a great impulse

  12. Explicit neural representations, recursive neural networks and conscious visual perception.

    Science.gov (United States)

    Pollen, Daniel A

    2003-08-01

    The fundamental question as to whether the neural correlates of any given conscious visual experience are expressed locally within a given cortical area or more globally within some widely distributed network remains unresolved. We inquire as to whether recursive processing-by which we mean the combined flow and integrated outcome of afferent and recurrent activity across a series of cortical areas-is essential for the emergence of conscious visual experience. If so, we further inquire as to whether such recursive processing is essential only for loops between extrastriate cortical areas explicitly representing experiences such as color or motion back to V1 or whether it is processing between still higher levels and the areas computing such explicit representations that is exclusively or additionally essential for visual experience. If recursive processing is not essential for the emergence of conscious visual experience, then it should also be possible to determine whether it is only the intracortical sensory processing within areas computing explicit sensory representations that is required for perceptual experience or whether it is the subsequent processing of the output of such areas within more anterior cortical regions that engenders perception. The present analysis suggests that the questions posed here may ultimately become experimentally resolvable. Whatever the outcome, the results will likely open new approaches to identify the neural correlates of conscious visual perception.

  13. Screening for Chronic Kidney Disease

    Science.gov (United States)

    Understanding Task Force Recommendations Screening for Chronic Kidney Disease The U.S. Preventive Services Task Force (Task Force) has issued a final recommendation on Screening for Chronic Kidney Disease (CKD) . This recommendation ...

  14. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

    Science.gov (United States)

    ... and abnormal sensations. CIDP is closely related to Guillain-Barre syndrome and it is considered the chronic counterpart ... and abnormal sensations. CIDP is closely related to Guillain-Barre syndrome and it is considered the chronic counterpart ...

  15. Chronic Fatigue Syndrome (CFS): Symptoms

    Science.gov (United States)

    ... CDC.gov . Chronic Fatigue Syndrome (CFS) Share Compartir Symptoms On this Page Primary Symptoms Other Symptoms What's ... a doctor distinguish CFS from other illnesses. Primary Symptoms As the name chronic fatigue syndrome suggests , fatigue ...

  16. Optical implementation of neural networks

    Science.gov (United States)

    Yu, Francis T. S.; Guo, Ruyan

    2002-12-01

    An adaptive optical neuro-computing (ONC) using inexpensive pocket size liquid crystal televisions (LCTVs) had been developed by the graduate students in the Electro-Optics Laboratory at The Pennsylvania State University. Although this neuro-computing has only 8×8=64 neurons, it can be easily extended to 16×20=320 neurons. The major advantages of this LCTV architecture as compared with other reported ONCs, are low cost and the flexibility to operate. To test the performance, several neural net models are used. These models are Interpattern Association, Hetero-association and unsupervised learning algorithms. The system design considerations and experimental demonstrations are also included.

  17. Systolic implementation of neural networks

    Energy Technology Data Exchange (ETDEWEB)

    De Groot, A.J.; Parker, S.R.

    1989-01-01

    The backpropagation algorithm for error gradient calculations in multilayer, feed-forward neural networks is derived in matrix form involving inner and outer products. It is demonstrated that these calculations can be carried out efficiently using systolic processing techniques, particularly using the SPRINT, a 64-element systolic processor developed at Lawrence Livermore National Laboratory. This machine contains one million synapses, and forward-propagates 12 million connections per second, using 100 watts of power. When executing the algorithm, each SPRINT processor performs useful work 97% of the time. The theory and applications are confirmed by some nontrivial examples involving seismic signal recognition. 4 refs., 7 figs.

  18. Magnitude Sensitive Competitive Neural Networks

    OpenAIRE

    Pelayo Campillos, Enrique; Buldain Pérez, David; Orrite Uruñuela, Carlos

    2014-01-01

    En esta Tesis se presentan un conjunto de redes neuronales llamadas Magnitude Sensitive Competitive Neural Networks (MSCNNs). Se trata de un conjunto de algoritmos de Competitive Learning que incluyen un término de magnitud como un factor de modulación de la distancia usada en la competición. Al igual que otros métodos competitivos, MSCNNs realizan la cuantización vectorial de los datos, pero el término de magnitud guía el entrenamiento de los centroides de modo que se representan con alto de...

  19. Physical, neural, and mental timing.

    Science.gov (United States)

    van de Grind, Wim

    2002-06-01

    The conclusions drawn by Benjamin Libet from his work with colleagues on the timing of somatosensorial conscious experiences has met with a lot of praise and criticism. In this issue we find three examples of the latter. Here I attempt to place the divide between the two opponent camps in a broader perspective by analyzing the question of the relation between physical timing, neural timing, and experiential (mental) timing. The nervous system does a sophisticated job of recombining and recoding messages from the sensorial surfaces and if these processes are slighted in a theory, it might become necessary to postulate weird operations, including subjective back-referral. Neuroscientifically inspired theories are of necessity still based on guesses, extrapolations, and philosophically dubious manners of speech. They often assume some neural correlate of consciousness (NCC) as a part of the nervous system that transforms neural activity in reportable experiences. The majority of neuroscientists appear to assume that the NCC can compare and bind activity patterns only if they arrive simultaneously at the NCC. This leads to a search for synchrony or to theories in terms of the compensation of differences in neural delays (latencies). This is the main dimension of the Libet discussion. Examples from vision research, such as "temporal-binding-by-synchrony" and the "flash-lag" effect, are then used to illustrate these reasoning patterns in more detail. Alternatively one could assume symbolic representations of time and space (symbolic "tags") that are not coded in their own dimension (not time in time and space in space). Unless such tags are multiplexed with the quality message (tickle, color, or motion), one gets a binding problem for tags. One of the hidden aspects of the discussion between Libet and opponents appears to be the following. Is the NCC smarter than the rest of the nervous system, so that it can solve the problems of local sign (e.g., "where is the event

  20. European Seminar on Neural Computing

    Science.gov (United States)

    1988-08-31

    when McCulloch and Pitts (1943) showed (auto-associator) or a relationship between remembered that networks of neuronlike elements were general com...idea of modeling neurons by threshold automa- ta can be traced back to work done by McCulloch and Artificial Neural Systems Pitts in 1942, according...34The U-Interpreter," IEEE Computer, McCulloch , W.S. and W. Pitts , "A Logical Calculus of the Ideas Immi- Vol. 15, No.2, (February 1982), 42-49. nent in

  1. The LILARTI neural network system

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.D. Jr.; Schell, F.M.; Dodd, C.V.

    1992-10-01

    The material of this Technical Memorandum is intended to provide the reader with conceptual and technical background information on the LILARTI neural network system of detail sufficient to confer an understanding of the LILARTI method as it is presently allied and to facilitate application of the method to problems beyond the scope of this document. Of particular importance in this regard are the descriptive sections and the Appendices which include operating instructions, partial listings of program output and data files, and network construction information.

  2. Chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    V K Vijayan

    2013-01-01

    Full Text Available The global prevalence of physiologically defined chronic obstructive pulmonary disease (COPD in adults aged >40 yr is approximately 9-10 per cent. Recently, the Indian Study on Epidemiology of Asthma, Respiratory Symptoms and Chronic Bronchitis in Adults had shown that the overall prevalence of chronic bronchitis in adults >35 yr is 3.49 per cent. The development of COPD is multifactorial and the risk factors of COPD include genetic and environmental factors. Pathological changes in COPD are observed in central airways, small airways and alveolar space. The proposed pathogenesis of COPD includes proteinase-antiproteinase hypothesis, immunological mechanisms, oxidant-antioxidant balance, systemic inflammation, apoptosis and ineffective repair. Airflow limitation in COPD is defined as a postbronchodilator FEV1 (forced expiratory volume in 1 sec to FVC (forced vital capacity ratio <0.70. COPD is characterized by an accelerated decline in FEV1. Co morbidities associated with COPD are cardiovascular disorders (coronary artery disease and chronic heart failure, hypertension, metabolic diseases (diabetes mellitus, metabolic syndrome and obesity, bone disease (osteoporosis and osteopenia, stroke, lung cancer, cachexia, skeletal muscle weakness, anaemia, depression and cognitive decline. The assessment of COPD is required to determine the severity of the disease, its impact on the health status and the risk of future events (e.g., exacerbations, hospital admissions or death and this is essential to guide therapy. COPD is treated with inhaled bronchodilators, inhaled corticosteroids, oral theophylline and oral phosphodiesterase-4 inhibitor. Non pharmacological treatment of COPD includes smoking cessation, pulmonary rehabilitation and nutritional support. Lung volume reduction surgery and lung transplantation are advised in selected severe patients. Global strategy for the diagnosis, management and prevention of Chronic Obstructive Pulmonary Disease

  3. Defining and Measuring Chronic Conditions

    Centers for Disease Control (CDC) Podcasts

    2013-05-20

    This podcast is an interview with Dr. Anand Parekh, U.S. Department of Health and Human Services Deputy Assistant Secretary for Health, and Dr. Samuel Posner, Preventing Chronic Disease Editor in Chief, about the definition and burden of multiple chronic conditions in the United States.  Created: 5/20/2013 by Preventing Chronic Disease (PCD), National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 5/20/2013.

  4. Dopamine neurons modulate neural encoding and expression of depression-related behaviour.

    Science.gov (United States)

    Tye, Kay M; Mirzabekov, Julie J; Warden, Melissa R; Ferenczi, Emily A; Tsai, Hsing-Chen; Finkelstein, Joel; Kim, Sung-Yon; Adhikari, Avishek; Thompson, Kimberly R; Andalman, Aaron S; Gunaydin, Lisa A; Witten, Ilana B; Deisseroth, Karl

    2013-01-24

    Major depression is characterized by diverse debilitating symptoms that include hopelessness and anhedonia. Dopamine neurons involved in reward and motivation are among many neural populations that have been hypothesized to be relevant, and certain antidepressant treatments, including medications and brain stimulation therapies, can influence the complex dopamine system. Until now it has not been possible to test this hypothesis directly, even in animal models, as existing therapeutic interventions are unable to specifically target dopamine neurons. Here we investigated directly the causal contributions of defined dopamine neurons to multidimensional depression-like phenotypes induced by chronic mild stress, by integrating behavioural, pharmacological, optogenetic and electrophysiological methods in freely moving rodents. We found that bidirectional control (inhibition or excitation) of specified midbrain dopamine neurons immediately and bidirectionally modulates (induces or relieves) multiple independent depression symptoms caused by chronic stress. By probing the circuit implementation of these effects, we observed that optogenetic recruitment of these dopamine neurons potently alters the neural encoding of depression-related behaviours in the downstream nucleus accumbens of freely moving rodents, suggesting that processes affecting depression symptoms may involve alterations in the neural encoding of action in limbic circuitry.

  5. Neural Networks for Non-linear Control

    DEFF Research Database (Denmark)

    Sørensen, O.

    1994-01-01

    This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process.......This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process....

  6. Neural Control of the Immune System

    Science.gov (United States)

    Sundman, Eva; Olofsson, Peder S.

    2014-01-01

    Neural reflexes support homeostasis by modulating the function of organ systems. Recent advances in neuroscience and immunology have revealed that neural reflexes also regulate the immune system. Activation of the vagus nerve modulates leukocyte cytokine production and alleviates experimental shock and autoimmune disease, and recent data have…

  7. Neural Events in the Reinforcement Contingency

    Science.gov (United States)

    Silva, Maria Teresa Araujo; Goncalves, Fabio Leyser; Garcia-Mijares, Miriam

    2007-01-01

    When neural events are analyzed as stimuli and responses, functional relations among them and among overt stimuli and responses can be unveiled. The integration of neuroscience and the experimental analysis of behavior is beginning to provide empirical evidence of involvement of neural events in the three-term contingency relating discriminative…

  8. Windowed active sampling for reliable neural learning

    NARCIS (Netherlands)

    Barakova, E.I; Spaanenburg, L

    1998-01-01

    The composition of the example set has a major impact on the quality of neural learning. The popular approach is focused on extensive pre-processing to bridge the representation gap between process measurement and neural presentation. In contrast, windowed active sampling attempts to solve these pro

  9. Creativity in design and artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Neocleous, C.C.; Esat, I.I. [Brunel Univ. Uxbridge (United Kingdom); Schizas, C.N. [Univ. of Cyprus, Nicosia (Cyprus)

    1996-12-31

    The creativity phase is identified as an integral part of the design phase. The characteristics of creative persons which are relevant to designing artificial neural networks manifesting aspects of creativity, are identified. Based on these identifications, a general framework of artificial neural network characteristics to implement such a goal are proposed.

  10. Identifying Bilingual Semantic Neural Representations across Languages

    Science.gov (United States)

    Buchweitz, Augusto; Shinkareva, Svetlana V.; Mason, Robert A.; Mitchell, Tom M.; Just, Marcel Adam

    2012-01-01

    The goal of the study was to identify the neural representation of a noun's meaning in one language based on the neural representation of that same noun in another language. Machine learning methods were used to train classifiers to identify which individual noun bilingual participants were thinking about in one language based solely on their…

  11. Neural Networks for Dynamic Flight Control

    Science.gov (United States)

    1993-12-01

    uses the Adaline (22) model for development of the neural networks. Neural Graphics and other AFIT applications use a slightly different model. The...primary difference in the Nguyen application is that the Adaline uses the nonlinear function .f(a) = tanh(a) where standard backprop uses the sigmoid

  12. Neural network classification - A Bayesian interpretation

    Science.gov (United States)

    Wan, Eric A.

    1990-01-01

    The relationship between minimizing a mean squared error and finding the optimal Bayesian classifier is reviewed. This provides a theoretical interpretation for the process by which neural networks are used in classification. A number of confidence measures are proposed to evaluate the performance of the neural network classifier within a statistical framework.

  13. Lie Group Techniques for Neural Learning

    Science.gov (United States)

    2005-01-03

    Lie group techniques for Neural Learning Edinburgh June 2004 Elena Celledoni SINTEF Applied Mathematics, IMF-NTNU Lie group techniques for Neural...ORGANIZATION NAME(S) AND ADDRESS(ES) SINTEF Applied Mathematics, IMF-NTNU 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND

  14. Adaptive Neurons For Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1990-01-01

    Training time decreases dramatically. In improved mathematical model of neural-network processor, temperature of neurons (in addition to connection strengths, also called weights, of synapses) varied during supervised-learning phase of operation according to mathematical formalism and not heuristic rule. Evidence that biological neural networks also process information at neuronal level.

  15. Isolated Speech Recognition Using Artificial Neural Networks

    Science.gov (United States)

    2007-11-02

    In this project Artificial Neural Networks are used as research tool to accomplish Automated Speech Recognition of normal speech. A small size...the first stage of this work are satisfactory and thus the application of artificial neural networks in conjunction with cepstral analysis in isolated word recognition holds promise.

  16. NEURAL METHODS FOR THE FINANCIAL PREDICTION

    Directory of Open Access Journals (Sweden)

    Jerzy Balicki

    2016-06-01

    Full Text Available Artificial neural networks can be used to predict share investment on the stock market, assess the reliability of credit client or predicting banking crises. Moreover, this paper discusses the principles of cooperation neural network algorithms with evolutionary method, and support vector machines. In addition, a reference is made to other methods of artificial intelligence, which are used in finance prediction.

  17. Neural constructivism or self-organization?

    NARCIS (Netherlands)

    van der Maas, H.L.J.; Molenaar, P.C.M.

    2000-01-01

    Comments on the article by S. R. Quartz et al (see record 1998-00749-001) which discussed the constructivist perspective of interaction between cognition and neural processes during development and consequences for theories of learning. Three arguments are given to show that neural constructivism la

  18. Learning from large scale neural simulations

    DEFF Research Database (Denmark)

    Serban, Maria

    2017-01-01

    -possibly explanations of neural and cognitive phenomena, or they can be used to test explanatory hypotheses and identify sufficient causal factors in specific neurobiological mechanisms, or yet again they can be deployed exploratorily to evaluate the hierarchy of multiple neural and cognitive models that are put...

  19. Heterogeneous scaffold designs for selective neural regeneration

    NARCIS (Netherlands)

    Wieringa, P.A.

    2014-01-01

    Over the past 5 decades, there has been a drive to apply technology to enhance neural regeneration in order to improve patient recovery after disease or injury. This has evolved into the field of Neural Engineering, with the aim to understand, control and exploit the development and function of neur

  20. Treating Chronic Myeloid Leukemia by Phase

    Science.gov (United States)

    ... Myeloid Leukemia (CML) Treating Chronic Myeloid Leukemia Treating Chronic Myeloid Leukemia by Phase Treatment options for people ... a stem cell donor with matching tissue type. Chronic phase The standard treatment for chronic phase CML ...

  1. A new perspective on behavioral inconsistency and neural noise in aging: Compensatory speeding of neural communication

    Directory of Open Access Journals (Sweden)

    S. Lee Hong

    2012-09-01

    Full Text Available This paper seeks to present a new perspective on the aging brain. Here, we make connections between two key phenomena of brain aging: 1 increased neural noise or random background activity; and 2 slowing of brain activity. Our perspective proposes the possibility that the slowing of neural processing due to decreasing nerve conduction velocities leads to a compensatory speeding of neuron firing rates. These increased firing rates lead to a broader distribution of power in the frequency spectrum of neural oscillations, which we propose, can just as easily be interpreted as neural noise. Compensatory speeding of neural activity, as we present, is constrained by the: A availability of metabolic energy sources; and B competition for frequency bandwidth needed for neural communication. We propose that these constraints lead to the eventual inability to compensate for age-related declines in neural function that are manifested clinically as deficits in cognition, affect, and motor behavior.

  2. Artificial neural networks in neurosurgery.

    Science.gov (United States)

    Azimi, Parisa; Mohammadi, Hasan Reza; Benzel, Edward C; Shahzadi, Sohrab; Azhari, Shirzad; Montazeri, Ali

    2015-03-01

    Artificial neural networks (ANNs) effectively analyze non-linear data sets. The aimed was A review of the relevant published articles that focused on the application of ANNs as a tool for assisting clinical decision-making in neurosurgery. A literature review of all full publications in English biomedical journals (1993-2013) was undertaken. The strategy included a combination of key words 'artificial neural networks', 'prognostic', 'brain', 'tumor tracking', 'head', 'tumor', 'spine', 'classification' and 'back pain' in the title and abstract of the manuscripts using the PubMed search engine. The major findings are summarized, with a focus on the application of ANNs for diagnostic and prognostic purposes. Finally, the future of ANNs in neurosurgery is explored. A total of 1093 citations were identified and screened. In all, 57 citations were found to be relevant. Of these, 50 articles were eligible for inclusion in this review. The synthesis of the data showed several applications of ANN in neurosurgery, including: (1) diagnosis and assessment of disease progression in low back pain, brain tumours and primary epilepsy; (2) enhancing clinically relevant information extraction from radiographic images, intracranial pressure processing, low back pain and real-time tumour tracking; (3) outcome prediction in epilepsy, brain metastases, lumbar spinal stenosis, lumbar disc herniation, childhood hydrocephalus, trauma mortality, and the occurrence of symptomatic cerebral vasospasm in patients with aneurysmal subarachnoid haemorrhage; (4) the use in the biomechanical assessments of spinal disease. ANNs can be effectively employed for diagnosis, prognosis and outcome prediction in neurosurgery.

  3. Imaging Posture Veils Neural Signals

    Directory of Open Access Journals (Sweden)

    Robert T Thibault

    2016-10-01

    Full Text Available Whereas modern brain imaging often demands holding body positions incongruent with everyday life, posture governs both neural activity and cognitive performance. Humans commonly perform while upright; yet, many neuroimaging methodologies require participants to remain motionless and adhere to non-ecological comportments within a confined space. This inconsistency between ecological postures and imaging constraints undermines the transferability and generalizability of many a neuroimaging assay.Here we highlight the influence of posture on brain function and behavior. Specifically, we challenge the tacit assumption that brain processes and cognitive performance are comparable across a spectrum of positions. We provide an integrative synthesis regarding the increasingly prominent influence of imaging postures on autonomic function, mental capacity, sensory thresholds, and neural activity. Arguing that neuroimagers and cognitive scientists could benefit from considering the influence posture wields on both general functioning and brain activity, we examine existing imaging technologies and the potential of portable and versatile imaging devices (e.g., functional near infrared spectroscopy. Finally, we discuss ways that accounting for posture may help unveil the complex brain processes of everyday cognition.

  4. Neural network modeling of emotion

    Science.gov (United States)

    Levine, Daniel S.

    2007-03-01

    This article reviews the history and development of computational neural network modeling of cognitive and behavioral processes that involve emotion. The exposition starts with models of classical conditioning dating from the early 1970s. Then it proceeds toward models of interactions between emotion and attention. Then models of emotional influences on decision making are reviewed, including some speculative (not and not yet simulated) models of the evolution of decision rules. Through the late 1980s, the neural networks developed to model emotional processes were mainly embodiments of significant functional principles motivated by psychological data. In the last two decades, network models of these processes have become much more detailed in their incorporation of known physiological properties of specific brain regions, while preserving many of the psychological principles from the earlier models. Most network models of emotional processes so far have dealt with positive and negative emotion in general, rather than specific emotions such as fear, joy, sadness, and anger. But a later section of this article reviews a few models relevant to specific emotions: one family of models of auditory fear conditioning in rats, and one model of induced pleasure enhancing creativity in humans. Then models of emotional disorders are reviewed. The article concludes with philosophical statements about the essential contributions of emotion to intelligent behavior and the importance of quantitative theories and models to the interdisciplinary enterprise of understanding the interactions of emotion, cognition, and behavior.

  5. Neural locus of color afterimages.

    Science.gov (United States)

    Zaidi, Qasim; Ennis, Robert; Cao, Dingcai; Lee, Barry

    2012-02-07

    After fixating on a colored pattern, observers see a similar pattern in complementary colors when the stimulus is removed [1-6]. Afterimages were important in disproving the theory that visual rays emanate from the eye, in demonstrating interocular interactions, and in revealing the independence of binocular vision from eye movements. Afterimages also prove invaluable in exploring selective attention, filling in, and consciousness. Proposed physiological mechanisms for color afterimages range from bleaching of cone photopigments to cortical adaptation [4-9], but direct neural measurements have not been reported. We introduce a time-varying method for evoking afterimages, which provides precise measurements of adaptation and a direct link between visual percepts and neural responses [10]. We then use in vivo electrophysiological recordings to show that all three classes of primate retinal ganglion cells exhibit subtractive adaptation to prolonged stimuli, with much slower time constants than those expected of photoreceptors. At the cessation of the stimulus, ganglion cells generate rebound responses that can provide afterimage signals for later neurons. Our results indicate that afterimage signals are generated in the retina but may be modified like other retinal signals by cortical processes, so that evidence presented for cortical generation of color afterimages is explainable by spatiotemporal factors that modify all signals.

  6. Imaging Posture Veils Neural Signals

    Science.gov (United States)

    Thibault, Robert T.; Raz, Amir

    2016-01-01

    Whereas modern brain imaging often demands holding body positions incongruent with everyday life, posture governs both neural activity and cognitive performance. Humans commonly perform while upright; yet, many neuroimaging methodologies require participants to remain motionless and adhere to non-ecological comportments within a confined space. This inconsistency between ecological postures and imaging constraints undermines the transferability and generalizability of many a neuroimaging assay. Here we highlight the influence of posture on brain function and behavior. Specifically, we challenge the tacit assumption that brain processes and cognitive performance are comparable across a spectrum of positions. We provide an integrative synthesis regarding the increasingly prominent influence of imaging postures on autonomic function, mental capacity, sensory thresholds, and neural activity. Arguing that neuroimagers and cognitive scientists could benefit from considering the influence posture wields on both general functioning and brain activity, we examine existing imaging technologies and the potential of portable and versatile imaging devices (e.g., functional near infrared spectroscopy). Finally, we discuss ways that accounting for posture may help unveil the complex brain processes of everyday cognition.

  7. Neural Networks for Emotion Classification

    CERN Document Server

    Sun, Yafei

    2011-01-01

    It is argued that for the computer to be able to interact with humans, it needs to have the communication skills of humans. One of these skills is the ability to understand the emotional state of the person. This thesis describes a neural network-based approach for emotion classification. We learn a classifier that can recognize six basic emotions with an average accuracy of 77% over the Cohn-Kanade database. The novelty of this work is that instead of empirically selecting the parameters of the neural network, i.e. the learning rate, activation function parameter, momentum number, the number of nodes in one layer, etc. we developed a strategy that can automatically select comparatively better combination of these parameters. We also introduce another way to perform back propagation. Instead of using the partial differential of the error function, we use optimal algorithm; namely Powell's direction set to minimize the error function. We were also interested in construction an authentic emotion databases. This...

  8. Paraoxon and Pyridostigmine Interfere with Neural Stem Cell Differentiation

    Science.gov (United States)

    Berríos, Verónica O.; Boukli, Nawal M.; Rodriguez, Jose W.; Negraes, Priscilla D.; Schwindt, Telma T.; Trujillo, Cleber A.; Oliveira, Sophia L. B.; Cubano, Luis A.; Ferchmin, P. A.; Eterovic, Vesna A.; Ulrich, Henning; Martins, Antonio H.

    2015-01-01

    Acetylcholinesterase (AChE) inhibition has been described as the main mechanism of organophosphate (OP)-evoked toxicity. OPs represent a human health threat, because chronic exposure to low doses can damage the developing brain, and acute exposure can produce long-lasting damage to adult brains, despite post-exposure medical countermeasures. Although the main mechanism of OP toxicity is AChE inhibition, several lines of evidence suggest that OPs also act by other mechanisms. We hypothesized that rat neural progenitor cells extracted on embryonic day 14.5 would be affected by constant inhibition of AChE from chronic exposure to OP or pyri-dostigmine (a reversible AChE blocker) during differentiation. In this work, the OP paraoxon decreased cell viability in concentrations >50 μM, as measured with the MTT assay; however, this effect was not dose-dependent. Reduced viability could not be attributed to blockade of AChE activity, since treatment with 200 μM pyri-dostigmine did not affect cell viability, even after 6 days. Although changes in protein expression patterns were noted in both treatments, the distribution of differentiated phenotypes, such as the percentages of neurons and glial cells, was not altered, as determined by flow cytometry. Since paraoxon and pyridostigmine each decreased neurite outgrowth (but did not prevent differentiation), we infer that developmental patterns may have been affected. PMID:25758980

  9. A Neural Model of Mind Wandering.

    Science.gov (United States)

    Mittner, Matthias; Hawkins, Guy E; Boekel, Wouter; Forstmann, Birte U

    2016-08-01

    The role of the default-mode network (DMN) in the emergence of mind wandering and task-unrelated thought has been studied extensively. In parallel work, mind wandering has been associated with neuromodulation via the locus coeruleus (LC) norepinephrine (LC-NE) system. Here we propose a neural model that links the two systems in an integrative framework. The model attempts to explain how dynamic changes in brain systems give rise to the subjective experience of mind wandering. The model implies a neural and conceptual distinction between an off-focus state and an active mind-wandering state and provides a potential neural grounding for well-known cognitive theories of mind wandering. Finally, the proposed neural model of mind wandering generates precise, testable predictions at neural and behavioral levels.

  10. Reading and writing the neural code.

    Science.gov (United States)

    Stanley, Garrett B

    2013-03-01

    It has been more than 20 years since Bialek and colleagues published a landmark paper asking a seemingly innocuous question: what can we extract about the outside world from the spiking activity of sensory neurons? Can we read the neural code? Although this seemingly simple question has helped us shed light on the neural code, we still do not understand the anatomical and neurophysiological constraints that enable these codes to propagate across synapses and form the basis for computations that we need to interact with our environment. The sensitivity of neuronal activity to the timing of synaptic inputs naturally suggests that synchrony determines the form of the neural code, and, in turn, regulation of synchrony is a critical element in 'writing' the neural code through the artificial control of microcircuits to activate downstream structures. In this way, reading and writing the neural code are inextricably linked.

  11. International Conference on Artificial Neural Networks (ICANN)

    CERN Document Server

    Mladenov, Valeri; Kasabov, Nikola; Artificial Neural Networks : Methods and Applications in Bio-/Neuroinformatics

    2015-01-01

    The book reports on the latest theories on artificial neural networks, with a special emphasis on bio-neuroinformatics methods. It includes twenty-three papers selected from among the best contributions on bio-neuroinformatics-related issues, which were presented at the International Conference on Artificial Neural Networks, held in Sofia, Bulgaria, on September 10-13, 2013 (ICANN 2013). The book covers a broad range of topics concerning the theory and applications of artificial neural networks, including recurrent neural networks, super-Turing computation and reservoir computing, double-layer vector perceptrons, nonnegative matrix factorization, bio-inspired models of cell communities, Gestalt laws, embodied theory of language understanding, saccadic gaze shifts and memory formation, and new training algorithms for Deep Boltzmann Machines, as well as dynamic neural networks and kernel machines. It also reports on new approaches to reinforcement learning, optimal control of discrete time-delay systems, new al...

  12. Neural networks with discontinuous/impact activations

    CERN Document Server

    Akhmet, Marat

    2014-01-01

    This book presents as its main subject new models in mathematical neuroscience. A wide range of neural networks models with discontinuities are discussed, including impulsive differential equations, differential equations with piecewise constant arguments, and models of mixed type. These models involve discontinuities, which are natural because huge velocities and short distances are usually observed in devices modeling the networks. A discussion of the models, appropriate for the proposed applications, is also provided. This book also: Explores questions related to the biological underpinning for models of neural networks\\ Considers neural networks modeling using differential equations with impulsive and piecewise constant argument discontinuities Provides all necessary mathematical basics for application to the theory of neural networks Neural Networks with Discontinuous/Impact Activations is an ideal book for researchers and professionals in the field of engineering mathematics that have an interest in app...

  13. Neural network for sonogram gap filling

    DEFF Research Database (Denmark)

    Klebæk, Henrik; Jensen, Jørgen Arendt; Hansen, Lars Kai

    1995-01-01

    a neural network for predicting mean frequency of the velocity signal and its variance. The neural network then predicts the evolution of the mean and variance in the gaps, and the sonogram and audio signal are reconstructed from these. The technique is applied on in-vivo data from the carotid artery....... The neural network is trained on part of the data and the network is pruned by the optimal brain damage procedure in order to reduce the number of parameters in the network, and thereby reduce the risk of overfitting. The neural predictor is compared to using a linear filter for the mean and variance time...... series, and is shown to yield better results, i.e., the variances of the predictions are lower. The ability of the neural predictor to reconstruct both the sonogram and the audio signal, when only 50% of the time is used for velocity data acquisition, is demonstrated for the in-vivo data...

  14. Neural Networks for Rapid Design and Analysis

    Science.gov (United States)

    Sparks, Dean W., Jr.; Maghami, Peiman G.

    1998-01-01

    Artificial neural networks have been employed for rapid and efficient dynamics and control analysis of flexible systems. Specifically, feedforward neural networks are designed to approximate nonlinear dynamic components over prescribed input ranges, and are used in simulations as a means to speed up the overall time response analysis process. To capture the recursive nature of dynamic components with artificial neural networks, recurrent networks, which use state feedback with the appropriate number of time delays, as inputs to the networks, are employed. Once properly trained, neural networks can give very good approximations to nonlinear dynamic components, and by their judicious use in simulations, allow the analyst the potential to speed up the analysis process considerably. To illustrate this potential speed up, an existing simulation model of a spacecraft reaction wheel system is executed, first conventionally, and then with an artificial neural network in place.

  15. Decentralized neural control application to robotics

    CERN Document Server

    Garcia-Hernandez, Ramon; Sanchez, Edgar N; Alanis, Alma y; Ruz-Hernandez, Jose A

    2017-01-01

    This book provides a decentralized approach for the identification and control of robotics systems. It also presents recent research in decentralized neural control and includes applications to robotics. Decentralized control is free from difficulties due to complexity in design, debugging, data gathering and storage requirements, making it preferable for interconnected systems. Furthermore, as opposed to the centralized approach, it can be implemented with parallel processors. This approach deals with four decentralized control schemes, which are able to identify the robot dynamics. The training of each neural network is performed on-line using an extended Kalman filter (EKF). The first indirect decentralized control scheme applies the discrete-time block control approach, to formulate a nonlinear sliding manifold. The second direct decentralized neural control scheme is based on the backstepping technique, approximated by a high order neural network. The third control scheme applies a decentralized neural i...

  16. Video Traffic Prediction Using Neural Networks

    Directory of Open Access Journals (Sweden)

    Miloš Oravec

    2008-10-01

    Full Text Available In this paper, we consider video stream prediction for application in services likevideo-on-demand, videoconferencing, video broadcasting, etc. The aim is to predict thevideo stream for an efficient bandwidth allocation of the video signal. Efficient predictionof traffic generated by multimedia sources is an important part of traffic and congestioncontrol procedures at the network edges. As a tool for the prediction, we use neuralnetworks – multilayer perceptron (MLP, radial basis function networks (RBF networksand backpropagation through time (BPTT neural networks. At first, we briefly introducetheoretical background of neural networks, the prediction methods and the differencebetween them. We propose also video time-series processing using moving averages.Simulation results for each type of neural network together with final comparisons arepresented. For comparison purposes, also conventional (non-neural prediction isincluded. The purpose of our work is to construct suitable neural networks for variable bitrate video prediction and evaluate them. We use video traces from [1].

  17. 22nd Italian Workshop on Neural Nets

    CERN Document Server

    Bassis, Simone; Esposito, Anna; Morabito, Francesco

    2013-01-01

    This volume collects a selection of contributions which has been presented at the 22nd Italian Workshop on Neural Networks, the yearly meeting of the Italian Society for Neural Networks (SIREN). The conference was held in Italy, Vietri sul Mare (Salerno), during May 17-19, 2012. The annual meeting of SIREN is sponsored by International Neural Network Society (INNS), European Neural Network Society (ENNS) and IEEE Computational Intelligence Society (CIS). The book – as well as the workshop-  is organized in three main components, two special sessions and a group of regular sessions featuring different aspects and point of views of artificial neural networks and natural intelligence, also including applications of present compelling interest.

  18. Neural scaling laws for an uncertain world

    CERN Document Server

    Howard, Marc W

    2016-01-01

    The Weber-Fechner law describes the form of psychological space in many behavioral experiments involving perception of one-dimensional physical quantities. If the physical quantity is expressed using multiple neural receptors, then placing receptive fields evenly along a logarithmic scale naturally leads to the psychological Weber-Fechner law. In the visual system, the spacing and width of extrafoveal receptive fields are consistent with logarithmic scaling. Other sets of neural "receptors" appear to show the same qualitative properties, suggesting that this form of neural scaling reflects a solution to a very general problem. This paper argues that these neural scaling laws enable the brain to represent information about the world efficiently without making any assumptions about the statistics of the world. This analysis suggests that the organization of neural scales to represent one-dimensional quantities, including more abstract quantities such as numerosity, time, and allocentric space, should have a uni...

  19. Nonlinear System Control Using Neural Networks

    Directory of Open Access Journals (Sweden)

    Jaroslava Žilková

    2006-10-01

    Full Text Available The paper is focused especially on presenting possibilities of applying off-linetrained artificial neural networks at creating the system inverse models that are used atdesigning control algorithm for non-linear dynamic system. The ability of cascadefeedforward neural networks to model arbitrary non-linear functions and their inverses isexploited. This paper presents a quasi-inverse neural model, which works as a speedcontroller of an induction motor. The neural speed controller consists of two cascadefeedforward neural networks subsystems. The first subsystem provides desired statorcurrent components for control algorithm and the second subsystem providescorresponding voltage components for PWM converter. The availability of the proposedcontroller is verified through the MATLAB simulation. The effectiveness of the controller isdemonstrated for different operating conditions of the drive system.

  20. Neural inhibition enables selection during language processing.

    Science.gov (United States)

    Snyder, Hannah R; Hutchison, Natalie; Nyhus, Erika; Curran, Tim; Banich, Marie T; O'Reilly, Randall C; Munakata, Yuko

    2010-09-21

    Whether grocery shopping or choosing words to express a thought, selecting between options can be challenging, especially for people with anxiety. We investigate the neural mechanisms supporting selection during language processing and its breakdown in anxiety. Our neural network simulations demonstrate a critical role for competitive, inhibitory dynamics supported by GABAergic interneurons. As predicted by our model, we find that anxiety (associated with reduced neural inhibition) impairs selection among options and associated prefrontal cortical activity, even in a simple, nonaffective verb-generation task, and the GABA agonist midazolam (which increases neural inhibition) improves selection, whereas retrieval from semantic memory is unaffected when selection demands are low. Neural inhibition is key to choosing our words.

  1. A new formulation for feedforward neural networks.

    Science.gov (United States)

    Razavi, Saman; Tolson, Bryan A

    2011-10-01

    Feedforward neural network is one of the most commonly used function approximation techniques and has been applied to a wide variety of problems arising from various disciplines. However, neural networks are black-box models having multiple challenges/difficulties associated with training and generalization. This paper initially looks into the internal behavior of neural networks and develops a detailed interpretation of the neural network functional geometry. Based on this geometrical interpretation, a new set of variables describing neural networks is proposed as a more effective and geometrically interpretable alternative to the traditional set of network weights and biases. Then, this paper develops a new formulation for neural networks with respect to the newly defined variables; this reformulated neural network (ReNN) is equivalent to the common feedforward neural network but has a less complex error response surface. To demonstrate the learning ability of ReNN, in this paper, two training methods involving a derivative-based (a variation of backpropagation) and a derivative-free optimization algorithms are employed. Moreover, a new measure of regularization on the basis of the developed geometrical interpretation is proposed to evaluate and improve the generalization ability of neural networks. The value of the proposed geometrical interpretation, the ReNN approach, and the new regularization measure are demonstrated across multiple test problems. Results show that ReNN can be trained more effectively and efficiently compared to the common neural networks and the proposed regularization measure is an effective indicator of how a network would perform in terms of generalization.

  2. [Chronic inflammatory demyelinating polyradiculoneuropathy].

    Science.gov (United States)

    Franques, J; Azulay, J-P; Pouget, J; Attarian, S

    2010-06-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a demyelinating chronic neuropathy of immune origin whose diagnosis is based upon clinical, biological and electrophysiological data; previously critical to the diagnosis the nerve biopsy is now restricted to the rare situations where accurate diagnosis cannot be reached using these data alone. CIDP are mainly idiopathic, but a few associated diseases must be sought for as they require specific attention. Such associated diseases must particularly be discussed when the manifestations are severe or resistant to immunomodulating or immunosuppressive agents. Indeed, idiopathic CIDP are usually responsive to these treatments. The effectiveness of these treatments is limited by the importance of the secondary axonal loss. The dependence or the resistance may sometimes justify the association of several immunomodulating treatments. A single randomized controlled trial support the use of cytotoxic drugs and none with rituximab.

  3. Chronic intestinal pseudoobstruction syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yeon, Kyung Mo; Seo, Jeong Kee; Lee, Yong Seok [Seoul National University Children' s Hospital, Seoul (Korea, Republic of)

    1992-03-15

    Chronic intestinal pseudoobstruction syndrome is a rare clinical condition in which impaired intestinal peristalsis causes recurrent symptoms of bowel obstruction in the absence of a mechanical occlusion. This syndrome may involve variable segments of small or large bowel, and may be associated with urinary bladder retention. This study included 6 children(3 boys and 3 girls) of chronic intestinal obstruction. Four were symptomatic at birth and two were of the ages of one month and one year. All had abdominal distension and deflection difficulty. Five had urinary bladder distension. Despite parenteral nutrition and surgical intervention(ileostomy or colostomy), bowel obstruction persisted and four patients expired from sepses within one year. All had gaseous distension of small and large bowel on abdominal films. In small bowel series, consistent findings were variable degree of dilatation, decreased peristalsis(prolonged transit time) and microcolon or microrectum. This disease entity must be differentiated from congenital megacolon, ileal atresia and megacystis syndrome.

  4. Bilateral chronic subdural hematoma

    DEFF Research Database (Denmark)

    Andersen-Ranberg, Nina Christine; Poulsen, Frantz Rom; Bergholt, Bo

    2017-01-01

    OBJECTIVE Bilateral chronic subdural hematoma (bCSDH) is a common neurosurgical condition frequently associated with the need for retreatment. The reason for the high rate of retreatment has not been thoroughly investigated. Thus, the authors focused on determining which independent predictors...... are associated with the retreatment of bCSDH with a focus on surgical laterality. METHODS In a national database of CSDHs (Danish Chronic Subdural Hematoma Study) the authors retrospectively identified all bCSDHs treated in the 4 Danish neurosurgical departments over the 3-year period from 2010 to 2012....... Univariate and multivariate analyses were performed to determine the relationship between retreatment of bCSDH and clinical, radiological, and surgical variables. RESULTS Two hundred ninety-one patients with bCSDH were identified, and 264 of them underwent unilateral (136 patients) or bilateral (128 patients...

  5. IBIC characterization of an ion-beam-micromachined multi-electrode diamond detector

    CERN Document Server

    Forneris, J; Jaksic, M; Giudice, A Lo; Olivero, P; Picollo, F; Skukan, N; Verona, C; Verona-Rinati, G; Vittone, E

    2016-01-01

    Deep Ion Beam Lithography (DIBL) has been used for the direct writing of buried graphitic regions in monocrystalline diamond with micrometric resolution. Aiming at the development and the characterization of a fully ion-beam-micromachined solid state ionization chamber, a device with interdigitated electrodes was fabricated by using a 1.8 MeV He+ ion microbeam scanning on a homoepitaxial, grown by chemical vapour deposition (CVD). In order to evaluate the ionizing-radiation-detection performance of the device, charge collection efficiency (CCE) maps were extracted from Ion Beam Induced Charge (IBIC) measurements carried out by probing different arrangements of buried microelectrodes. The analysis of the CCE maps allowed for an exhaustive evaluation of the detector features, in particular the individuation of the different role played by electrons and holes in the formation of the induced charge pulses. Finally, a comparison of the performances of the detector with buried graphitic electrodes with those releva...

  6. Development of MATLAB software to control data acquisition from a multichannel systems multi-electrode array.

    Science.gov (United States)

    Messier, Erik

    2016-08-01

    A Multichannel Systems (MCS) microelectrode array data acquisition (DAQ) unit is used to collect multichannel electrograms (EGM) from a Langendorff perfused rabbit heart system to study sudden cardiac death (SCD). MCS provides software through which data being processed by the DAQ unit can be displayed and saved, but this software's combined utility with MATLAB is not very effective. MCSs software stores recorded EGM data in a MathCad (MCD) format, which is then converted to a text file format. These text files are very large, and it is therefore very time consuming to import the EGM data into MATLAB for real-time analysis. Therefore, customized MATLAB software was developed to control the acquisition of data from the MCS DAQ unit, and provide specific laboratory accommodations for this study of SCD. The developed DAQ unit control software will be able to accurately: provide real time display of EGM signals; record and save EGM signals in MATLAB in a desired format; and produce real time analysis of the EGM signals; all through an intuitive GUI.

  7. IBIC characterization of an ion-beam-micromachined multi-electrode diamond detector

    Energy Technology Data Exchange (ETDEWEB)

    Forneris, J., E-mail: forneris@to.infn.it [Università di Torino, Dipartimento di Fisica e Centro di Eccellenza NIS, INFN, sez. Torino, CNISM, sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Grilj, V.; Jakšić, M. [Ruđer Bošković Institute, Bijenička cesta 54, P.O. Box 180, 10002 Zagreb (Croatia); Lo Giudice, A.; Olivero, P.; Picollo, F. [Università di Torino, Dipartimento di Fisica e Centro di Eccellenza NIS, INFN, sez. Torino, CNISM, sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Skukan, N. [Ruđer Bošković Institute, Bijenička cesta 54, P.O. Box 180, 10002 Zagreb (Croatia); Verona, C.; Verona-Rinati, G. [Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, 00133 Roma (Italy); Vittone, E. [Università di Torino, Dipartimento di Fisica e Centro di Eccellenza NIS, INFN, sez. Torino, CNISM, sez. Torino, via P. Giuria 1, 10125 Torino (Italy)

    2013-07-01

    Deep Ion Beam Lithography (DIBL) has been used for the direct writing of buried graphitic regions in monocrystalline diamond with micrometric resolution. As part of the development and the characterization of a fully ion-beam-micromachined solid-state ionization chamber, a device with interdigitated electrodes was fabricated by using a 1.8 MeV He{sup +} ion microbeam, which scanned a 40 μm thick homoepitaxial detector grade diamond sample grown by chemical vapor deposition (CVD). In order to evaluate the ionizing-radiation-detection performance of the device, charge collection efficiency (CCE) maps were extracted from Ion Beam Induced Charge (IBIC) measurements carried out by probing different arrangements of buried micro-electrodes. The analysis of the CCE maps allowed an exhaustive evaluation of the detector features, in particular the individuation of the different role played by electrons and holes in the formation of the induced charge pulses. Finally, a comparison of the performances of the detector with buried graphitic electrodes with those relevant to conventional metallic surface electrodes evidenced the formation of a dead layer overlying the buried electrodes as a result of the fabrication process.

  8. Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate

    KAUST Repository

    Rader, Geoffrey K.

    2010-09-01

    Most microbial electrolysis cells (MECs) contain only a single set of electrodes. In order to examine the scalability of a multiple-electrode design, we constructed a 2.5 L MEC containing 8 separate electrode pairs made of graphite fiber brush anodes pre-acclimated for current generation using acetate, and 304 stainless steel mesh cathodes (64 m2/m3). Under continuous flow conditions and a one day hydraulic retention time, the maximum current was 181 mA (1.18 A/m2, cathode surface area; 74 A/m 3) within three days of operation. The maximum hydrogen production (day 3) was 0.53 L/L-d, reaching an energy efficiency relative to electrical energy input of ηE = 144%. Current production remained relatively steady (days 3-18), but the gas composition dramatically shifted over time. By day 16, there was little H2 gas recovered and methane production increased from 0.049 L/L-d (day 3) to 0.118 L/L-d. When considering the energy value of both hydrogen and methane, efficiency relative to electrical input remained above 100% until near the end of the experiment (day 17) when only methane gas was being produced. Our results show that MECs can be scaled up primarily based on cathode surface area, but that hydrogen can be completely consumed in a continuous flow system unless methanogens can be completely eliminated from the system. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

  9. Firing patterns of long-term cultured neuronal network on multi-electrode array

    Institute of Scientific and Technical Information of China (English)

    LI Xiangning; ZHOU Wei; LIU Man; ZENG Shaoqun; LUO Qingming

    2006-01-01

    Spontaneous neuronal activity plays an important role in the development and plasticity of brain. To explore the developmental changes in the firing pattern of the neuronal networks in vitro, the hippocampal neurons were cultured on the multi-microelectrode array dish for over 14 weeks and the spontaneous activity was recorded. The results showed that random firing was observed in the 1st week and transformed into synchronized activity after two weeks, then tightly synchronized activity appeared in week 2 to 7 and finally the activities transformed into the random firing pattern. These results suggested three stages in the long-term development of neuronal network in vitro: the stage for connection, the stage of synchronized activity and the mature stage. Synchronized firing shown by spontaneous activity was an important phenomenon in high density cultured neuronal network and transformed patterns during development.

  10. Selective in situ potential-assisted SAM formation on multi electrode arrays

    Science.gov (United States)

    Haag, Ann-Lauriene; Toader, Violeta; Lennox, R. Bruce; Grutter, Peter

    2016-11-01

    The selective modification of individual components in a biosensor array is challenging. To address this challenge, we present a generalizable approach to selectively modify and characterize individual gold surfaces in an array, in an in situ manner. This is achieved by taking advantage of the potential dependent adsorption/desorption of surface-modified organic molecules. Control of the applied potential of the individual sensors in an array where each acts as a working electrode provides differential derivatization of the sensor surfaces. To demonstrate this concept, two different self-assembled monolayer (SAM)-forming electrochemically addressable ω-ferrocenyl alkanethiols (C11) are chemisorbed onto independent but spatially adjacent gold electrodes. The ferrocene alkanethiol does not chemisorb onto the surface when the applied potential is cathodic relative to the adsorption potential and the electrode remains underivatized. However, applying potentials that are modestly positive relative to the adsorption potential leads to extensive coverage within 10 min. The resulting SAM remains in a stable state while held at potentials <200 mV above the adsorption potential. In this state, the chemisorbed SAM does not significantly desorb nor do new ferrocenylalkythiols adsorb. Using three set applied potentials provides for controlled submonolayer alkylthiol marker coverage of each independent gold electrode. These three applied potentials are dependent upon the specifics of the respective adsorbate. Characterization of the ferrocene-modified electrodes via cyclic voltammetry demonstrates that each specific ferrocene marker is exclusively adsorbed to the desired target electrode.

  11. USE OF COUPLED MULTI-ELECTRODE ARRAYS TO ADVANCE THE UNDERSTANDING OF SELECTED CORROSION PHENOMENA

    Energy Technology Data Exchange (ETDEWEB)

    N.D. Budiansky; F. Bocher; H. Cong; M.F. Hurley; J.R. Scully

    2006-02-23

    The use of multi-coupled electrode arrays in various corrosion applications is discussed with the main goal of advancing the understanding of various corrosion phenomena. Both close packed and far spaced electrode configurations are discussed. Far spaced electrode arrays are optimized for high throughput experiments capable of elucidating the effects of various variables on corrosion properties. For instance the effects of a statistical distribution of flaws on corrosion properties can be examined. Close packed arrays enable unprecedented spatial and temporal information on the behavior of local anodes and cathodes. Interactions between corrosion sites can trigger or inhibit corrosion phenomena and affect corrosion damage evolution.

  12. Microfluidic in-channel multi-electrode platform for neurotransmitter sensing

    Science.gov (United States)

    Kara, A.; Mathault, J.; Reitz, A.; Boisvert, M.; Tessier, F.; Greener, J.; Miled, A.

    2016-03-01

    In this project we present a microfluidic platform with in-channel micro-electrodes for in situ screening of bio/chemical samples through a lab-on-chip system. We used a novel method to incorporate electrochemical sensors array (16x20) connected to a PCB, which opens the way for imaging applications. A 200 μm height microfluidic channel was bonded to electrochemical sensors. The micro-channel contains 3 inlets used to introduce phosphate buffer saline (PBS), ferrocynide and neurotransmitters. The flow rate was controlled through automated micro-pumps. A multiplexer was used to scan electrodes and perform individual cyclic voltammograms by a custom potentiostat. The behavior of the system was linear in terms of variation of current versus concentration. It was used to detect the neurotransmitters serotonin, dopamine and glutamate.

  13. In vitro simulation of spiral waves in cardiomyocyte networks using multi-electrode array technology

    OpenAIRE

    Jacquir, Sabir; Laurent, Gabriel; Vandroux, David; Binczak, Stéphane; Bilbault, Jean-Marie; Athias, Pierre

    2009-01-01

    International audience; We aimed thus to provide new insights into the cellular origin of the fibrillation phenomenon by exploring the impulse propagation between cardiac myocytes in confluent monolayers of cultured cardiomyocytes (CM),

  14. Flexible multi-electrode array with integrated bendable CMOS-chip for implantable systems.

    Science.gov (United States)

    Winkin, N; Mokwa, W

    2012-01-01

    Micro-electrodes and micro-electrode arrays (MEAs) for stimulating neurons or recording action potentials are widely used in medical applications or biological research. For medical implants in many applications like brain implants or retinal implants there is a need for flexible MEAs with a large area and a large number of stimulation electrodes. In this work a flexible MEA with an embedded flexible silicon dummy CMOS-chip facing these challenges has been designed, manufactured and characterized. This approach offers the possibility by connecting and addressing several of these MEAs via a bus system, to increase the number and the density of electrodes significantly. This paper describes the design and fabrication process. Results on the mechanical and electrical behavior will be given and possible improvements for medical applications by this novel approach will be discussed.

  15. An automated online positioning system and simulation environment for multi-electrodes in extracellular recordings

    DEFF Research Database (Denmark)

    Franke, Felix; Natora, Michal; Meier, Philipp;

    2010-01-01

    Extracellular recordings are a key tool to record the activity of neurons in vivo. Especially in the case of experiments with behaving animals, however, the tedious procedure of electrode placement can take a considerable amount of expensive and restricted experimental time. Furthermore, due to t...

  16. Domestic wastewater treatment using multi-electrode continuous flow MFCs with a separator electrode assembly design

    KAUST Repository

    Ahn, Yongtae

    2012-10-11

    Treatment of domestic wastewater using microbial fuel cells (MFCs) will require reactors with multiple electrodes, but this presents unique challenges under continuous flow conditions due to large changes in the chemical oxygen demand (COD) concentration within the reactor. Domestic wastewater treatment was examined using a single-chamber MFC (130 mL) with multiple graphite fiber brush anodes wired together and a single air cathode (cathode specific area of 27 m2/m3). In fed-batch operation, where the COD concentration was spatially uniform in the reactor but changed over time, the maximum current density was 148 ± 8 mA/m2 (1,000 Ω), the maximum power density was 120 mW/m2, and the overall COD removal was >90 %. However, in continuous flow operation (8 h hydraulic retention time, HRT), there was a 57 % change in the COD concentration across the reactor (influent versus effluent) and the current density was only 20 ± 13 mA/m2. Two approaches were used to increase performance under continuous flow conditions. First, the anodes were separately wired to the cathode, which increased the current density to 55 ± 15 mA/m2. Second, two MFCs were hydraulically connected in series (each with half the original HRT) to avoid large changes in COD among the anodes in the same reactor. The second approach improved current density to 73 ± 13 mA/m2. These results show that current generation from wastewaters in MFCs with multiple anodes, under continuous flow conditions, can be improved using multiple reactors in series, as this minimizes changes in COD in each reactor. © 2012 Springer-Verlag Berlin Heidelberg.

  17. A VLSI Neural Monitoring System With Ultra-Wideband Telemetry for Awake Behaving Subjects.

    Science.gov (United States)

    Greenwald, E; Mollazadeh, M; Hu, C; Wei Tang; Culurciello, E; Thakor, V

    2011-04-01

    Long-term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for neuroscience and neuroengineering applications. Here, we present a miniature, lightweight, and low-power recording system for monitoring neural activity in awake behaving animals. The system integrates two custom designed very-large-scale integrated chips, a neural interface module fabricated in 0.5 μm complementary metal-oxide semiconductor technology and an ultra-wideband transmitter module fabricated in a 0.5 μm silicon-on-sapphire (SOS) technology. The system amplifies, filters, digitizes, and transmits 16 channels of neural data at a rate of 1 Mb/s. The entire system, which includes the VLSI circuits, a digital interface board, a battery, and a custom housing, is small and lightweight (24 g) and, thus, can be chronically mounted on small animals. The system consumes 4.8 mA and records continuously for up to 40 h powered by a 3.7-V, 200-mAh rechargeable lithium-ion battery. Experimental benchtop characterizations as well as in vivo multichannel neural recordings from awake behaving rats are presented here.

  18. Chronic pneumonitis of infancy

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Katsumi; Kamata, Noriko; Okazaki, Eiwa [Department of Radiology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Moriyama, Sachiko; Funata, Nobuaki [Department of Pathology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Takita, Junko; Yamada, Hideo; Takayama, Naohide [Department of Pediatrics, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan)

    2002-07-01

    Chronic pneumonitis of infancy (CPI) is a very rare lung disease in infants and young children. We report a 33-day-old infant with CPI, focusing on the radiologic aspects of the disease. Chest radiographs showed variable and non-specific appearances including ground-glass shadowing, consolidation, volume loss, and hyperinflation. Dense alveolar opacities progressed as CPI advanced. The radiologic features of our case reflected pathologic changes. (orig.)

  19. Renal failure (chronic)

    OpenAIRE

    Clase, Catherine

    2011-01-01

    Chronic renal failure is characterised by a gradual and sustained decline in renal clearance or glomerular filtration rate (GFR). Continued progression of renal failure will lead to renal function too low to sustain healthy life. In developed countries, such people will be offered renal replacement therapy in the form of dialysis or renal transplantation. Requirement for dialysis or transplantation is termed end-stage renal disease (ESRD).Diabetes, glomerulonephritis, hypertension, pyelone...

  20. Chronic Stress and Performance

    Science.gov (United States)

    2011-09-01

    to the cannabinoid CB(1) receptor agonist HU-210 following chronic stress. European Journal of Pharmacology, 499(3), 291-295. Holscher, C. (1999...learning and memory, has the highest concentration of GC receptors in the brain and is involved in the stress response. Extensive research has... receptor levels than stressed male rodents (Konkle, 2003; Figueiredo, 2002; Handa, 1994). Males and females react to stress differently, so two models

  1. EBV CHRONIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    Delia Racciatti

    2010-02-01

    Full Text Available

    The infection from Epstein-Barr virus (EBV or virus of infectious mononucleosis, together with other herpesviruses’ infections, represents a prototype of persistent viral infections characterized by the property of the latency. Although the reactivations of the latent infection are associated with the resumption of the viral replication and eventually with the “shedding”, it is still not clear if this virus can determine chronic infectious diseases, more or less evolutive. These diseases could include some pathological conditions actually defined as “idiopathic”and characterized by the “viral persistence” as the more credible pathogenetic factor. Among the so-called idiopathic syndromes, the “chronic fatigue syndrome” (CFS aroused a great interest around the eighties of the last century when, just for its relationship with EBV, it was called “chronic mononucleosis” or “chronic EBV infection”.

    Today CFS, as defined in 1994 by the CDC of Atlanta (USA, really represents a multifactorial syndrome characterized by a chronic course, where reactivation and remission phases alternate, and by a good prognosis

  2. Chronic arsenic poisoning.

    Science.gov (United States)

    Hall, Alan H

    2002-03-10

    Symptomatic arsenic poisoning is not often seen in occupational exposure settings. Attempted homicide and deliberate long-term poisoning have resulted in chronic toxicity. Skin pigmentation changes, palmar and plantar hyperkeratoses, gastrointestinal symptoms, anemia, and liver disease are common. Noncirrhotic portal hypertension with bleeding esophageal varices, splenomegaly, and hypersplenism may occur. A metallic taste, gastrointestinal disturbances, and Mee's lines may be seen. Bone marrow depression is common. 'Blackfoot disease' has been associated with arsenic-contaminated drinking water in Taiwan; Raynaud's phenomenon and acrocyanosis also may occur. Large numbers of persons in areas of India, Pakistan, and several other countries have been chronically poisoned from naturally occurring arsenic in ground water. Toxic delirium and encephalopathy can be present. CCA-treated wood (chromated copper arsenate) is not a health risk unless burned in fireplaces or woodstoves. Peripheral neuropathy may also occur. Workplace exposure or chronic ingestion of arsenic-contaminated water or arsenical medications is associated with development of skin, lung, and other cancers. Treatment may incklude the use of chelating agents such as dimercaprol (BAL), dimercaptosuccinic acid (DMSA), and dimercaptopanesulfonic acid (DMPS).

  3. EDITORIAL: Special issue on applied neurodynamics: from neural dynamics to neural engineering Special issue on applied neurodynamics: from neural dynamics to neural engineering

    Science.gov (United States)

    Chiel, Hillel J.; Thomas, Peter J.

    2011-12-01

    , the sun, earth and moon) proved to be far more difficult. In the late nineteenth century, Poincaré made significant progress on this problem, introducing a geometric method of reasoning about solutions to differential equations (Diacu and Holmes 1996). This work had a powerful impact on mathematicians and physicists, and also began to influence biology. In his 1925 book, based on his work starting in 1907, and that of others, Lotka used nonlinear differential equations and concepts from dynamical systems theory to analyze a wide variety of biological problems, including oscillations in the numbers of predators and prey (Lotka 1925). Although little was known in detail about the function of the nervous system, Lotka concluded his book with speculations about consciousness and the implications this might have for creating a mathematical formulation of biological systems. Much experimental work in the 1930s and 1940s focused on the biophysical mechanisms of excitability in neural tissue, and Rashevsky and others continued to apply tools and concepts from nonlinear dynamical systems theory as a means of providing a more general framework for understanding these results (Rashevsky 1960, Landahl and Podolsky 1949). The publication of Hodgkin and Huxley's classic quantitative model of the action potential in 1952 created a new impetus for these studies (Hodgkin and Huxley 1952). In 1955, FitzHugh published an important paper that summarized much of the earlier literature, and used concepts from phase plane analysis such as asymptotic stability, saddle points, separatrices and the role of noise to provide a deeper theoretical and conceptual understanding of threshold phenomena (Fitzhugh 1955, Izhikevich and FitzHugh 2006). The Fitzhugh-Nagumo equations constituted an important two-dimensional simplification of the four-dimensional Hodgkin and Huxley equations, and gave rise to an extensive literature of analysis. Many of the papers in this special issue build on tools

  4. Cognitive and emotional control of pain and its disruption in chronic pain

    OpenAIRE

    Bushnell, M. Catherine; Čeko, Marta; Low, Lucie A.

    2013-01-01

    Chronic pain is one of the most prevalent health problems in our modern world, with millions of people debilitated by conditions such as back pain, headache and arthritis. To address this growing problem, many people are turning to mind–body therapies, including meditation, yoga and cognitive behavioural therapy. This article will review the neural mechanisms underlying the modulation of pain by cognitive and emotional states — important components of mind–body therapies. It will also examine...

  5. Chronic Clomipramine Treatment Reverses Core Symptom of Depression in Subordinate Tree Shrews

    OpenAIRE

    Jing Wang; Anping Chai; Qixin Zhou; Longbao Lv; Liping Wang; Yuexiong Yang; Lin Xu

    2013-01-01

    Chronic stress is the major cause of clinical depression. The behavioral signs of depression, including anhedonia, learning and memory deficits, and sleep disruption, result from the damaging effects of stress hormones on specific neural pathways. The Chinese tree shrew (Tupaia belangeri chinensis) is an aggressive non-human primate with a hierarchical social structure that has become a well-established model of the behavioral, endocrine, and neurobiological changes associated with stress-ind...

  6. Enhanced biocompatibility of neural probes by integrating microstructures and delivering anti-inflammatory agents via microfluidic channels

    Science.gov (United States)

    Liu, Bin; Kim, Eric; Meggo, Anika; Gandhi, Sachin; Luo, Hao; Kallakuri, Srinivas; Xu, Yong; Zhang, Jinsheng

    2017-04-01

    Objective. Biocompatibility is a major issue for chronic neural implants, involving inflammatory and wound healing responses of neurons and glial cells. To enhance biocompatibility, we developed silicon-parylene hybrid neural probes with open architecture electrodes, microfluidic channels and a reservoir for drug delivery to suppress tissue responses. Approach. We chronically implanted our neural probes in the rat auditory cortex and investigated (1) whether open architecture electrode reduces inflammatory reaction by measuring glial responses; and (2) whether delivery of antibiotic minocycline reduces inflammatory and tissue reaction. Four weeks after implantation, immunostaining for glial fibrillary acid protein (astrocyte marker) and ionizing calcium-binding adaptor molecule 1 (macrophages/microglia cell marker) were conducted to identify immunoreactive astrocyte and microglial cells, and to determine the extent of astrocytes and microglial cell reaction/activation. A comparison was made between using traditional solid-surface electrodes and newly-designed electrodes with open architecture, as well as between deliveries of minocycline and artificial cerebral-spinal fluid diffused through microfluidic channels. Main results. The new probes with integrated micro-structures induced minimal tissue reaction compared to traditional electrodes at 4 weeks after implantation. Microcycline delivered through integrated microfluidic channels reduced tissue response as indicated by decreased microglial reaction around the neural probes implanted. Significance. The new design will help enhance the long-term stability of the implantable devices.

  7. Biodegradable Cell-Seeded Nanofiber Scaffolds for Neural Repair

    Directory of Open Access Journals (Sweden)

    Karen C. Cheung

    2011-10-01

    Full Text Available Central and peripheral neural injuries are traumatic and can lead to loss of motor and sensory function, chronic pain, and permanent disability. Strategies that bridge the site of injury and allow axonal regeneration promise to have a large impact on restoring quality of life for these patients. Engineered materials can be used to guide axonal growth. Specifically, nanofiber structures can mimic the natural extracellular matrix, and aligned nanofibers have been shown to direct neurite outgrowth and support axon regeneration. In addition, cell-seeded scaffolds can assist in the remyelination of the regenerating axons. The electrospinning process allows control over fiber diameter, alignment, porosity, and morphology. Biodegradable polymers have been electrospun and their use in tissue engineering has been demonstrated. This paper discusses aspects of electrospun biodegradable nanofibers for neural regeneration, how fiber alignment affects cell alignment, and how cell-seeded scaffolds can increase the effectiveness of such implants.

  8. Neural Network Controlled Visual Saccades

    Science.gov (United States)

    Johnson, Jeffrey D.; Grogan, Timothy A.

    1989-03-01

    The paper to be presented will discuss research on a computer vision system controlled by a neural network capable of learning through classical (Pavlovian) conditioning. Through the use of unconditional stimuli (reward and punishment) the system will develop scan patterns of eye saccades necessary to differentiate and recognize members of an input set. By foveating only those portions of the input image that the system has found to be necessary for recognition the drawback of computational explosion as the size of the input image grows is avoided. The model incorporates many features found in animal vision systems, and is governed by understandable and modifiable behavior patterns similar to those reported by Pavlov in his classic study. These behavioral patterns are a result of a neuronal model, used in the network, explicitly designed to reproduce this behavior.

  9. Primary neural leprosy: systematic review

    Directory of Open Access Journals (Sweden)

    Jose Antonio Garbino

    2013-06-01

    Full Text Available The authors proposed a systematic review on the current concepts of primary neural leprosy by consulting the following online databases: MEDLINE, Lilacs/SciELO, and Embase. Selected studies were classified based on the degree of recommendation and levels of scientific evidence according to the “Oxford Centre for Evidence-based Medicine”. The following aspects were reviewed: cutaneous clinical and laboratorial investigations, i.e. skin clinical exam, smears, and biopsy, and Mitsuda's reaction; neurological investigation (anamnesis, electromyography and nerve biopsy; serological investigation and molecular testing, i.e. serological testing for the detection of the phenolic glycolipid 1 (PGL-I and the polymerase chain reaction (PCR; and treatment (classification criteria for the definition of specific treatment, steroid treatment, and cure criteria.

  10. Subspace learning of neural networks

    CERN Document Server

    Cheng Lv, Jian; Zhou, Jiliu

    2010-01-01

    PrefaceChapter 1. Introduction1.1 Introduction1.1.1 Linear Neural Networks1.1.2 Subspace Learning1.2 Subspace Learning Algorithms1.2.1 PCA Learning Algorithms1.2.2 MCA Learning Algorithms1.2.3 ICA Learning Algorithms1.3 Methods for Convergence Analysis1.3.1 SDT Method1.3.2 DCT Method1.3.3 DDT Method1.4 Block Algorithms1.5 Simulation Data Set and Notation1.6 ConclusionsChapter 2. PCA Learning Algorithms with Constants Learning Rates2.1 Oja's PCA Learning Algorithms2.1.1 The Algorithms2.1.2 Convergence Issue2.2 Invariant Sets2.2.1 Properties of Invariant Sets2.2.2 Conditions for Invariant Sets2.

  11. Neural substrates of language acquisition.

    Science.gov (United States)

    Kuhl, Patricia; Rivera-Gaxiola, Maritza

    2008-01-01

    Infants learn language(s) with apparent ease, and the tools of modern neuroscience are providing valuable information about the mechanisms that underlie this capacity. Noninvasive, safe brain technologies have now been proven feasible for use with children starting at birth. The past decade has produced an explosion in neuroscience research examining young children's processing of language at the phonetic, word, and sentence levels. At all levels of language, the neural signatures of learning can be documented at remarkably early points in development. Individual continuity in linguistic development from infants' earliest responses to phonemes is reflected in infants' language abilities in the second and third year of life, a finding with theoretical and clinical implications. Developmental neuroscience studies using language are beginning to answer questions about the origins of humans' language faculty.

  12. Some neural effects of adenosin.

    Science.gov (United States)

    Haulică, I; Brănişteanu, D D; Petrescu, G H

    1978-01-01

    The possible neural effects of adenosine were investigated by using electrophysiological techniques at the level of some central and peripheral synapses. The evoked potentials in the somatosensorial cerebral cortex are influenced according to both the type of administration and the level of the electrical stimulation. While the local application does not induce significant alterations, the intrathalamic injections and the perfusion of the IIIrd cerebral ventricle do change the distribution of activated units at the level of different cortical layers especially during the peripheral stimulation. The frequency of spontaneous miniature discharges intracellularly recorded in the neuromuscular junction (mepp) is significantly depressed by adenosine. This effect is calcium- and dose-dependent. The end plate potentials (EPP) were also depressed. The statistical binomial analysis of the phenomenon indicated that adenosine induces a decrease if the presynaptic pool of the available transmitter. The data obtained demonstrate a presynaptic inhibitory action of adenosine beside its known vascular and metaholic effects.

  13. Salience-Affected Neural Networks

    CERN Document Server

    Remmelzwaal, Leendert A; Ellis, George F R

    2010-01-01

    We present a simple neural network model which combines a locally-connected feedforward structure, as is traditionally used to model inter-neuron connectivity, with a layer of undifferentiated connections which model the diffuse projections from the human limbic system to the cortex. This new layer makes it possible to model global effects such as salience, at the same time as the local network processes task-specific or local information. This simple combination network displays interactions between salience and regular processing which correspond to known effects in the developing brain, such as enhanced learning as a result of heightened affect. The cortex biases neuronal responses to affect both learning and memory, through the use of diffuse projections from the limbic system to the cortex. Standard ANNs do not model this non-local flow of information represented by the ascending systems, which are a significant feature of the structure of the brain, and although they do allow associational learning with...

  14. A chronic generalized bi-directional brain-machine interface

    Science.gov (United States)

    Rouse, A. G.; Stanslaski, S. R.; Cong, P.; Jensen, R. M.; Afshar, P.; Ullestad, D.; Gupta, R.; Molnar, G. F.; Moran, D. W.; Denison, T. J.

    2011-06-01

    A bi-directional neural interface (NI) system was designed and prototyped by incorporating a novel neural recording and processing subsystem into a commercial neural stimulator architecture. The NI system prototype leverages the system infrastructure from an existing neurostimulator to ensure reliable operation in a chronic implantation environment. In addition to providing predicate therapy capabilities, the device adds key elements to facilitate chronic research, such as four channels of electrocortigram/local field potential amplification and spectral analysis, a three-axis accelerometer, algorithm processing, event-based data logging, and wireless telemetry for data uploads and algorithm/configuration updates. The custom-integrated micropower sensor and interface circuits facilitate extended operation in a power-limited device. The prototype underwent significant verification testing to ensure reliability, and meets the requirements for a class CF instrument per IEC-60601 protocols. The ability of the device system to process and aid in classifying brain states was preclinically validated using an in vivo non-human primate model for brain control of a computer cursor (i.e. brain-machine interface or BMI). The primate BMI model was chosen for its ability to quantitatively measure signal decoding performance from brain activity that is similar in both amplitude and spectral content to other biomarkers used to detect disease states (e.g. Parkinson's disease). A key goal of this research prototype is to help broaden the clinical scope and acceptance of NI techniques, particularly real-time brain state detection. These techniques have the potential to be generalized beyond motor prosthesis, and are being explored for unmet needs in other neurological conditions such as movement disorders, stroke and epilepsy.

  15. Neural networks for damage identification

    Energy Technology Data Exchange (ETDEWEB)

    Paez, T.L.; Klenke, S.E.

    1997-11-01

    Efforts to optimize the design of mechanical systems for preestablished use environments and to extend the durations of use cycles establish a need for in-service health monitoring. Numerous studies have proposed measures of structural response for the identification of structural damage, but few have suggested systematic techniques to guide the decision as to whether or not damage has occurred based on real data. Such techniques are necessary because in field applications the environments in which systems operate and the measurements that characterize system behavior are random. This paper investigates the use of artificial neural networks (ANNs) to identify damage in mechanical systems. Two probabilistic neural networks (PNNs) are developed and used to judge whether or not damage has occurred in a specific mechanical system, based on experimental measurements. The first PNN is a classical type that casts Bayesian decision analysis into an ANN framework; it uses exemplars measured from the undamaged and damaged system to establish whether system response measurements of unknown origin come from the former class (undamaged) or the latter class (damaged). The second PNN establishes the character of the undamaged system in terms of a kernel density estimator of measures of system response; when presented with system response measures of unknown origin, it makes a probabilistic judgment whether or not the data come from the undamaged population. The physical system used to carry out the experiments is an aerospace system component, and the environment used to excite the system is a stationary random vibration. The results of damage identification experiments are presented along with conclusions rating the effectiveness of the approaches.

  16. Discontinuities in recurrent neural networks.

    Science.gov (United States)

    Gavaldá, R; Siegelmann, H T

    1999-04-01

    This article studies the computational power of various discontinuous real computational models that are based on the classical analog recurrent neural network (ARNN). This ARNN consists of finite number of neurons; each neuron computes a polynomial net function and a sigmoid-like continuous activation function. We introduce arithmetic networks as ARNN augmented with a few simple discontinuous (e.g., threshold or zero test) neurons. We argue that even with weights restricted to polynomial time computable reals, arithmetic networks are able to compute arbitrarily complex recursive functions. We identify many types of neural networks that are at least as powerful as arithmetic nets, some of which are not in fact discontinuous, but they boost other arithmetic operations in the net function (e.g., neurons that can use divisions and polynomial net functions inside sigmoid-like continuous activation functions). These arithmetic networks are equivalent to the Blum-Shub-Smale model, when the latter is restricted to a bounded number of registers. With respect to implementation on digital computers, we show that arithmetic networks with rational weights can be simulated with exponential precision, but even with polynomial-time computable real weights, arithmetic networks are not subject to any fixed precision bounds. This is in contrast with the ARNN that are known to demand precision that is linear in the computation time. When nontrivial periodic functions (e.g., fractional part, sine, tangent) are added to arithmetic networks, the resulting networks are computationally equivalent to a massively parallel machine. Thus, these highly discontinuous networks can solve the presumably intractable class of PSPACE-complete problems in polynomial time.

  17. Contextual behavior and neural circuits

    Directory of Open Access Journals (Sweden)

    Inah eLee

    2013-05-01

    Full Text Available Animals including humans engage in goal-directed behavior flexibly in response to items and their background, which is called contextual behavior in this review. Although the concept of context has long been studied, there are differences among researchers in defining and experimenting with the concept. The current review aims to provide a categorical framework within which not only the neural mechanisms of contextual information processing but also the contextual behavior can be studied in more concrete ways. For this purpose, we categorize contextual behavior into three subcategories as follows by considering the types of interactions among context, item, and response: contextual response selection, contextual item selection, and contextual item-response selection. Contextual response selection refers to the animal emitting different types of responses to the same item depending on the context in the background. Contextual item selection occurs when there are multiple items that need to be chosen in a contextual manner. Finally, when multiple items and multiple contexts are involved, contextual item-response selection takes place whereby the animal either choose an item or inhibit such a response depending on item-context paired association. The literature suggests that the rhinal cortical regions and the hippocampal formation play key roles in mnemonically categorizing and recognizing contextual representations and the associated items. In addition, it appears that the fronto-striatal cortical loops in connection with the contextual information-processing areas critically control the flexible deployment of adaptive action sets and motor responses for maximizing goals. We suggest that contextual information processing should be investigated in experimental settings where contextual stimuli and resulting behaviors are clearly defined and measurable, considering the dynamic top-down and bottom-up interactions among the neural systems for

  18. Contextual behavior and neural circuits

    Science.gov (United States)

    Lee, Inah; Lee, Choong-Hee

    2013-01-01

    Animals including humans engage in goal-directed behavior flexibly in response to items and their background, which is called contextual behavior in this review. Although the concept of context has long been studied, there are differences among researchers in defining and experimenting with the concept. The current review aims to provide a categorical framework within which not only the neural mechanisms of contextual information processing but also the contextual behavior can be studied in more concrete ways. For this purpose, we categorize contextual behavior into three subcategories as follows by considering the types of interactions among context, item, and response: contextual response selection, contextual item selection, and contextual item–response selection. Contextual response selection refers to the animal emitting different types of responses to the same item depending on the context in the background. Contextual item selection occurs when there are multiple items that need to be chosen in a contextual manner. Finally, when multiple items and multiple contexts are involved, contextual item–response selection takes place whereby the animal either chooses an item or inhibits such a response depending on item–context paired association. The literature suggests that the rhinal cortical regions and the hippocampal formation play key roles in mnemonically categorizing and recognizing contextual representations and the associated items. In addition, it appears that the fronto-striatal cortical loops in connection with the contextual information-processing areas critically control the flexible deployment of adaptive action sets and motor responses for maximizing goals. We suggest that contextual information processing should be investigated in experimental settings where contextual stimuli and resulting behaviors are clearly defined and measurable, considering the dynamic top-down and bottom-up interactions among the neural systems for contextual behavior

  19. Neural networks for nuclear spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.; Kangas, L.J.; Hashem, S.; Kouzes, R.T. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1995-12-31

    In this paper two applications of artificial neural networks (ANNs) in nuclear spectroscopy analysis are discussed. In the first application, an ANN assigns quality coefficients to alpha particle energy spectra. These spectra are used to detect plutonium contamination in the work environment. The quality coefficients represent the levels of spectral degradation caused by miscalibration and foreign matter affecting the instruments. A set of spectra was labeled with quality coefficients by an expert and used to train the ANN expert system. Our investigation shows that the expert knowledge of spectral quality can be transferred to an ANN system. The second application combines a portable gamma-ray spectrometer with an ANN. In this system the ANN is used to automatically identify, radioactive isotopes in real-time from their gamma-ray spectra. Two neural network paradigms are examined: the linear perception and the optimal linear associative memory (OLAM). A comparison of the two paradigms shows that OLAM is superior to linear perception for this application. Both networks have a linear response and are useful in determining the composition of an unknown sample when the spectrum of the unknown is a linear superposition of known spectra. One feature of this technique is that it uses the whole spectrum in the identification process instead of only the individual photo-peaks. For this reason, it is potentially more useful for processing data from lower resolution gamma-ray spectrometers. This approach has been tested with data generated by Monte Carlo simulations and with field data from sodium iodide and Germanium detectors. With the ANN approach, the intense computation takes place during the training process. Once the network is trained, normal operation consists of propagating the data through the network, which results in rapid identification of samples. This approach is useful in situations that require fast response where precise quantification is less important.

  20. Nonequilibrium landscape theory of neural networks.

    Science.gov (United States)

    Yan, Han; Zhao, Lei; Hu, Liang; Wang, Xidi; Wang, Erkang; Wang, Jin

    2013-11-05

    The brain map project aims to map out the neuron connections of the human brain. Even with all of the wirings mapped out, the global and physical understandings of the function and behavior are still challenging. Hopfield quantified the learning and memory process of symmetrically connected neural networks globally through equilibrium energy. The energy basins of attractions represent memories, and the memory retrieval dynamics is determined by the energy gradient. However, the realistic neural networks are asymmetrically connected, and oscillations cannot emerge from symmetric neural networks. Here, we developed a nonequilibrium landscape-flux theory for realistic asymmetrically connected neural networks. We uncovered the underlying potential landscape and the associated Lyapunov function for quantifying the global stability and function. We found the dynamics and oscillations in human brains responsible for cognitive processes and physiological rhythm regulations are determined not only by the landscape gradient but also by the flux. We found that the flux is closely related to the degrees of the asymmetric connections in neural networks and is the origin of the neural oscillations. The neural oscillation landscape shows a closed-ring attractor topology. The landscape gradient attracts the network down to the ring. The flux is responsible for coherent oscillations on the ring. We suggest the flux may provide the driving force for associations among memories. We applied our theory to rapid-eye movement sleep cycle. We identified the key regulation factors for function through global sensitivity analysis of landscape topography against wirings, which are in good agreements with experiments.