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Sample records for brain slice recordings

  1. Whole-cell Patch-clamp Recordings in Brain Slices.

    Science.gov (United States)

    Segev, Amir; Garcia-Oscos, Francisco; Kourrich, Saïd

    2016-01-01

    Whole-cell patch-clamp recording is an electrophysiological technique that allows the study of the electrical properties of a substantial part of the neuron. In this configuration, the micropipette is in tight contact with the cell membrane, which prevents current leakage and thereby provides more accurate ionic current measurements than the previously used intracellular sharp electrode recording method. Classically, whole-cell recording can be performed on neurons in various types of preparations, including cell culture models, dissociated neurons, neurons in brain slices, and in intact anesthetized or awake animals. In summary, this technique has immensely contributed to the understanding of passive and active biophysical properties of excitable cells. A major advantage of this technique is that it provides information on how specific manipulations (e.g., pharmacological, experimenter-induced plasticity) may alter specific neuronal functions or channels in real-time. Additionally, significant opening of the plasma membrane allows the internal pipette solution to freely diffuse into the cytoplasm, providing means for introducing drugs, e.g., agonists or antagonists of specific intracellular proteins, and manipulating these targets without altering their functions in neighboring cells. This article will focus on whole-cell recording performed on neurons in brain slices, a preparation that has the advantage of recording neurons in relatively well preserved brain circuits, i.e., in a physiologically relevant context. In particular, when combined with appropriate pharmacology, this technique is a powerful tool allowing identification of specific neuroadaptations that occurred following any type of experiences, such as learning, exposure to drugs of abuse, and stress. In summary, whole-cell patch-clamp recordings in brain slices provide means to measure in ex vivo preparation long-lasting changes in neuronal functions that have developed in intact awake animals

  2. Dose-response testing of peptides by hippocampal brain slice recording.

    Science.gov (United States)

    Phillips, M I; Palovcik, R A

    1989-01-01

    The brain slice chamber described offers a method of studying, with intracellular electrodes, the relationship of response to dose of peptides. By raising the level of the slices 1 mm above the level of flowing perfusion medium, we can test substances in known concentrations, free from artifacts, during long duration, stable intracellular recordings. Manipulation of Ca2+/Mg2+ ratios in the medium can help to define synaptic and second messenger mediation of the responses. The addition of substances to the perfusion medium in this system could be combined with iontophoresis and/or micropressure techniques. Pathways in the slices may also be stimulated electrically and analyzed for the involvement of various synaptic transmitters. The results with the method so far show distinct differences among the peptides studied. Thus, there are several advantages to this method in establishing the physiological role of peptides in the brain.

  3. Extending the viability of acute brain slices.

    Science.gov (United States)

    Buskila, Yossi; Breen, Paul P; Tapson, Jonathan; van Schaik, André; Barton, Matthew; Morley, John W

    2014-01-01

    The lifespan of an acute brain slice is approximately 6-12 hours, limiting potential experimentation time. We have designed a new recovery incubation system capable of extending their lifespan to more than 36 hours. This system controls the temperature of the incubated artificial cerebral spinal fluid (aCSF) while continuously passing the fluid through a UVC filtration system and simultaneously monitoring temperature and pH. The combination of controlled temperature and UVC filtering maintains bacteria levels in the lag phase and leads to the dramatic extension of the brain slice lifespan. Brain slice viability was validated through electrophysiological recordings as well as live/dead cell assays. This system benefits researchers by monitoring incubation conditions and standardizing this artificial environment. It further provides viable tissue for two experimental days, reducing the time spent preparing brain slices and the number of animals required for research. PMID:24930889

  4. Direct-current Stimulation and Multi-electrode Array Recording of Seizure-like Activity in Mice Brain Slice Preparation.

    Science.gov (United States)

    Lu, Hsiang-Chin; Chang, Wei-Jen; Chang, Wei-Pang; Shyu, Bai-Chuang

    2016-01-01

    Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the stimulation parameters (e.g., orientation, field strength, and stimulation duration) need to be examined in mice brain slice preparations. Testing and arranging the orientation of the electrode relative to the position of the mice brain slice are feasible. The present method preserves the thalamocingulate pathway to evaluate the effect of DCS on anterior cingulate cortex seizure-like activities. The results of the multichannel array recordings indicated that cathodal DCS significantly decreased the amplitude of the stimulation-evoked responses and duration of 4-aminopyridine and bicuculline-induced seizure-like activity. This study also found that cathodal DCS applications at 15 min caused long-term depression in the thalamocingulate pathway. The present study investigates the effects of DCS on thalamocingulate synaptic plasticity and acute seizure-like activities. The current procedure can test the optimal stimulation parameters including orientation, field strength, and stimulation duration in an in vitro mouse model. Also, the method can evaluate the effects of DCS on cortical seizure-like activities at both the cellular and network levels. PMID:27341682

  5. Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation

    Directory of Open Access Journals (Sweden)

    Tamar ePashut

    2014-06-01

    Full Text Available Although transcranial magnetic stimulation (TMS is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

  6. Image reconstruction for brain CT slices

    Institute of Scientific and Technical Information of China (English)

    吴建明; 施鹏飞

    2004-01-01

    Different modalities in biomedical images, like CT, MRI and PET scanners, provide detailed cross-sectional views of human anatomy. This paper introduces three-dimensional brain reconstruction based on CT slices. It contains filtering, fuzzy segmentation, matching method of contours, cell array structure and image animation. Experimental results have shown its validity. The innovation is matching method of contours and fuzzy segmentation algorithm of CT slices.

  7. Long-term brain slice culturing in a microfluidic platform

    DEFF Research Database (Denmark)

    Vedarethinam, Indumathi; Avaliani, N.; Tønnesen, J.;

    2011-01-01

    In this work, we present the development of a transparent poly(methyl methacrylate) (PMMA) based microfluidic culture system for handling long-term brain slice cultures independent of an incubator. The different stages of system development have been validated by culturing GFP producing brain...... brain slice culturing for 16 days....

  8. Classification of CT-brain slices based on local histograms

    Science.gov (United States)

    Avrunin, Oleg G.; Tymkovych, Maksym Y.; Pavlov, Sergii V.; Timchik, Sergii V.; Kisała, Piotr; Orakbaev, Yerbol

    2015-12-01

    Neurosurgical intervention is a very complicated process. Modern operating procedures based on data such as CT, MRI, etc. Automated analysis of these data is an important task for researchers. Some modern methods of brain-slice segmentation use additional data to process these images. Classification can be used to obtain this information. To classify the CT images of the brain, we suggest using local histogram and features extracted from them. The paper shows the process of feature extraction and classification CT-slices of the brain. The process of feature extraction is specialized for axial cross-section of the brain. The work can be applied to medical neurosurgical systems.

  9. Perfused drop microfluidic device for brain slice culture-based drug discovery.

    Science.gov (United States)

    Liu, Jing; Pan, Liping; Cheng, Xuanhong; Berdichevsky, Yevgeny

    2016-06-01

    Living slices of brain tissue are widely used to model brain processes in vitro. In addition to basic neurophysiology studies, brain slices are also extensively used for pharmacology, toxicology, and drug discovery research. In these experiments, high parallelism and throughput are critical. Capability to conduct long-term electrical recording experiments may also be necessary to address disease processes that require protein synthesis and neural circuit rewiring. We developed a novel perfused drop microfluidic device for use with long term cultures of brain slices (organotypic cultures). Slices of hippocampus were placed into wells cut in polydimethylsiloxane (PDMS) film. Fluid level in the wells was hydrostatically controlled such that a drop was formed around each slice. The drops were continuously perfused with culture medium through microchannels. We found that viable organotypic hippocampal slice cultures could be maintained for at least 9 days in vitro. PDMS microfluidic network could be readily integrated with substrate-printed microelectrodes for parallel electrical recordings of multiple perfused organotypic cultures on a single MEA chip. We expect that this highly scalable perfused drop microfluidic device will facilitate high-throughput drug discovery and toxicology. PMID:27194028

  10. Whole brain CT perfusion on a 320-slice CT scanner

    Directory of Open Access Journals (Sweden)

    Jai Jai Shiva Shankar

    2011-01-01

    Full Text Available Computed tomography perfusion (CTP has been criticized for limited brain coverage. This may result in inadequate coverage of the lesion, inadequate arterial input function, or omission of the lesion within the target perfusion volume. The availability of 320-slice CT scanners offers whole brain coverage. This minimizes the chances of misregistration of lesions regardless of location, and makes the selection of the arterial input function easy. We present different clinical scenarios in which whole brain CTP is especially useful.

  11. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    Science.gov (United States)

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates. PMID:26488641

  12. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    Science.gov (United States)

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates.

  13. Novel culturing platform for brain slices and neuronal cells

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya;

    2015-01-01

    In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been te...

  14. A brain slice bath for physiology and compound microscopy, with dual-sided perifusion.

    Science.gov (United States)

    Heyward, P M

    2010-12-01

    Contemporary in vitro brain slice studies can employ compound microscopes to identify individual neurons or their processes for physiological recording or imaging. This requires that the bath used to maintain the tissue fits within the working distances of a water-dipping objective and microscope condenser. A common means of achieving this is to maintain thin tissue slices on the glass floor of a recording bath, exposing only one surface of the tissue to oxygenated bathing medium. Emerging evidence suggests that physiology can be compromised by this approach. Flowing medium past both sides of submerged brain slices is optimal, but recording baths utilizing this principle are not readily available for use on compound microscopes. This paper describes a tissue bath designed specifically for microscopy and physiological recording, in which temperature-controlled medium flows past both sides of the slices. A particular feature of this design is the use of concentric mesh rings to support and transport the live tissue without mechanical disturbance. The design is also easily adapted for use with thin acute slices, cultured slices, and acutely dispersed or cultured cells maintained either on cover slips or placed directly on the floor of the bath. The low profile of the bath provides a low angle of approach for electrodes, and allows use of standard condensers, nosepieces and water-dipping objective lenses. If visualization of individual neurons is not required, the bath can be mounted on a simple stand and used with a dissecting microscope. Heating is integral to the bath, and any temperature controller capable of driving a resistive load can be used. The bath is robust, readily constructed and requires minimal maintenance. Full construction and operation details are given. PMID:21077881

  15. The energy demand of fast neuronal network oscillations: insights from brain slice preparations

    Directory of Open Access Journals (Sweden)

    Oliver eKann

    2012-01-01

    Full Text Available Fast neuronal network oscillations in the gamma range (30-100 Hz in the cerebral cortex have been implicated in higher cognitive functions such as sensual perception, working memory, and, perhaps, consciousness. However, little is known about the energy demand of gamma oscillations. This is mainly caused by technical limitations that are associated with simultaneous recordings of neuronal activity and energy metabolism in small neuronal networks and at the level of mitochondria in vivo. Thus recent studies have focused on brain slice preparations to address the energy demand of gamma oscillations in vitro. Here, reports will be summarized and discussed that combined electrophysiological recordings, oxygen sensor microelectrodes and live-cell fluorescence imaging in acutely prepared slices and organotypic slice cultures of the hippocampus from both, mouse and rat. These reports consistently show that gamma oscillations can be reliably induced in hippocampal slice preparations by different pharmacological tools. They suggest that gamma oscillations are associated with high energy demand, requiring both rapid adaptation of oxidative energy metabolism and sufficient supply with oxygen and nutrients. These findings might help to explain the exceptional vulnerability of higher cognitive functions during pathological processes of the brain, such as circulatory disturbances, genetic mitochondrial diseases, and neurodegeneration.

  16. Differential Conditioning of Associative Synaptic Enhancement in Hippocampal Brain Slices

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    Kelso, Stephen R.; Brown, Thomas H.

    1986-04-01

    An electrophysiological stimulation paradigm similar to one that produces Pavlovian conditioning was applied to synaptic inputs to pyramidal neurons of hippocampal brain slices. Persistent synaptic enhancement was induced in one of two weak synaptic inputs by pairing high-frequency electrical stimulation of the weak input with stimulation of a third, stronger input to the same region. Forward (temporally overlapping) but not backward (temporally separate) pairings caused this enhancement. Thus hippocampal synapses in vitro can undergo the conditional and selective type of associative modification that could provide the substrate for some of the mnemonic functions in which the hippocampus is thought to participate.

  17. Fluidic system for long-term in vitro culturing and monitoring of organotypic brain slices

    DEFF Research Database (Denmark)

    Bakmand, Tanya; Troels-Smith, Ane R.; Dimaki, Maria;

    2015-01-01

    Brain slice preparations cultured in vitro have long been used as a simplified model for studying brain development, electrophysiology, neurodegeneration and neuroprotection. In this paper an open fluidic system developed for improved long term culturing of organotypic brain slices is presented. ...

  18. Fast whole-brain optical tomography capable of automated slice-collection (Conference Presentation)

    Science.gov (United States)

    Yuan, Jing; Jiang, Tao; Deng, Lei; Long, Beng; Peng, Jie; Luo, Qingming; Gong, Hui

    2016-03-01

    Acquiring brain-wide composite information of neuroanatomical and molecular phenotyping is crucial to understand brain functions. However, current whole-brain imaging methods based on mechnical sectioning haven't achieved brain-wide acquisition of both neuroanatomical and molecular phenotyping due to the lack of appropriate whole-brain immunostaining of embedded samples. Here, we present a novel strategy of acquiring brain-wide structural and molecular maps in the same brain, combining whole-brain imaging and subsequent immunostaining of automated-collected slices. We developed a whole-brain imaging system capable of automatically imaging and then collecting imaged tissue slices in order. The system contains three parts: structured illumination microscopy for high-throughput optical sectioning, vibratome for high-precision sectioning and slice-collection device for automated collecting of tissue slices. Through our system, we could acquire a whole-brain dataset of agarose-embedded mouse brain at lateral resolution of 0.33 µm with z-interval sampling of 100 µm in 9 h, and automatically collect the imaged slices in sequence. Subsequently, we performed immunohistochemistry of the collected slices in the routine way. We acquired mouse whole-brain imaging datasets of multiple specific types of neurons, proteins and gene expression profiles. We believe our method could accelerate systematic analysis of brain anatomical structure with specific proteins or genes expression information and understanding how the brain processes information and generates behavior.

  19. Label-free dopamine imaging in live rat brain slices.

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    Sarkar, Bidyut; Banerjee, Arkarup; Das, Anand Kant; Nag, Suman; Kaushalya, Sanjeev Kumar; Tripathy, Umakanta; Shameem, Mohammad; Shukla, Shubha; Maiti, Sudipta

    2014-05-21

    Dopaminergic neurotransmission has been investigated extensively, yet direct optical probing of dopamine has not been possible in live cells. Here we image intracellular dopamine with sub-micrometer three-dimensional resolution by harnessing its intrinsic mid-ultraviolet (UV) autofluorescence. Two-photon excitation with visible light (540 nm) in conjunction with a non-epifluorescent detection scheme is used to circumvent the UV toxicity and the UV transmission problems. The method is established by imaging dopamine in a dopaminergic cell line and in control cells (glia), and is validated by mass spectrometry. We further show that individual dopamine vesicles/vesicular clusters can be imaged in cultured rat brain slices, thereby providing a direct visualization of the intracellular events preceding dopamine release induced by depolarization or amphetamine exposure. Our technique opens up a previously inaccessible mid-ultraviolet spectral regime (excitation ~270 nm, emission free imaging of native molecules in live tissue.

  20. Slices

    KAUST Repository

    McCrae, James

    2011-01-01

    Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours of intersection of planes with a 3D object, for creating shape abstractions, motivated by their popularity in art and engineering. We first perform a user study to show that humans do define consistent and similar planar section proxies for common objects. Interestingly, we observe a strong correlation between user-defined planes and geometric features of objects. Further we show that the problem of finding the minimum set of planes that capture a set of 3D geometric shape features is both NP-hard and not always the proxy a user would pick. Guided by the principles inferred from our user study, we present an algorithm that progressively selects planes to maximize feature coverage, which in turn influence the selection of subsequent planes. The algorithmic framework easily incorporates various shape features, while their relative importance values are computed and validated from the user study data. We use our algorithm to compute planar slices for various objects, validate their utility towards object abstraction using a second user study, and conclude showing the potential applications of the extracted planar slice shape proxies. © 2011 ACM.

  1. Organotypic hippocampal slice cultures for studies of brain damage, neuroprotection and neurorepair

    DEFF Research Database (Denmark)

    Noraberg, Jens; Poulsen, Frantz Rom; Blaabjerg, Morten;

    2005-01-01

    Slices of developing brain tissue can be grown for several weeks as so-called organotypic slice cultures. Here we summarize and review studies using hippocampal slice cultures to investigate mechanisms and treatment strategies for the neurodegenerative disorders like stroke (cerebral ischemia......), Alzheimer's disease (AD) and epilepsia. Studies of non-excitotoxic neurotoxic compounds and the experimental use of slice cultures in studies of HIV neurotoxicity, traumatic brain injury (TBI) and neurogenesis are included. For cerebral ischemia, experimental models with oxygen-glucose deprivation (OGD...... in vitro models using dispersed cell cultures, experimental in vivo models, and in some instances, clinical trials. New techniques including slice culturing of hippocampal tissue from transgenic mice as well as more mature brain tissue, and slice cultures coupled to microelectrode arrays (MEAs), on...

  2. Influence of Thin Slice Reconstruction on CT Brain Perfusion Analysis

    NARCIS (Netherlands)

    Bennink, Edwin; Oosterbroek, Jaap; Horsch, Alexander D.; Dankbaar, Jan Willem; Velthuis, BK; Viergever, Max A.; de Jong, Hugo W. A. M.

    2015-01-01

    Objectives Although CT scanners generally allow dynamic acquisition of thin slices (1 mm), thick slice (>= 5 mm) reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP) reconstruction may suffer less from partial volume effec

  3. Influence of Thin Slice Reconstruction on CT Brain Perfusion Analysis.

    Directory of Open Access Journals (Sweden)

    Edwin Bennink

    Full Text Available Although CT scanners generally allow dynamic acquisition of thin slices (1 mm, thick slice (≥5 mm reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP reconstruction may suffer less from partial volume effects, and thus yield more accurate quantitative results with increased resolution. Before thin slice protocols are to be introduced clinically, it needs to be ensured that this does not affect overall CTP constancy. We studied the influence of thin slice reconstruction on average perfusion values by comparing it with standard thick slice reconstruction.From 50 patient studies, absolute and relative hemisphere averaged estimates of cerebral blood volume (CBV, cerebral blood flow (CBF, mean transit time (MTT, and permeability-surface area product (PS were analyzed using 0.8, 2.4, 4.8, and 9.6 mm slice reconstructions. Specifically, the influence of Gaussian and bilateral filtering, the arterial input function (AIF, and motion correction on the perfusion values was investigated.Bilateral filtering gave noise levels comparable to isotropic Gaussian filtering, with less partial volume effects. Absolute CBF, CBV and PS were 22%, 14% and 46% lower with 0.8 mm than with 4.8 mm slices. If the AIF and motion correction were based on thin slices prior to reconstruction of thicker slices, these differences reduced to 3%, 4% and 3%. The effect of slice thickness on relative values was very small.This study shows that thin slice reconstruction for CTP with unaltered acquisition protocol gives relative perfusion values without clinically relevant bias. It does however affect absolute perfusion values, of which CBF and CBV are most sensitive. Partial volume effects in large arteries and veins lead to overestimation of these values. The effects of reconstruction slice thickness should be taken into account when absolute perfusion values are used for clinical decision making.

  4. Effect of slice thickness on brain magnetic resonance image texture analysis

    OpenAIRE

    Heinonen Tomi; Luukkaala Tiina; Harrison Lara CV; Savio Sami J; Dastidar Prasun; Soimakallio Seppo; Eskola Hannu J

    2010-01-01

    Abstract Background The accuracy of texture analysis in clinical evaluation of magnetic resonance images depends considerably on imaging arrangements and various image quality parameters. In this paper, we study the effect of slice thickness on brain tissue texture analysis using a statistical approach and classification of T1-weighted images of clinically confirmed multiple sclerosis patients. Methods We averaged the intensities of three consecutive 1-mm slices to simulate 3-mm slices. Two h...

  5. Modification of hippocampal excitability in brain slices pretreated with a low nanomolar concentration of Zn2+.

    Science.gov (United States)

    Takeda, Atsushi; Shakushi, Yukina; Tamano, Haruna

    2015-11-01

    Synaptic Zn2+ homeostasis may be changed during brain slice preparation. However, much less attention has been paid to Zn2+ in artificial cerebrospinal fluid (ACSF) used for slice experiments than has been paid to Ca2+ . The present study assesses addition of Zn2+ to ACSF, focused on hippocampal excitability after acute brain slice preparation. When the static levels of intracellular Zn2+ and Ca2+ were compared between brain slices prepared with conventional ACSF without Zn2+ and those pretreated with ACSF containing 20 nM ZnCl2 for 1 hr, both levels were almost the same. On the other hand, intracellular Ca2+ levels were significantly increased in the stratum lucidum of the control brain slices after stimulation with high K+, although the increase was significantly suppressed by the pretreatment with ACSF containing Zn2+, suggesting that neuronal excitation is enhanced in brain slices prepared with ACSF without Zn2+. The increase in extracellular Zn2+ level, an index of glutamate release, after stimulation with high K+ was also significantly suppressed by pretreatment with ACSF containing Zn2+. When mossy fiber excitation was assessed in brain slices with FM4-64, an indicator of presynaptic activity, attenuation of FM 4-64 fluorescence based on presynaptic activity was suppressed in the stratum lucidum of brain slices pretreated with ACSF containing Zn2+. The present study indicates that hippocampal excitability is enhanced in brain slices prepared with ACSF without Zn2+. It is likely that a low nanomolar concentration of Zn2+ is necessary for ACSF. PMID:26268632

  6. Use of bipolar parallel electrodes for well-controlled microstimulation in a mouse hippocampal brain slice.

    Science.gov (United States)

    Neagu, Bogdan; Strominger, Norman L; Carpenter, David O

    2005-06-15

    In a hippocampal brain slice two types of stimulating electrodes [single (SE) or monopolar and parallel bipolar (PE)] were used to determine the optimal protocol for single pulse microstimulation. We show that even for a constant-current power source the amplitude of stimulating current (SC) is not constant, especially for short pulse widths (PW) (best estimate of the strength of electrical stimulation. For SE the evoked response is obstructed for a time interval larger than three times the PW. The stimulus artifact (SA) substantially decreases when a PE is used. The orientation of the stimulating current relative to the position of the targeted fibers (Schaffer collaterals) was controlled when using a PE. The use of PEs allowed the accurate recording of the physiological response that contains three clearly defined peaks. Stimulation can be elicited at PW as short as 30 micros when the main current is capacitive. The charge needed to elicit physiological responses was in the range of 1-40 nC (the lower values for the PE) suggesting that use of PEs is most advantageous for well-controlled microstimulation studies in brain slices.

  7. Using laser confocal scanning microscope to study ischemia-hypoxia injury in rat brain slice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The level of lipid peroxidation and cellular necrosis in rat living brain slices during brain ischemia-hypoxia injury have been observed using a laser confocal scanning microscope (LCSM) with double labeling of fluorescent probes D-399 (2,7-dichlorofluorescin diacetate) and propidium iodide (PI).The hypoxia and/or reoxygenation injury in rat brain slices is markedly decreased by pretreatment with L-NG-nitro-arginine (L-NNA) and N-acetylcysteine (NAC),showing that the nitric oxide (NO) and other free radicals play an important role in brain ischemia-hypoxia injury.

  8. Transistor needle chip for recording in brain tissue

    Science.gov (United States)

    Felderer, Florian; Fromherz, Peter

    2011-07-01

    We report on a proof-of-principle experiment for the direct interfacing of transistors with intact brain tissue. A transistor needle chip (TNC) with a TiO2 surface is fabricated from a silicon-on-insulator wafer and impaled into an acute brain slice cut from hippocampus of the rat. While stimulating the Schaffer collateral, a local field potential is recorded in stratum radiatum of the CA1 region with field-effect transistors in the central part of the slice where the tissue is not damaged by the cutting process. After the impalement, the signal amplitude is small. Within an hour, it increases to a stable level around -2 mV as is recorded with a conventional micropipette electrode. The recovery indicates that the tissue is able to adapt to the impaled chip. Upon repeated impalements at the same position, the large signal is observed without delay. A profile of the transistor signal across the slice is due to the boundary conditions of a brain slice with both surfaces held near ground potential. The experiments with the TNC prototype are a basis for the development of silicon needle chips with a large multi-transistor array (MTA) for applications in brain-computer interfacing.

  9. Binding of mescaline with subcellular fractions upon incubation of brain cortex slices with [14C] mescaline.

    Science.gov (United States)

    Datta, R K; Antopol, W; Ghosh, J J

    1977-01-01

    Incubation of brain cortex slices in the presence of glucose resulted in the permeation of about 65% of [14C] mescaline into slices. Of this, about one-third radioactivity was bound with nuclei, mitochondria, microsomes, and ribosomes. Dialysis of subcellular fractions did not markedly reduce the amounts of radioactivity bound to the fractions. The permeation into slices and the binding of mescaline to subcellular fractions were fairly time-dependent, but were inhibited by the presence of potassium cyanide, or by the absence of glucose and by heating to 80 degrees C for 1 min.

  10. Imaging of molecular surface dynamics in brain slices using single-particle tracking.

    Science.gov (United States)

    Biermann, B; Sokoll, S; Klueva, J; Missler, M; Wiegert, J S; Sibarita, J-B; Heine, M

    2014-01-01

    Organization of signalling molecules in biological membranes is crucial for cellular communication. Many receptors, ion channels and cell adhesion molecules are associated with proteins important for their trafficking, surface localization or function. These complexes are embedded in a lipid environment of varying composition. Binding affinities and stoichiometry of such complexes were so far experimentally accessible only in isolated systems or monolayers of cell culture. Visualization of molecular dynamics within signalling complexes and their correlation to specialized membrane compartments demand high temporal and spatial resolution and has been difficult to demonstrate in complex tissue like brain slices. Here we demonstrate the feasibility of single-particle tracking (SPT) in organotypic brain slices to measure molecular dynamics of lipids and transmembrane proteins in correlation to synaptic membrane compartments. This method will provide important information about the dynamics and organization of surface molecules in the complex environment of neuronal networks within brain slices. PMID:24429796

  11. Effect of slice thickness on brain magnetic resonance image texture analysis

    Directory of Open Access Journals (Sweden)

    Heinonen Tomi

    2010-10-01

    Full Text Available Abstract Background The accuracy of texture analysis in clinical evaluation of magnetic resonance images depends considerably on imaging arrangements and various image quality parameters. In this paper, we study the effect of slice thickness on brain tissue texture analysis using a statistical approach and classification of T1-weighted images of clinically confirmed multiple sclerosis patients. Methods We averaged the intensities of three consecutive 1-mm slices to simulate 3-mm slices. Two hundred sixty-four texture parameters were calculated for both the original and the averaged slices. Wilcoxon's signed ranks test was used to find differences between the regions of interest representing white matter and multiple sclerosis plaques. Linear and nonlinear discriminant analyses were applied with several separate training and test sets to determine the actual classification accuracy. Results Only moderate differences in distributions of the texture parameter value for 1-mm and simulated 3-mm-thick slices were found. Our study also showed that white matter areas are well separable from multiple sclerosis plaques even if the slice thickness differs between training and test sets. Conclusions Three-millimeter-thick magnetic resonance image slices acquired with a 1.5 T clinical magnetic resonance scanner seem to be sufficient for texture analysis of multiple sclerosis plaques and white matter tissue.

  12. Effects of ketamine, midazolam, thiopental, and propofol on brain ischemia injury in rat cerebral cortical slices

    Institute of Scientific and Technical Information of China (English)

    Qing-shengXUE; Bu-weiYU; Ze-jianWANG; Hong-zhuanCHEN

    2004-01-01

    AIM: To compare the effects of ketamine, midazolam, thiopental, and propofol on brain ischemia by the model of oxygen-glucose deprivation (OGD) in rat cerebral cortical slices. METHODS: Cerebral cortical slices were incu-bated in 2 % 2,3,5-triphenyltetrazolium chloride (TTC) solution after OGD, the damages and effects of ketamine,midazolam, thiopental, and propofol were quantitativlye evaluated by ELISA reader of absorbance (A) at 490 nm,which indicated the red formazan extracted from slices, lactic dehydrogenase (LDH) releases in the incubated supernate were also measured. RESULTS: Progressive prolongation of OGD resulted in decreases of TTC staining.The percentage of tissue injury had a positive correlation with LDH releases, r=0.9609, P<0.01. Two hours of reincubation aggravated the decrease of TTC staining compared with those slices stained immediately after OGD(P<0.01). These four anesthetics had no effects on the TTC staining of slices. Ketamine completely inhibited thedecrease of A value induced by 10 min of OGD injury. High concentrations of midazolam (10 μmol/L) and thiopental (400μmol/L) partly attenuated this decrease. Propofol at high concentration (100 μmol/L) enhanced the decrease of A value induced by 10 min of OGD injury (P<0.01). CONCLUSION; Ketamine, high concentration of midazolam and thiopental have neuroprotective effects against OGD injury in rat cerebral cortical slices, while high concentration of propofol augments OGD injury in rat cerebral cortical slices.

  13. Excitatory amino acid neurotoxicity and modulation of glutamate receptor expression in organotypic brain slice cultures

    DEFF Research Database (Denmark)

    Zimmer, J; Kristensen, Bjarne Winther; Jakobsen, B;

    2000-01-01

    Using organotypic slice cultures of hippocampus and cortex-striatum from newborn to 7 day old rats, we are currently studying the excitotoxic effects of kainic acid (KA), AMPA and NMDA and the neuroprotective effects of glutamate receptor blockers, like NBQX. For detection and quantitation...... and AMPA (and NMDA) in hippocampal slice cultures, and --b) KA and AMPA in corticostriatal slice cocultures, with demonstration of differentiated neuroprotective effects of NBQX in relation to cortex and striatum and KA and AMPA. A second set of studies include modulation of hippocampal KA......-induced excitotoxicity and KA-glutamate receptor subunit mRNA expression after long-term exposure to low, non-toxic doses of KA and NBQX. We conclude that organotypic brain slice cultures, combined with standardized procedures for quantitation of cell damage and receptor subunit changes is of great potential use...

  14. A visual thalamocortical slice.

    Science.gov (United States)

    MacLean, Jason N; Fenstermaker, Vivian; Watson, Brendon O; Yuste, Rafael

    2006-02-01

    We describe a thalamocortical slice preparation in which connectivity between the mouse lateral geniculate nucleus (LGN) and primary visual cortex (V1) is preserved. Through DiI injections in fixed brains we traced and created a three-dimensional model of the mouse visual pathways. From this computer model we designed a slice preparation that contains a projection from LGN to V1. We prepared brain slices with these predicted coordinates and demonstrated anatomical LGN-V1 connectivity in these slices after LGN tracer injections. We also revealed functional LGN-V1 connectivity by stimulating LGN electrically and detecting responses in layer 4 of V1 using calcium imaging, field potential recordings and whole-cell recordings. We also identified layer-4 neurons that receive direct thalamocortical input. Finally, we compared cortical activity after LGN stimulation with spontaneous cortical activity and found significant overlap of the spatiotemporal dynamics generated by both types of events.

  15. Targeting neurotransmitter receptors with nanoparticles in vivo allows single-molecule tracking in acute brain slices

    Science.gov (United States)

    Varela, Juan A.; Dupuis, Julien P.; Etchepare, Laetitia; Espana, Agnès; Cognet, Laurent; Groc, Laurent

    2016-03-01

    Single-molecule imaging has changed the way we understand many biological mechanisms, particularly in neurobiology, by shedding light on intricate molecular events down to the nanoscale. However, current single-molecule studies in neuroscience have been limited to cultured neurons or organotypic slices, leaving as an open question the existence of fast receptor diffusion in intact brain tissue. Here, for the first time, we targeted dopamine receptors in vivo with functionalized quantum dots and were able to perform single-molecule tracking in acute rat brain slices. We propose a novel delocalized and non-inflammatory way of delivering nanoparticles (NPs) in vivo to the brain, which allowed us to label and track genetically engineered surface dopamine receptors in neocortical neurons, revealing inherent behaviour and receptor activity regulations. We thus propose a NP-based platform for single-molecule studies in the living brain, opening new avenues of research in physiological and pathological animal models.

  16. Coupling of organotypic brain slice cultures to silicon-based arrays of electrodes

    DEFF Research Database (Denmark)

    Jahnsen, Henrik; Kristensen, Bjarne Winther; Thiébaud, P;

    1999-01-01

    Fetal or early postnatal brain tissue can be cultured in viable and healthy condition for several weeks with development and preservation of the basic cellular and connective organization as so-called organotypic brain slice cultures. Here we demonstrate and describe how it is possible to establi...... arrays it is anticipated that the setup eventually will allow long-term studies of defined neuronal networks and provide valuable information on both normal and neurotoxicological and neuropathological conditions....

  17. Modification of a Colliculo-thalamocortical Mouse Brain Slice, Incorporating 3-D printing of Chamber Components and Multi-scale Optical Imaging.

    Science.gov (United States)

    Slater, Bernard J; Fan, Anthony Y; Stebbings, Kevin A; Saif, M Taher A; Llano, Daniel A

    2015-01-01

    The ability of the brain to process sensory information relies on both ascending and descending sets of projections. Until recently, the only way to study these two systems and how they interact has been with the use of in vivo preparations. Major advances have been made with acute brain slices containing the thalamocortical and cortico-thalamic pathways in the somatosensory, visual, and auditory systems. With key refinements to our recent modification of the auditory thalamocortical slice(1), we are able to more reliably capture the projections between most of the major auditory midbrain and forebrain structures: the inferior colliculus (IC), medial geniculate body (MGB), thalamic reticular nucleus (TRN), and the auditory cortex (AC). With portions of all these connections retained, we are able to answer detailed questions that complement the questions that can be answered with in vivo preparations. The use of flavoprotein autofluorescence imaging enables us to rapidly assess connectivity in any given slice and guide the ensuing experiment. Using this slice in conjunction with recording and imaging techniques, we are now better equipped to understand how information processing occurs at each point in the auditory forebrain as information ascends to the cortex, and the impact of descending cortical modulation. 3-D printing to build slice chamber components permits double-sided perfusion and broad access to networks within the slice and maintains the widespread connections key to fully utilizing this preparation. PMID:26437382

  18. Regulation of dopamine synthesis and release in striatal and prefrontal cortical brain slices

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, M.E.

    1986-01-01

    Brain slices were used to investigate the role of nerve terminal autoreceptors in modulating dopamine (DA) synthesis and release in striatum and prefrontal cortex. Accumulation of dihydroxyphenylalanine (DOPA) was used as an index of tyrosine hydroxylation in vitro. Nomifensine, a DA uptake blocker, inhibited DOPA synthesis in striatal but not prefrontal slices. This effect was reversed by the DA antagonist sulpiride, suggesting it involved activation of DA receptors by elevated synaptic levels of DA. The autoreceptor-selective agonist EMD-23-448 also inhibited striatal but not prefrontal DOPA synthesis. DOPA synthesis was stimulated in both brain regions by elevated K/sup +/, however only striatal synthesis could be further enhanced by sulpiride. DA release was measured by following the efflux of radioactivity from brain slices prelabeled with (/sup 3/H)-DA. EMD-23-448 and apomorphine inhibited, while sulpiride enhanced, the K/sup +/-evoked overflow of radioactivity from both striatal and prefrontal cortical slices. These findings suggest that striatal DA nerve terminals possess autoreceptors which modulate tyrosine hydroxylation as well as autoreceptors which modulate release. Alternatively, one site may be coupled to both functions through distinct transduction mechanisms. In contrast, autoreceptors on prefrontal cortical terminals appear to regulate DA release but not DA synthesis.

  19. Functional imaging of single synapses in brain slices.

    Science.gov (United States)

    Oertner, Thomas G

    2002-11-01

    The strength of synaptic connections in the brain is not fixed, but can be modulated by numerous mechanisms. Traditionally, electrophysiology has been used to characterize connections between neurons. Electrophysiology typically reports the activity of populations of synapses, while most mechanisms of plasticity are thought to operate at the level of single synapses. Recently, two-photon laser scanning microscopy has enabled us to perform optical quantal analysis of individual synapses in intact brain tissue. Here we introduce the basic principle of the two-photon microscope and discuss its main differences compared to the confocal microscope. Using calcium imaging in dendritic spines as an example, we explain the advantages of simultaneous dual-dye imaging for quantitative calcium measurements and address two common problems, dye saturation and background fluorescence subtraction.

  20. Dehydroevodiamine attenuates calyculin A-induced tau hyperphosphorylation in rat brain slices

    Institute of Scientific and Technical Information of China (English)

    Jiang FANG; Rong LIU; Qing TIAN; Xiao-ping HONG; Shao-hui WANG; Fu-yuan CAO; Xi-ping PAN; Jian-zhi WANG

    2007-01-01

    Aim:This study was to investigate the effect of dehydroevodiamine (DHED) on Alzheimer's disease (AD)-like tan hyperphosphorylation induced by calyculin A (CA),an inhibitor of protein phosphatase (PP)-2A and PP-1,and the involvement of PP-2A in metabolically competent rat brain slices. Methods:Rat brain slices were pre-incubated at 33 ℃ in the presence (10,100,and 200 μmol/L,respectively)or absence of DHED for 1 h. Then,CA 0.1 μmol/L was added and the slices were treated for another 2 h. Western blotting and/or immunohistochemistry were used to measure the phosphorylation level of tau and PP-2A. Results:CA treatment could remarkably increase the immunoreactivity of pS262 and decrease the staining of Tan-1,representing tau hyperphosphorylation at Ser262 (pS262) and Ser198/199/202 (Tau-1,as the antibody reacts with unphosphorylated tau,therefore,decreased staining represents increased phosphorylation). Pre-incubation of the brain slices with DHED could efficiently attenuate the CA-induced tan hyperphosphorylation at the above AD-related sites. Additionally,DHED also decreased the basal phosphorylation level of tan at Ser396,although CA failed to induce tan hyperphosphorylation at this site. Furthermore,CA treatment induced an increased level of Tyr307-phosphorylated PP-2A,which represents inactivation of the phosphatase,whereas DHED arrested the elevation of the inhibitory modification of PP-2A. Conclusion:DHED can attenuate CA-induced tau hyperphosphorylation at multiple AD-related sites in metabolically active rat brain slices. The underlying mechanism may involve a decreased inhibitory phosphorylation of PP-2A at Tyr307.AcknowledgementsWe thank Dr Khalid IQBAL,Dr Inge GRUNDKE-IQBAL,Dr Cheng-xin GONG,and Dr Fei LIU at New York State Institute for Basic Research for technical support.

  1. Rat brain slices produce and liberate kynurenic acid upon exposure to L-kynurenine

    DEFF Research Database (Denmark)

    Turski, W A; Gramsbergen, J B; Traitler, H;

    1989-01-01

    The incorporation of L-kynurenine (L-KYN) into kynurenic acid (KYNA) was examined in rat brain slices. KYNA was measured in the slices and in the incubation medium after purification by ion-exchange and HPLC chromatography. In pilot experiments, the formation of KYNA was confirmed by gas chromato......The incorporation of L-kynurenine (L-KYN) into kynurenic acid (KYNA) was examined in rat brain slices. KYNA was measured in the slices and in the incubation medium after purification by ion-exchange and HPLC chromatography. In pilot experiments, the formation of KYNA was confirmed by gas....... Neither deletion of Ca2+ or Mg2+ nor addition of 20 mM Mg2+ had any effect. However, KYNA production was significantly attenuated in the absence of Cl- or in the presence of 50 mM K+ in the incubation medium. In Na+-free medium, the production of KYNA from L-KYN was increased by 30%.(ABSTRACT TRUNCATED...

  2. Towards 1H-MRSI of the human brain at 7T with slice-selective adiabatic refocusing pulses.

    NARCIS (Netherlands)

    Scheenen, T.W.J.; Heerschap, A.; Klomp, D.W.J.

    2008-01-01

    OBJECTIVE: To explore the possibilities of proton spectroscopic imaging (1H-MRSI) of the human brain at 7 Tesla with adiabatic refocusing pulses. MATERIALS AND METHODS: A combination of conventional slice selective excitation and two pairs of slice selective adiabatic refocusing pulses (semi-LASER)

  3. Intersection-based registration of slice stacks to form 3D images of the human fetal brain

    DEFF Research Database (Denmark)

    Kim, Kio; Hansen, Mads Fogtmann; Habas, Piotr;

    2008-01-01

    Clinical fetal MR imaging of the brain commonly makes use of fast 2D acquisitions of multiple sets of approximately orthogonal 2D slices. We and others have previously proposed an iterative slice-to-volume registration process to recover a geometrically consistent 3D image. However, these approac...

  4. Brain tumor segmentation in MR slices using improved GrowCut algorithm

    Science.gov (United States)

    Ji, Chunhong; Yu, Jinhua; Wang, Yuanyuan; Chen, Liang; Shi, Zhifeng; Mao, Ying

    2015-12-01

    The detection of brain tumor from MR images is very significant for medical diagnosis and treatment. However, the existing methods are mostly based on manual or semiautomatic segmentation which are awkward when dealing with a large amount of MR slices. In this paper, a new fully automatic method for the segmentation of brain tumors in MR slices is presented. Based on the hypothesis of the symmetric brain structure, the method improves the interactive GrowCut algorithm by further using the bounding box algorithm in the pre-processing step. More importantly, local reflectional symmetry is used to make up the deficiency of the bounding box method. After segmentation, 3D tumor image is reconstructed. We evaluate the accuracy of the proposed method on MR slices with synthetic tumors and actual clinical MR images. Result of the proposed method is compared with the actual position of simulated 3D tumor qualitatively and quantitatively. In addition, our automatic method produces equivalent performance as manual segmentation and the interactive GrowCut with manual interference while providing fully automatic segmentation.

  5. Characteristics of Spontaneous and Evoked EPSPs Recorded From Dentate Spiny Hilar Cells in Rat Hippocampal Slices

    OpenAIRE

    Scharfman, Helen E.

    1993-01-01

    Excitation of the spiny subtype of hilar neurons in the fascia dentata was characterized by intracellular recording from hilar cells in hippocampal slices. Stimulation of the outer molecular layer was used to activate the perforant path. Evoked responses were examined, as well as the large spontaneous excitatory potentials that are a distinctive characteristic of spiny hilar cells.Excitatory potentials that occurred spontaneously, as well as those that occurred in response to outer molecular ...

  6. Improvement of the in vitro recordings in cortical slices by using customized flexible neuroprobes

    Directory of Open Access Journals (Sweden)

    Xavi Illa

    2015-04-01

    Full Text Available We have explored the feasibility of improving the quality of multiple recordings from spontaneously oscillating cortical slices. With that purpose we have taken advantage of the advances performed in the development of flexible neuproprobes, either fabricated on polyimide, SU-8, PDMS or parylene (Hassler et al. 2011. With these materials the contact between the electrodes and the tissue is enhanced with respect to the neuroprobes fabricated on rigid substrates, such as silicon or pyrex. However, we had to find a compromise between the necessity to achieve a good contact between the electrode and the slice and the need to allow the flow of oxygenated solution to the slice to maintain its healthy state when using flexible neuroprobes. To overcome this limitation, we have designed, fabricated and characterized a 16-electrode flexible neuroprobe that allocates an array of holes in its sensing area. This neuroprobe has been developed using SU-8 negative photoresist as a substrate material in the clean room facilities of the IMB-CNM. In particular, the neuroprobes have been fabricated following the process described in a previous article from the authors (Guimerà et al. 2013; using silicon wafers with an aluminum sacrificial layer as a support for the fabrication process. Then, the neuroprobes were released from the wafer by an anodic dissolution of the aluminum layer (Metz et al. 2005. In order to validate the usability of the fabricated device, the neuroprobes were used to record spontaneous slow oscillations to study the wave propagation along the cortical networks while manipulating them by means of pharmacological drugs or electric fields. We conclude that the perforated devices provide substantial improvement in the adherence of the electrodes to the tissue, on the mechanical stability of the recordings, and in the healthiness of the slices.

  7. Parkia biglobosa Improves Mitochondrial Functioning and Protects against Neurotoxic Agents in Rat Brain Hippocampal Slices

    Directory of Open Access Journals (Sweden)

    Kayode Komolafe

    2014-01-01

    Full Text Available Objective. Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria. Methods. Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL or catechin (1, 5, or 10 µg/mL for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm were also determined. Results. PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na+, K+-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin. Conclusion. The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

  8. Coculture System with an Organotypic Brain Slice and 3D Spheroid of Carcinoma Cells

    Science.gov (United States)

    Chuang, Han-Ning; Lohaus, Raphaela; Hanisch, Uwe-Karsten; Binder, Claudia

    2013-01-01

    Patients with cerebral metastasis of carcinomas have a poor prognosis. However, the process at the metastatic site has barely been investigated, in particular the role of the resident (stromal) cells. Studies in primary carcinomas demonstrate the influence of the microenvironment on metastasis, even on prognosis1,2. Especially the tumor associated macrophages (TAM) support migration, invasion and proliferation3. Interestingly, the major target sites of metastasis possess tissue-specific macrophages, such as Kupffer cells in the liver or microglia in the CNS. Moreover, the metastatic sites also possess other tissue-specific cells, like astrocytes. Recently, astrocytes were demonstrated to foster proliferation and persistence of cancer cells4,5. Therefore, functions of these tissue-specific cell types seem to be very important in the process of brain metastasis6,7. Despite these observations, however, up to now there is no suitable in vivo/in vitro model available to directly visualize glial reactions during cerebral metastasis formation, in particular by bright field microscopy. Recent in vivo live imaging of carcinoma cells demonstrated their cerebral colonization behavior8. However, this method is very laborious, costly and technically complex. In addition, these kinds of animal experiments are restricted to small series and come with a substantial stress for the animals (by implantation of the glass plate, injection of tumor cells, repetitive anaesthesia and long-term fixation). Furthermore, in vivo imaging is thus far limited to the visualization of the carcinoma cells, whereas interactions with resident cells have not yet been illustrated. Finally, investigations of human carcinoma cells within immunocompetent animals are impossible8. For these reasons, we established a coculture system consisting of an organotypic mouse brain slice and epithelial cells embedded in matrigel (3D cell sphere). The 3D carcinoma cell spheres were placed directly next to the brain

  9. Towards 1H-MRSI of the human brain at 7T with slice-selective adiabatic refocusing pulses

    OpenAIRE

    Scheenen, Tom W. J.; Heerschap, Arend; Dennis W.J. Klomp

    2008-01-01

    Objective To explore the possibilities of proton spectroscopic imaging (1H-MRSI) of the human brain at 7 Tesla with adiabatic refocusing pulses. Materials and methods A combination of conventional slice selective excitation and two pairs of slice selective adiabatic refocusing pulses (semi-LASER) results in the formation of an echo from a localized volume. Depending on the used radio frequency (rf) coil efficiency and available rf power, the duration of the adiabatic full passage pulses (AFPs...

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  11. Microelectrode array recordings of excitability of low Mg2+-induced acute hippocampal slices

    Institute of Scientific and Technical Information of China (English)

    Fan Yang; Xinwei Gong; Haiqing Gong; Puming Zhang; Peiji Liang; Qinchi LU

    2010-01-01

    Neuronal connections can be detected by neuronal network discharges in hippocampal neurons cultured on multi-electrodes.However,the multi-electrode-array(MEA)has not been widely used in hippocampal slice culture studies focused on epilepsy.The present study induced spontaneous synchronous epileptiform activity using low Mg2+artificial cerebrospinal fluid on acute hippocampal slices to record hippocampal discharges with MEA.Results showed that burst duration and average number of spikes in a burst were significantly greater in the CA3 compared with dentate gyrus and CA1 areas.In Schaffer cut-off group,CA1 area discharges disappeared,but synchronous discharges remained in the CA3 area.Moreover,synchronous discharge frequency in the Schaffer cut-off group was similar to control.However,burst duration and average number of spikes in a burst were significantly decreased compared with control(P < 0.05).Results demonstrated that highest neuronal excitability occurred in the CA3 area,and synchronous discharges induced by low Mg2+originated from the CA3 region.

  12. Analysis of acute brain slices by electron microscopy: a correlative light-electron microscopy workflow based on Tokuyasu cryo-sectioning.

    Science.gov (United States)

    Loussert Fonta, Celine; Leis, Andrew; Mathisen, Cliff; Bouvier, David S; Blanchard, Willy; Volterra, Andrea; Lich, Ben; Humbel, Bruno M

    2015-01-01

    Acute brain slices are slices of brain tissue that are kept vital in vitro for further recordings and analyses. This tool is of major importance in neurobiology and allows the study of brain cells such as microglia, astrocytes, neurons and their inter/intracellular communications via ion channels or transporters. In combination with light/fluorescence microscopies, acute brain slices enable the ex vivo analysis of specific cells or groups of cells inside the slice, e.g. astrocytes. To bridge ex vivo knowledge of a cell with its ultrastructure, we developed a correlative microscopy approach for acute brain slices. The workflow begins with sampling of the tissue and precise trimming of a region of interest, which contains GFP-tagged astrocytes that can be visualised by fluorescence microscopy of ultrathin sections. The astrocytes and their surroundings are then analysed by high resolution scanning transmission electron microscopy (STEM). An important aspect of this workflow is the modification of a commercial cryo-ultramicrotome to observe the fluorescent GFP signal during the trimming process. It ensured that sections contained at least one GFP astrocyte. After cryo-sectioning, a map of the GFP-expressing astrocytes is established and transferred to correlation software installed on a focused ion beam scanning electron microscope equipped with a STEM detector. Next, the areas displaying fluorescence are selected for high resolution STEM imaging. An overview area (e.g. a whole mesh of the grid) is imaged with an automated tiling and stitching process. In the final stitched image, the local organisation of the brain tissue can be surveyed or areas of interest can be magnified to observe fine details, e.g. vesicles or gold labels on specific proteins. The robustness of this workflow is contingent on the quality of sample preparation, based on Tokuyasu's protocol. This method results in a reasonable compromise between preservation of morphology and maintenance of

  13. Nimodipine enhances neurite outgrowth in dopaminergic brain slice co-cultures.

    Science.gov (United States)

    Sygnecka, Katja; Heine, Claudia; Scherf, Nico; Fasold, Mario; Binder, Hans; Scheller, Christian; Franke, Heike

    2015-02-01

    Calcium ions (Ca(2+)) play important roles in neuroplasticity and the regeneration of nerves. Intracellular Ca(2+) concentrations are regulated by Ca(2+) channels, among them L-type voltage-gated Ca(2+) channels, which are inhibited by dihydropyridines like nimodipine. The purpose of this study was to investigate the effect of nimodipine on neurite growth during development and regeneration. As an appropriate model to study neurite growth, we chose organotypic brain slice co-cultures of the mesocortical dopaminergic projection system, consisting of the ventral tegmental area/substantia nigra and the prefrontal cortex from neonatal rat brains. Quantification of the density of the newly built neurites in the border region (region between the two cultivated slices) of the co-cultures revealed a growth promoting effect of nimodipine at concentrations of 0.1μM and 1μM that was even more pronounced than the effect of the growth factor NGF. This beneficial effect was absent when 10μM nimodipine were applied. Toxicological tests revealed that the application of nimodipine at this higher concentration slightly induced caspase 3 activation in the cortical part of the co-cultures, but did neither affect the amount of lactate dehydrogenase release or propidium iodide uptake nor the ratio of bax/bcl-2. Furthermore, the expression levels of different genes were quantified after nimodipine treatment. The expression of Ca(2+) binding proteins, immediate early genes, glial fibrillary acidic protein, and myelin components did not change significantly after treatment, indicating that the regulation of their expression is not primarily involved in the observed nimodipine mediated neurite growth. In summary, this study revealed for the first time a neurite growth promoting effect of nimodipine in the mesocortical dopaminergic projection system that is highly dependent on the applied concentrations. PMID:25447789

  14. Effects of the pyrethroid insecticide, deltamethrin, on respiratory modulated hypoglossal motoneurons in a brain stem slice from newborn mice

    DEFF Research Database (Denmark)

    Rekling, J C; Theophilidis, G

    1995-01-01

    We have studied the action of deltamethrin on respiratory modulated hypoglossal motoneurons in a brain stem slice from newborn mice. Deltamethrin depolarized the hypoglossal motoneurons, increased the background synaptic noise and reduced the frequency and amplitude of current elicited action pot...

  15. Erratum to "Noise-induced changes of neuronal spontaneous activity in mice inferior colliculus brain slices".

    Science.gov (United States)

    Basta, Dietmar; Ernst, Arne

    2005-02-01

    The inferior colliculus (IC) in vivo is reportedly subject to a noise-induced decrease of GABA-related inhibitory synaptic transmission accompanied by an amplitude increase of auditory evoked responses, a widening of tuning curves and a higher neuronal discharge rate at suprathreshold levels. However, other in vivo experiments which demonstrated constant neuronal auditory thresholds or unchanged spontaneous activity in the IC after noise exposure did not confirm those findings. Perhaps this can be the result of complex noise-induced interactions between different central auditory structures. It was, therefore, the aim of the present study to investigate the effects of noise exposure on the spontaneous electrical activity of single neurons in a slice preparation of the isolated mouse IC. Normal hearing mice were exposed to noise (10 kHz center frequency at 115 dB SPL for 3 h) at the age of 21 days under anesthesia (Ketamin/Rompun 10:1). After one week, auditory brainstem response (ABR) recordings and extracellular single-unit recordings from spontaneously active neurons within the IC slice were performed in noise-exposed and in normal hearing control mice. Noise-exposed animals showed a significant ABR threshold shift in the whole tested frequency range and a significant lower neuronal spontaneous activity in all investigated isofrequency laminae compared to controls. In both groups, the firing rate of 80% of IC neurons (approximately) increased significantly during the application of the GABA(A) receptor antagonist Bicucullin (10 microM). The present findings demonstrate a noise-related modulation of spontaneous activity in the IC, which possibly contribute to the generation of noise-induced tinnitus and hearing loss.

  16. Noise-induced changes of neuronal spontaneous activity in mice inferior colliculus brain slices.

    Science.gov (United States)

    Basta, Dietmar; Ernest, Arne

    2004-09-30

    The inferior colliculus (IC) in vivo is reportedly subject to a noise-induced decrease of GABA-related inhibitory synaptic transmission accompanied by an amplitude increase of auditory evoked responses, a widening of tuning curves and a higher neuronal discharge rate at suprathreshold levels. However, other in vivo experiments which demonstrated constant neuronal auditory thresholds or unchanged spontaneous activity in the IC after noise exposure did not confirm those findings. Perhaps this can be the result of complex noise-induced interactions between different central auditory structures. It was, therefore, the aim of the present study to investigate the effects of noise exposure on the spontaneous electrical activity of single neurons in a slice preparation of the isolated mouse IC. Normal hearing mice were exposed to noise (10 kHz center frequency at 115 dB SPL for 3 h) at the age of 21 days under anesthesia (Ketamin/Rompun 10:1). After one week, auditory brainstem response (ABR) recordings and extracellular single-unit recordings from spontaneously active neurons within the IC slice were performed in noise-exposed and in normal hearing control mice. Noise-exposed animals showed a significant ABR threshold shift in the whole tested frequency range and a significant lower neuronal spontaneous activity in all investigated isofrequency laminae compared to controls. In both groups, the firing rate of 80% of IC neurons (approximately) increased significantly during the application of the GABA(A) receptor antagonist Bicucullin (10 microM). The present findings demonstrate a noise-related modulation of spontaneous activity in the IC, which possibly contribute to the generation of noise-induced tinnitus and hearing loss.

  17. Mechanistic studies of antibody mediated clearance of tau aggregates using an ex vivo brain slice model

    Directory of Open Access Journals (Sweden)

    Pavan eKrishnamurthy

    2011-10-01

    Full Text Available Recent studies have shown that immunotherapy clears amyloid beta (A plaques and reduces A levels in mouse models of Alzheimer’s disease (AD, as well as in AD patients. Tangle pathology is also relevant for the neurodegeneration in AD, and our studies have shown that active immunization with an AD related phospho-tau peptide reduces aggregated tau within the brain and slows the progression of tauopathy-induced behavioural impairments. Thus, clearance of neurofibrillary tangles and/or their precursors may reduce synaptic and neuronal loss associated with AD and other tauopathies. So far the mechanisms involved in antibody-mediated clearance of tau pathology are yet to be elucidated. In this study we have used a mouse brain slice model to examine the uptake and localization of FITC labeled anti-tau antibodies. Confocal microscopy analysis showed that the FITC labelled anti-tau antibody co-stained with phosphorylated tau, had a perinuclear appearance and co-localised with markers of the endosomal/lysosomal pathway. Additionally, tau and FITC IgG were found together in an enriched lysosome fraction. In summary, antibody-mediated clearance of intracellular tau aggregates appears to occur via the lysosomal pathway.

  18. Preparation of human formalin-fixed brain slices for electron microscopic investigations.

    Science.gov (United States)

    Krause, Martin; Brüne, Martin; Theiss, Carsten

    2016-07-01

    Ultra-structural analysis of human post-mortem brain tissue is important for investigations into the pathomechanism of neuropsychiatric disorders, especially those lacking alternative models of studying human-specific morphological features. For example, Von Economo Neurons (VENs) mainly located in the anterior cingulate cortex and in the anterior part of the insula, which seem to play a role in a variety of neuropsychiatric conditions, including frontotemporal dementia, autism and schizophrenia, can hardly be studied in nonhuman animals. Accordingly, little is known about the ultra-structural alterations of these neurons, though important research using qualitative stereological methods has revealed that protein expression of the VENs assigns them a role in immune function. Formaldehyde, which is the most common fixative in human pathology, interferes with the immunoreactivity of the tissue, possibly leading to unreliable results. Therefore, a method for ultra-structural investigations independent of antigenic properties of the fixated tissue is needed. Here, we propose an approach using electron microscopy to examine cytoskeletal structures, synapses and mitochondria in these cells. We also show that our methodology is able to keep tissue consumption to a minimum, while still allowing for the specimens to be handled with ease by using agar embedded slices in contrast to blocks for the embedding procedure. Accordingly, a stepwise protocol utilising 60μm thick human post mortem brain sections for electron microscopic ultra-structural investigations is presented. PMID:27136748

  19. Organotypic slice cultures from rat brain tissue: a new approach for Naegleria fowleri CNS infection in vitro.

    Science.gov (United States)

    Gianinazzi, C; Schild, M; Müller, N; Leib, S L; Simon, F; Nuñez, S; Joss, P; Gottstein, B

    2005-12-01

    The free-living amoeba Naegleria fowleri is the aetiological agent of primary amoebic meningoencephalitis (PAM), a disease leading to death in the vast majority of cases. In patients suffering from PAM, and in corresponding animal models, the brain undergoes a massive inflammatory response, followed by haemorrhage and severe tissue necrosis. Both, in vivo and in vitro models are currently being used to study PAM infection. However, animal models may pose ethical issues, are dependent upon availability of specific infrastructural facilities, and are time-consuming and costly. Conversely, cell cultures lack the complex organ-specific morphology found in vivo, and thus, findings obtained in vitro do not necessarily reflect the situation in vivo. The present study reports infection of organotypic slice cultures from rat brain with N. fowleri and compares the findings in this culture system with in vivo infection in a rat model of PAM, that proved complementary to that of mice. We found that brain morphology, as present in vivo, is well retained in organotypic slice cultures, and that infection time-course including tissue damage parallels the observations in vivo in the rat. Therefore, organotypic slice cultures from rat brain offer a new in vitro approach to study N. fowleri infection in the context of PAM.

  20. Strain fields in histological slices of brain tissue determined by synchrotron radiation-based micro computed tomography.

    Science.gov (United States)

    Germann, Marco; Morel, Anne; Beckmann, Felix; Andronache, Adrian; Jeanmonod, Daniel; Müller, Bert

    2008-05-15

    Accurate knowledge of the morphology of the human brain is required for minimally or non-invasive surgical interventions. On the (sub-)cellular level, brain tissue is generally characterized using optical microscopy, which allows extracting morphological features with a wide spectrum of staining procedures. The preparation of the histological slices, however, often leads to artifacts resulting in imperfect morphological data. In addition, the generation of 3D data is time-consuming. Therefore, we propose synchrotron radiation-based micro computed tomography (SRmicroCT) avoiding preparation artifacts and giving rise to the 3D morphology of features such as gray and white matter on the micrometer level. One can differentiate between white and gray matter without any staining procedure because of different X-ray absorption values. At the photon energy of 10keV, the white matter exhibits the absorption of 5.08 cm(-1), whereby the value for the gray matter corresponds to 5.25 cm(-1). The tomography data allow quantifying the local strains in the histological images using registration algorithms. The deformation of histological slices compared to the SRmicroCT in a 2D-2D registration leads to values of up to 6.3%. Mean deformation values for the Nissl-stained slices are determined to about 1%, whereas the myelin-stained slices yield slightly higher values than 2%.

  1. The relationship between decorrelation time and sample thickness in acute rat brain tissue slices (Conference Presentation)

    Science.gov (United States)

    Brake, Joshua; Jang, Mooseok; Yang, Changhuei

    2016-03-01

    The optical opacity of biological tissue has long been a challenge in biomedical optics due to the strong scattering nature of tissue in the optical regime. While most conventional optical techniques attempt to gate out multiply scattered light and use only unscattered light, new approaches in the field of wavefront shaping exploit the time reversible symmetry of optical scattering in order to focus light inside or through scattering media. While these approaches have been demonstrated effectively on static samples, it has proven difficult to apply them to dynamic biological samples since even small changes in the relative positions of the scatterers within will cause the time symmetry that wavefront shaping relies upon to decorrelate. In this paper we investigate the decorrelation curves of acute rat brain slices for thicknesses in the range 1-3 mm (1/e decorrelation time on the order of seconds) using multi-speckle diffusing wave spectroscopy (MSDWS) and compare the results with theoretical predictions. The results of this study demonstrate that the 1/L^2 relationship between decorrelation time and thickness predicted by diffusing wave spectroscopy provides a good rule of thumb for estimating how the decorrelation of a sample will change with increasing thickness. Understanding this relationship will provide insight to guide the future development of biophotonic wavefront shaping tools by giving an estimate of how fast wavefront shaping systems need to operate to overcome the dynamic nature of biological samples.

  2. Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs?

    DEFF Research Database (Denmark)

    Hansen, Suzanne L.; Sterjev, Zoran; Werngreen, Marie;

    2012-01-01

    The cortical wedge is a commonly applied model for in vitro screening of new antiepileptic drugs (AEDs) and has been extensively used in characterization of well-known AEDs. However, the predictive validity of this model as a screening model has been questioned as, e.g., carbamazepine has been...... reported to lack effect in this model. The neuroplastic changes induced in acute and chronic animal models of epilepsy are known to affect the pharmacological profile of AEDs in vivo. Hence, we investigated whether brain slices from pentylenetetrazole (PTZ)-kindled animals could provide a more predictive...... screening model for AEDs. To this end, we compared the in vitro and in vivo pharmacological profile of several selected AEDs (phenobarbital, phenytoin, tiagabine, fosphenytoin, valproate, and carbamazepine) along with citalopram using the PTZ-kindled model and brain slices from naïve, saline...

  3. OBSERVATION OF THE ALTERNATION OF NUCLEIC ACID IN BRAIN SLICE AND NEURONS BY CONFOCAL LASER SCANNING MICROSCOPY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Confocal laser scanning microscope is one of the most important biomedicine Altus instru ment〔1〕. It has the characteristics of high sensitivity for detecting the stereo structure, and can scan a few hundreds of micrometer-thick tissue. It may get graphs of intracyte or tissue with uninvading stage scan and is named "cell CT". In this study, the nucleic acid alterations of whole brain slice was investigated with this technique after the formation of LTP.

  4. Brain perfusion CT for acute stroke using a 256-slice CT: improvement of diagnostic information by large volume coverage

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, F. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Institut fuer Radiologie, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Muenchen (Germany); Muenzel, D.; Meier, R.; Rummeny, E.J.; Huber, A. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Poppert, H. [Technical University, Department of Neurology, Klinikum rechts der Isar, Munich (Germany)

    2011-09-15

    To compare a 256-slice CT with a simulated standard CT for brain CT perfusion (CTP). CTP was obtained in 51 patients using a 256-slice CT (128 detector rows, flying z-focus, 8-cm detector width, 80 kV, 120mAs, 20 measurements, 1 CT image/2.5 s). Signal-to-noise ratios (SNR) were compared in grey and white matter. Perfusion maps were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in hypoperfused areas and corresponding contralateral regions. Two reconstructed 10-mm slices for simulation of a standard CT (SDCT) were compared with the complete data sets (large-volume CT, LVCT). Adequate image quality was achieved in 50/51 cases. SNR were significantly different in grey and white matter. A perfusion deficit was present in 27 data sets. Differences between the hypoperfusions and the control regions were significant for MTT and CBF, but not for CBV. Three lesions were missed by SDCT but detected by LVCT; 24 lesions were covered incompletely by SDCT, and 6 by LVCT. 21 lesions were detected completely by LVCT, but none by SDCT. CTP imaging of the brain using an increased detector width can detect additional ischaemic lesions and cover most ischaemic lesions completely. (orig.)

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

    Science.gov (United States)

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

    1990-10-01

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

  6. Protective effect of bone marrow-derived mesenchymal stem cells on dopaminergic neurons against 1-methyl-4-phenylpyridinium ion-induced neurotoxicity in rat brain slices

    Institute of Scientific and Technical Information of China (English)

    Lirong Jin; Zhen Hong; Chunjiu Zhong; Yang Wang

    2009-01-01

    BACKGROUND: To date, the use of bone marrow-derived mesenchymal stem cells (MSCs) for the treatment of Parkinson's disease have solely focused on in vivo animal models. Because of the number of influencing factors, it has been difficult to determine a consistent outcome. OBJECTIVE: To establish an injury model in brain slices of substantia nigra and striatum using 1-methyl-4-phenylpytidinium ion (MPP+), and to investigate the effect of MSCs on dopaminergic neurons following MPP+ induced damage.DESIGN, TIME AND SETTING: An in vitro, randomized, controlled, animal experiment using immunohistochemistry was performed at the Laboratory of the Department of Anatomy, Fudan University between January 2004 and December 2006.MATERIALS: Primary MSC cultures were obtained from femurs and tibias of adult Sprague Dawley rats. Organotypic brain slices were isolated from substantia nigra and striatum of 1-day-old Sprague Dawley rat pups. Monoclonal antibodies for tyrosine hydroxylase (TH, 1:5 000) were from Santa Cruz (USA); goat anti-rabbit IgG antibodies labeled with FITC were from Boster Company (China).METHODS: Organotypic brain slices were cultured for 5 days in whole culture medium supplemented with 50% DMEM, 25% equine serum, and 25% Tyrode's balanced salt solution. The medium was supplemented with 5 μg/mL Ara-C, and the culture was continued for an additional 5 days. The undergrowth of brain slices was discarded at day 10. Eugonic brain slices were cultured with basal media for an additional 7 days. The brain slices were divided into three groups: control, MPP+ exposure, and co-culture. For the MPP+ group, MPP+ (30 μmol/L) was added to the media at day 17 and brain slices were cultured for 4 days, followed by control media. For the co-culture group, the MPP+ injured brain slices were placed over MSCs in the well and were further cultured for 7 days.MAIN OUTCOME MEASURES: After 28 days in culture, neurite outgrowth was examined in the brain slices under phase

  7. Long-term GnRH-induced gonadotropin secretion in a novel hypothalamo-pituitary slice culture from tilapia brain.

    Science.gov (United States)

    Bloch, Corinne L; Kedar, Noa; Golan, Matan; Gutnick, Michael J; Fleidervish, Ilya A; Levavi-Sivan, Berta

    2014-10-01

    Organotypic cultures, prepared from hypothalamo-pituitary slices of tilapia, were developed to enable long-term study of secretory cells in the pituitary of a teleost. Values of membrane potential at rest were similar to those recorded from acute slices, and cells presented similar spontaneous spikes and spikelets. Some cells also exhibited slow spontaneous oscillations in membrane potential, which may be network-driven. Long-term (6days) continuous exposure to GnRH induced increases in LH and FSH secretion. FSH levels reached the highest levels after 24h of exposure to GnRH, and the highest secretion of LH was observed in days 4 and 5 of the experiment. Since slices were viable for several weeks in culture, maintaining the original cytoarchitecture, electrical membrane properties and the ability to secrete hormones in response to exogenous GnRH, this technique is ideal for studying the mechanisms regulating cell-to-cell communication under conditions resembling the in vivo tissue organization.

  8. GABAB receptor modulation of adenylate cyclase activity in rat brain slices.

    OpenAIRE

    Hill, D R

    1985-01-01

    An investigation of the effects of gamma-aminobutyric acid (GABA) and the selective GABAB receptor agonist, baclofen, on basal and stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) levels in slices of rat cerebral cortex has been carried out. Neither GABA nor baclofen produced any significant change in basal cyclic AMP levels. By contrast noradrenaline and forskolin both produced dose-dependent increases in cellular cyclic AMP accumulation. GABA (in the presence of nipecotic acid) ...

  9. [3H] glycogen hydrolysis in brain slices: responses to meurotransmitters and modulation of noradrenaline receptors

    International Nuclear Information System (INIS)

    Different agents have been investigated for their effects on [3H] glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration-dependent glycogenesis. [3H] glycogen hydrolysis induced by noradrenaline appears to be mediated by beta-adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis. Lower concentrations of noradrenaline were necessary for [3H] glycogen hydrolysis (ECsub(50) 0.5μM) than for stimulation of cyclic AMP accumulation (ECsub(50) = 8μM). After subchronic reserpine treatment the concentration-response curve to noradrenaline was significantly shifted to the left (ECsub(50) = 0.09 +- 0.02 μM as compared with 0.49 +- 0.08μM in saline-pretreated mice) without modifications of either the basal [3H] glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP-induced glycogenolytic response. In addition to noradrenaline, clear concentration-dependent [3H] glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [3H] glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K+ provoked a nearly total [3H] glycogen hydrolysis. (author)

  10. Dual activities of the anti-cancer drug candidate PBI-05204 provide neuroprotection in brain slice models for neurodegenerative diseases and stroke

    OpenAIRE

    Van Kanegan, Michael J.; Dunn, Denise E.; Kaltenbach, Linda S.; Bijal Shah; Dong Ning He; Daniel D. McCoy; Peiying Yang; Jiangnan Peng; Li Shen; Lin Du; Cichewicz, Robert H.; Newman, Robert A; Lo, Donald C.

    2016-01-01

    We previously reported neuroprotective activity of the botanical anti-cancer drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, in brain slice and in vivo models of ischemic stroke. We showed that one component of this neuroprotective activity is mediated through its principal cardiac glycoside constituent, oleandrin, via induction of the potent neurotrophic factor brain-derived neurotrophic factor (BDNF). However, we also noted that the concentration-relation for PBI-0...

  11. Cytosolic NADH-NAD+ Redox Visualized in Brain Slices by Two-Photon Fluorescence Lifetime Biosensor Imaging

    Science.gov (United States)

    Mongeon, Rebecca; Venkatachalam, Veena

    2016-01-01

    Abstract Aim: Cytosolic NADH-NAD+ redox state is central to cellular metabolism and a valuable indicator of glucose and lactate metabolism in living cells. Here we sought to quantitatively determine NADH-NAD+ redox in live cells and brain tissue using a fluorescence lifetime imaging of the genetically-encoded single-fluorophore biosensor Peredox. Results: We show that Peredox exhibits a substantial change in its fluorescence lifetime over its sensing range of NADH-NAD+ ratio. This allows changes in cytosolic NADH redox to be visualized in living cells using a two-photon scanning microscope with fluorescence lifetime imaging capabilities (2p-FLIM), using time-correlated single photon counting. Innovation: Because the lifetime readout is absolutely calibrated (in nanoseconds) and is independent of sensor concentration, we demonstrate that quantitative assessment of NADH redox is possible using a single fluorophore biosensor. Conclusion: Imaging of the sensor in mouse hippocampal brain slices reveals that astrocytes are typically much more reduced (with higher NADH:NAD+ ratio) than neurons under basal conditions, consistent with the hypothesis that astrocytes are more glycolytic than neurons. Antioxid. Redox Signal. 25, 553–563. PMID:26857245

  12. Direct Visualization of Neurotransmitters in Rat Brain Slices by Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI - MS)

    Science.gov (United States)

    Fernandes, Anna Maria A. P.; Vendramini, Pedro H.; Galaverna, Renan; Schwab, Nicolas V.; Alberici, Luciane C.; Augusti, Rodinei; Castilho, Roger F.; Eberlin, Marcos N.

    2016-10-01

    Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials. The amino acids γ-aminobutyric (GABA), glutamate, aspartate, serine, as well as acetylcholine, dopamine, and choline were successfully imaged using a commercial DESI source coupled to a hybrid quadrupole-Orbitrap mass spectrometer. The spatial distribution of the analyzed compounds in different brain regions was determined. We conclude that the ambient matrix-free DESI-MSI is suitable for neurotransmitter imaging and could be applied in studies that involve evaluation of imbalances in neurotransmitters levels.

  13. Congener-specific effects of dioxins on neural cell cultures and brain slices

    Energy Technology Data Exchange (ETDEWEB)

    Tiffany-Castiglioni, E.; Hanneman, W.H.; Legare, M.E.; Hong, S.J.; Barhoumi, R.; Burghardt, R.C.; Safe, S. [Texas A and M Univ., College Station, TX (United States)

    1994-12-31

    Recent attention has focused on the neurotoxicity of polychlorinated biphenyls, dibenzofurans, and quaterphenyls and related compounds. The hippocampus may be an important target for neurotoxic compounds because of its role in short-term memory and learning. The authors report preliminary experiments on the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a model for the neurotoxicity of halogenated aromatic hydrocarbons. Exposure of cultured rat hippocampal neutrons and glia to TCDD invoked a rapid concentration dependent increase in intracellular calcium ion concentration as determined by microscopic image analysis of cells noninvasively labeled with fluo-3. This rapid increase was blocked by the addition of EDTA or nifedipine to the external medium. In contrast, the nontoxic congener 1,2,3,4-TCDD was inactive at concentrations up to 10 {micro}m. Other effects of TCDD on cultured neurons and astroglia were measured, including cell-cell communication via gap junctions, which was down-regulated, and cytosolic glutathione content, which was depressed in astroglia. Astroglial cells serve vital roles in regulating the neuronal environment. The authors have also conducted pilot experiments on TCDD effects on synaptic function in hippocampal slices.

  14. Expression of hypoxia-inducible factor 1 alpha and oligodendrocyte lineage gene-1 in cultured brain slices after oxygen-glucose deprivation

    Institute of Scientific and Technical Information of China (English)

    Hong Cui; Weijuan Han; Lijun Yang; Yanzhong Chang

    2013-01-01

    Oligodendrocyte lineage gene-1 expressed in oligodendrocytes may trigger the repair of neuronal myelin impairment, and play a crucial role in myelin repair. Hypoxia-inducible factor 1α, a transcription factor, is of great significance in premature infants with hypoxic-ischemic brain damage. There is little evidence of direct regulatory effects of hypoxia-inducible factor 1α on oligodendrocyte lineage gene-1. In this study, brain slices of Sprague-Dawley rats were cultured and subjected to oxygen-glucose deprivation. Then, slices were transfected with hypoxia-inducible factor 1α or oligodendrocyte lineage gene-1. The expression levels of hypoxia-inducible factor 1α and oligodendrocyte lineage gene-1 were significantly up-regulated in rat brains prior to transfection, as detected by immunohistochemical staining. Eight hours after transfection of slices with hypoxia-inducible factor 1α, oligodendrocyte lineage gene-1 expression was upregulated, and reached a peak 24 hours after transfection. Oligodendrocyte lineage gene-1 transfection induced no significant differences in hypoxia-inducible factor 1α levels in rat brain tissues with oxygen-glucose deprivation. These experimental findings indicate that hypoxia-inducible factor 1α can regulate oligodendrocyte lineage gene-1 expression in hypoxic brain tissue, thus repairing the neural impairment.

  15. Biocompatibility of silicon-based arrays of electrodes coupled to organotypic hippocampal brain slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne Winther; Noraberg, J; Thiébaud, P;

    2001-01-01

    arrays and develop normally with display of normal subfield differentiated susceptibilities to known excito- and neurotoxins. From this it is anticipated that the set-up, designed for recording of electrophysiological parameters, can be used for long-term studies of defined neuronal networks and provide...

  16. Dual activities of the anti-cancer drug candidate PBI-05204 provide neuroprotection in brain slice models for neurodegenerative diseases and stroke.

    Science.gov (United States)

    Van Kanegan, Michael J; Dunn, Denise E; Kaltenbach, Linda S; Shah, Bijal; He, Dong Ning; McCoy, Daniel D; Yang, Peiying; Peng, Jiangnan; Shen, Li; Du, Lin; Cichewicz, Robert H; Newman, Robert A; Lo, Donald C

    2016-01-01

    We previously reported neuroprotective activity of the botanical anti-cancer drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, in brain slice and in vivo models of ischemic stroke. We showed that one component of this neuroprotective activity is mediated through its principal cardiac glycoside constituent, oleandrin, via induction of the potent neurotrophic factor brain-derived neurotrophic factor (BDNF). However, we also noted that the concentration-relation for PBI-05204 in the brain slice oxygen-glucose deprivation (OGD) model is considerably broader than that for oleandrin as a single agent. We thus surmised that PBI-05204 contains an additional neuroprotective component(s), distinct from oleandrin. We report here that neuroprotective activity is also provided by the triterpenoid constituents of PBI-05204, notably oleanolic acid. We demonstrate that a sub-fraction of PBI-05204 (Fraction 0-4) containing oleanolic and other triterpenoids, but without cardiac glycosides, induces the expression of cellular antioxidant gene transcription programs regulated through antioxidant transcriptional response elements (AREs). Finally, we show that Fraction 0-4 provides broad neuroprotection in organotypic brain slice models for neurodegeneration driven by amyloid precursor protein (APP) and tau implicated in Alzheimer's disease and frontotemporal dementias, respectively, in addition to ischemic injury modeled by OGD. PMID:27172999

  17. Stimulant mechanisms of cathinones - effects of mephedrone and other cathinones on basal and electrically evoked dopamine efflux in rat accumbens brain slices.

    Science.gov (United States)

    Opacka-Juffry, Jolanta; Pinnell, Thomas; Patel, Nisha; Bevan, Melissa; Meintel, Meghan; Davidson, Colin

    2014-10-01

    Mephedrone, an erstwhile "legal high", and some non-abused cathinones (ethcathinone, diethylpropion and bupropion) were tested for stimulant effects in vitro, through assessing their abilities to increase basal and electrically evoked dopamine efflux in rat accumbens brain slices, and compared with cocaine and amphetamine. We also tested mephedrone against cocaine in a dopamine transporter binding study. Dopamine efflux was electrically evoked and recorded using voltammetry in the rat accumbens core. We constructed concentration response curves for these cathinones for effects on basal dopamine levels; peak efflux after local electrical stimulation and the time-constant of the dopamine decay phase, an index of dopamine reuptake. We also examined competition between mephedrone or cocaine and [(125)I]RTI121 at the dopamine transporter. Mephedrone was less potent than cocaine at displacing [(125)I]RTI121. Mephedrone and amphetamine increased basal levels of dopamine in the absence of electrical stimulation. Cocaine, bupropion, diethylpropion and ethcathinone all increased the peak dopamine efflux after electrical stimulation and slowed dopamine reuptake. Cocaine was more potent than bupropion and ethcathinone, while diethylpropion was least potent. Notably, cocaine had the fastest onset of action. These data suggest that, with respect to dopamine efflux, mephedrone is more similar to amphetamine than cocaine. These findings also show that cocaine was more potent than bupropion and ethcathinone while diethylpropion was least potent. Mephedrone's binding to the dopamine transporter is consistent with stimulant effects but its potency was lower than that of cocaine. These findings confirm and further characterize stimulant properties of mephedrone and other cathinones in adolescent rat brain.

  18. Two-photon microscope for multisite microphotolysis of caged neurotransmitters in acute brain slices

    Science.gov (United States)

    Losavio, Bradley E.; Iyer, Vijay; Saggau, Peter

    2009-11-01

    We developed a two-photon microscope optimized for physiologically manipulating single neurons through their postsynaptic receptors. The optical layout fulfills the stringent design criteria required for high-speed, high-resolution imaging in scattering brain tissue with minimal photodamage. We detail the practical compensation of spectral and temporal dispersion inherent in fast laser beam scanning with acousto-optic deflectors, as well as a set of biological protocols for visualizing nearly diffraction-limited structures and delivering physiological synaptic stimuli. The microscope clearly resolves dendritic spines and evokes electrophysiological transients in single neurons that are similar to endogenous responses. This system enables the study of multisynaptic integration and will assist our understanding of single neuron function and dendritic computation.

  19. A Slice of the Suicidal Brain: What Have Postmortem Molecular Studies Taught Us?

    Science.gov (United States)

    Almeida, Daniel; Turecki, Gustavo

    2016-11-01

    Suicide ranks amongst the leading causes of death worldwide. Contemporary models of suicide risk posit that suicide results from the interaction of distal and proximal factors, including neurobiological, psychological/clinical, and social factors. While a wealth of neurobiological studies aimed at identifying biological processes associated with suicidal behaviour have been conducted over the last decades, the more recent development of arrays and high-throughput sequencing methods have led to an increased capacity and interest in the study of genomic factors. Postmortem studies are a unique tool to directly investigate genomic processes that may be dysregulated in the suicidal brain. In this review, we discuss postmortem literature investigating functional genomic studies of suicide, particularly focusing on epigenetic mechanisms. PMID:27671915

  20. Eye-position recording during brain MRI examination to identify and characterize steps of glioma diagnosis

    Science.gov (United States)

    Cavaro-Ménard, Christine; Tanguy, Jean-Yves; Le Callet, Patrick

    2010-02-01

    MRI is an essential tool for brain glioma diagnosis thanks to its ability to produce images in any layout plan and to its numerous sequences adapted to both anatomic and functional imaging. In this paper, we investigate the use of an eyetracking system to explore relationships between visual scanning patterns and the glioma diagnostic process during brain MRI analysis. We divide the analyzed screen into Areas of Interest (AOIs), each AOI corresponding to one sequence. Analyzing temporal organization of fixation location intra AOI and inter AOI splits the diagnostic process into different steps. The analysis of saccadic amplitudes reveals clear delineation of three sequential steps. During the first step (characterized by large saccades), a radiologist performs a short review on all sequences and on the patient report. In the second step (characterized by short saccades), a radiologist sequentially and systematically scans all the slices of each sequence. The fixation duration in one AOI depends on the number of slices, on the lesion subtlety and on the lesion contrast in the sequence to be analyzed. In order to improve the detection, localization and characterization of the glioma, the radiologist compares sequences during the third step (characterized by large saccades). Eye-position recording enables one to identify each elementary task implemented during diagnostic process of glioma detection and characterization on brain MRI. Total dwell time associated with one MRI sequence (one AOI) and contrast in primary lesion area enable one to estimate the amount and subtleties of diagnosis criteria provided by the sequence. From this information, one could establish some rules to optimize brain MRI compression (depending on the sequence to be compressed).

  1. Whole-brain CT perfusion and CT angiography assessment of Moyamoya disease before and after surgical revascularization: preliminary study with 256-slice CT.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available BACKGROUND/AIMS: The 256-slice CT enables the entire brain to be scanned in a single examination. We evaluated the application of 256-slice whole-brain CT perfusion (CTP in determining graft patency as well as investigating cerebral hemodynamic changes in Moyamoya disease before and after surgical revascularization. METHODS: Thirty-nine cases of Moyamoya disease were evaluated before and after surgical revascularization with 256-slice CT. Whole-brain perfusion images and dynamic 3D CT angiographic images generated from perfusion source data were obtained in all patients. Cerebral blood flow (CBF, cerebral blood volume (CBV, time to peak (TTP and mean transit time (MTT of one hemisphere in the region of middle cerebral artery (MCA distribution and contralateral mirroring areas were measured. Relative CTP values (rCBF, rCBV, rTTP, rMTT were also obtained. Differences in pre- and post- operation perfusion CT values were assessed with paired t test or matched-pairs signed-ranks test. RESULTS: Preoperative CBF, MTT and TTP of potential surgical side were significantly different from those of contralateral side (P<0.01 for all. All graft patencies were displayed using the 3D-CTA images. Postoperative CBF, rCBF and rCBV values of surgical side in the region of MCA were significantly higher than those before operation (P<0.01 for all. Postoperative MTT, TTP, rMTT and rTTP values of the surgical side in the region of MCA were significantly lower than those before operation (P<0.05 for all. CONCLUSION: The 256-slice whole-brain CTP can be used to evaluate cerebral hemodynamic changes in Moyamoya disease before and after surgery and the 3D-CTA is useful for assessing the abnormalities of intracranial arteries and graft patencies.

  2. A Unified Approach to Diffusion Direction Sensitive Slice Registration and 3-D DTI Reconstruction From Moving Fetal Brain Anatomy

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Seshamani, Sharmishtaa; Kroenke, Christopher;

    2014-01-01

    (AUDiSSAR) that explicitly formulates a process for diffusion direction sensitive DW-slice-to-DTI-volume alignment. This also incorporates image resolution modeling to iteratively deconvolve the effects of the imaging point spread function using the multiple views provided by thick slices acquired...

  3. Cranial CT with 64-, 16-, 4- and single-slice CT systems-comparison of image quality and posterior fossa artifacts in routine brain imaging with standard protocols

    Energy Technology Data Exchange (ETDEWEB)

    Ertl-Wagner, Birgit; Eftimov, Lara; Becker, Christoph; Reiser, Maximilian [University of Munich, Grosshadern (Germany). Institute of Clinical Radiology; Blume, Jeffrey; Cormack, Jean [Brown University, Center for Statistical Sciences, Providence, RI (United States); Bruening, Roland; Brueckmann, Hartmut [University of Munich, Grosshadern (Germany). Department of Neuroradiology

    2008-08-15

    Posterior fossa artifacts constitute a characteristic limitation of cranial CT. To identify practical benefits and drawbacks of newer CT systems with reduced collimation in routine cranial imaging, we aimed to investigate image quality, posterior fossa artifacts and parenchymal delineation in non-enhanced CT (NECT) with 1-, 4-, 16- and 64-slice scanners using standard scan protocols. We prospectively enrolled 25 consecutive patients undergoing NECT on a 64-slice CT. Three groups with 25 patients having undergone NECT on 1-, 4- and 16-slice CT machines were matched regarding age and sex. Standard routine CT parameters were used on each CT system with helical acquisition in the posterior fossa; the parameters varied regarding collimation and radiation dose. Three blinded readers independently assessed the cases regarding image quality, infra- and supratentorial artifacts and delineation of brain parenchymal structures on a five-point ordinal scale. Reading orders were randomized. A proportional odds model that accounted for the correlated nature of the data was fit using generalized estimating equations. Posterior fossa artifacts were significantly reduced, and the delineation of infratentorial brain structures was significantly improved with the thinner collimation used for the newer CT systems (p<0.001). No significant differences were observed for midbrain structures (p>0.5). The thinner collimation available on modern CT systems leads to reduced posterior fossa artifacts and to a better delineation of brain parenchyma in the posterior fossa. (orig.)

  4. Microfluidics and multielectrode array-compatible organotypic slice culture method.

    Science.gov (United States)

    Berdichevsky, Yevgeny; Sabolek, Helen; Levine, John B; Staley, Kevin J; Yarmush, Martin L

    2009-03-30

    Organotypic brain slice cultures are used for a variety of molecular, electrophysiological, and imaging studies. However, the existing culture methods are difficult or expensive to apply in studies requiring long-term recordings with multielectrode arrays (MEAs). In this work, a novel method to maintain organotypic cultures of rodent hippocampus for several weeks on standard MEAs in an unmodified tissue culture incubator is described. Polydimethylsiloxane (Sylgard) mini-wells were used to stabilize organotypic cultures on glass and MEA surfaces. Hippocampus slices were successfully maintained within PDMS mini-wells for multiple weeks, with preserved pyramidal layer organization, connectivity, and activity. MEAs were used to record the development of spontaneous activity in an organotypic cultures for 4 weeks. This method is compatible with integration of microchannels into the culture substrate. Microchannels were incorporated into the mini-wells and applied to the guidance of axons originating within the slice, paving the way for studies of axonal sprouting using organotypic slices.

  5. Comparison of iterative model, hybrid iterative, and filtered back projection reconstruction techniques in low-dose brain CT: impact of thin-slice imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakaura, Takeshi; Iyama, Yuji; Kidoh, Masafumi; Yokoyama, Koichi [Amakusa Medical Center, Diagnostic Radiology, Amakusa, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Oda, Seitaro; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Tokuyasu, Shinichi [Philips Electronics, Kumamoto (Japan); Harada, Kazunori [Amakusa Medical Center, Department of Surgery, Kumamoto (Japan)

    2016-03-15

    The purpose of this study was to evaluate the utility of iterative model reconstruction (IMR) in brain CT especially with thin-slice images. This prospective study received institutional review board approval, and prior informed consent to participate was obtained from all patients. We enrolled 34 patients who underwent brain CT and reconstructed axial images with filtered back projection (FBP), hybrid iterative reconstruction (HIR) and IMR with 1 and 5 mm slice thicknesses. The CT number, image noise, contrast, and contrast noise ratio (CNR) between the thalamus and internal capsule, and the rate of increase of image noise in 1 and 5 mm thickness images between the reconstruction methods, were assessed. Two independent radiologists assessed image contrast, image noise, image sharpness, and overall image quality on a 4-point scale. The CNRs in 1 and 5 mm slice thickness were significantly higher with IMR (1.2 ± 0.6 and 2.2 ± 0.8, respectively) than with FBP (0.4 ± 0.3 and 1.0 ± 0.4, respectively) and HIR (0.5 ± 0.3 and 1.2 ± 0.4, respectively) (p < 0.01). The mean rate of increasing noise from 5 to 1 mm thickness images was significantly lower with IMR (1.7 ± 0.3) than with FBP (2.3 ± 0.3) and HIR (2.3 ± 0.4) (p < 0.01). There were no significant differences in qualitative analysis of unfamiliar image texture between the reconstruction techniques. IMR offers significant noise reduction and higher contrast and CNR in brain CT, especially for thin-slice images, when compared to FBP and HIR. (orig.)

  6. Comparison of iterative model, hybrid iterative, and filtered back projection reconstruction techniques in low-dose brain CT: impact of thin-slice imaging

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the utility of iterative model reconstruction (IMR) in brain CT especially with thin-slice images. This prospective study received institutional review board approval, and prior informed consent to participate was obtained from all patients. We enrolled 34 patients who underwent brain CT and reconstructed axial images with filtered back projection (FBP), hybrid iterative reconstruction (HIR) and IMR with 1 and 5 mm slice thicknesses. The CT number, image noise, contrast, and contrast noise ratio (CNR) between the thalamus and internal capsule, and the rate of increase of image noise in 1 and 5 mm thickness images between the reconstruction methods, were assessed. Two independent radiologists assessed image contrast, image noise, image sharpness, and overall image quality on a 4-point scale. The CNRs in 1 and 5 mm slice thickness were significantly higher with IMR (1.2 ± 0.6 and 2.2 ± 0.8, respectively) than with FBP (0.4 ± 0.3 and 1.0 ± 0.4, respectively) and HIR (0.5 ± 0.3 and 1.2 ± 0.4, respectively) (p < 0.01). The mean rate of increasing noise from 5 to 1 mm thickness images was significantly lower with IMR (1.7 ± 0.3) than with FBP (2.3 ± 0.3) and HIR (2.3 ± 0.4) (p < 0.01). There were no significant differences in qualitative analysis of unfamiliar image texture between the reconstruction techniques. IMR offers significant noise reduction and higher contrast and CNR in brain CT, especially for thin-slice images, when compared to FBP and HIR. (orig.)

  7. Interfacing with the brain using organic electronics (Presentation Recording)

    Science.gov (United States)

    Malliaras, George G.

    2015-10-01

    Implantable electrodes are being used for diagnostic purposes, for brain-machine interfaces, and for delivering electrical stimulation to alleviate the symptoms of diseases such as Parkinson's. The field of organic electronics made available devices with a unique combination of attractive properties, including mixed ionic/electronic conduction, mechanical flexibility, enhanced biocompatibility, and capability for drug delivery. I will present examples of organic electrodes, transistors and other devices for recording and stimulation of brain activity and discuss how they can improve our understanding of brain physiology and pathology, and how they can be used to deliver new therapies.

  8. A New Look at the Paleocene/Eocene Thermal Maximum in New Jersey: Dicing and Slicing the Stratigraphic Record

    Science.gov (United States)

    Wright, J. D.; Miller, K. G.; Aubry, M.; Browning, J. V.; Harris, A. D.; Godfrey, L. V.; Babila, T.; Cramer, B. S.

    2011-12-01

    We correlated eight onshore sites (Clayton, Wilson Lake, Sea Girt, Ancora, Millville, Double Trouble, Island Beach, and Bass River) in the New Jersey coastal plain spanning the Paleocene/Eocene Thermal Maximum (PETM), using carbon isotopic stratigraphy constrained by nannofossil biostratigraphy. Coastal plain records are correlated to astronomical and He-3 chronologies in deep sea sites, which suggests high coastal plain sedimentation rates (5 to >10 cm/kyr). We recognize 6 PETM intervals from older to younger: 1) a precursor δ13C increase at Wilson Lake and Ancora that occurs within the silts of the Vincentown Formation; 2) the Carbon Isotopic Excursion (CIE) decrease of 5-7 per mil which occurs in at least 1 sharp step (Marlboro Clay Member; 3) a longer interval (~20-30 kyr) of decreasing values; 3) a "boxcar" interval of universally low and constant δ13C values that lasted 30-40 kyr; 4) an exponential interval of recovery to δ13C values that were 1-2% lower than pre-CIE values over 40 kyr (He-3) to 65 kyr (astronomical) that marks the top of the Marlboro Clay; and 5) a distinct sequence E0 of the Vincentown Formation whose base appears to be a regional if not global sea level lowering. There is also likely a sequence boundary at or immediately below the precursor δ13C, though the significance of this is unclear. The basal E0 sequence boundary completely truncates the Marlboro Clay (CIE through recovery interval) at Island Beach and Double Trouble, truncates the recovery interval at Sea Girt, Ancora, and Bass River, and partially truncates the recovery at Wilson Lake, which dates the sea-level fall as ~100 kyr younger than the CIE. The CIE to recovery interval thus occurs within one sequence named Eα, and is likely bracketed by regional if not global sea-level falls. The dicing and slicing of the PETM interval is due to erosion associated with the E0 sequence boundary and emphasizes that integrated isotope stratigraphy is necessary to parse out complex

  9. Dynamic changes in glucose metabolism of living rat brain slices induced by hypoxia and neurotoxic chemical-loading revealed by positron autoradiography

    International Nuclear Information System (INIS)

    Fresh rat brain slices were incubated with 2-deoxy-2-[18F]-fluoro-D-glucose ([18F]FDG) in oxygenated Krebs-Ringer solution at 36 degree C, and serial two-dimensional time-resolved images of [18F]FDG uptake were obtained from these specimens on imaging plates. The fractional rate constant (= k3*) of [18F]FDG proportional to the cerebral glucose metabolic rate (CMRglc) was evaluated by applying the Gjedde-Patlak graphical method to the image data. With hypoxia loading (oxygen deprivation) or glucose metabolism inhibitors acting on oxidative phosphorylation, the k3* value increased dramatically suggesting enhanced glycolysis. After relieving hypoxia ≤10-min, the k3* value returned to the pre-loading level. In contrast, with ≥20-min hypoxia only partial or no recovery was observed, indicating that irreversible neuronal damage had been induced. However, after loading with tetrodotoxin (TTX), the k3* value also decreased but returned to the pre-loading level even after 70-min TTX-loading, reflecting a transient inhibition of neuronal activity. This technique provides a new means of quantifying dynamic changes in the regional CMRglc in living brain slices in response to various interventions such as hypoxia and neurotoxic chemical-loading as well as determining the viability and prognosis of brain tissues. (author)

  10. Initial experience of whole-brain perfusion imaging performed with 256-slice CT%256层螺旋CT全脑灌注成像的初步研究

    Institute of Scientific and Technical Information of China (English)

    唐健; 姜建威; 常军; 侯海燕; 姜旭栋; 堵红群

    2011-01-01

    目的:初步评价256层螺旋CT全脑灌注成像对正常脑血流动力学测定的可行性和价值.方法:从拟诊缺血性脑病行头颅平扫、头颅灌注成像及头颈部血管成像的114例患者中选取检查结果正常者35例,记录头颅灌注成像的辐射剂量,由两名高年资神经放射科医生分别对灌注图像进行分析,选择基底节层面和侧脑室体部层面的两侧大脑中动脉供血区的颞叶皮质进行测定,通过手动勾画选定层面的感兴趣区,CT灌注软件自动生成感兴趣区的脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTr)、达峰时间(TTP)值,测得的灌注参数均值进行单因素方差分析.结果:35例正常人的辐射剂量为(2.307±0.008)mSv.2名分析者所测得侧脑室体部层面和基底节层面的颞叶灰质的CBF、CBV、MTr、TTP值之间无明显统计学差异(P>0.05).2名分析者测得的两个层面的颞叶灰质的CBV、CBF值之间均有统计学差异(P<0.05).结论:256层螺旋CT全脑灌注成像辐射剂量低,脑灌注参数稳定,能够更真实的反应全脑血流动力学改变.%Objective;To preliminarily evaluate the feasibility and potential values of whole-brain perfusion imaging performed with 256-slice CT to assess normal adult cerebral hemodynamics. Methods; Thirty-five normal results were selected from one hundred and fourteen patients who underwent brain CT unenhanced scan.CT perfusion imaging and CT angiography in head and neck for suspicion of ischemic cerebrovascular disease. The radiation dosage of CT perfusion imaging was recorded. Two senior neuroradiologic doctors independently analyzed the CT perfusion maps. Region of interest (ROI) was placed on bilateral temporal gray matter of two slices (the basal ganglia slice and body of lateral cerebral ventricle slice) supplied by middle cerebral artery,and the cerebral blood flow(CBF),cerebral blood volume(CBV),mean transiting time(MTT), and time to peak(TTP) values of ROI

  11. Architectural slicing

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2013-01-01

    a system and a slicing criterion, architectural slicing produces an architectural prototype that contain the elements in the architecture that are dependent on the ele- ments in the slicing criterion. Furthermore, we present an initial design and implementation of an architectural slicer for Java.......Architectural prototyping is a widely used practice, con- cerned with taking architectural decisions through experiments with light- weight implementations. However, many architectural decisions are only taken when systems are already (partially) implemented. This is prob- lematic in the context...... of architectural prototyping since experiments with full systems are complex and expensive and thus architectural learn- ing is hindered. In this paper, we propose a novel technique for harvest- ing architectural prototypes from existing systems, \\architectural slic- ing", based on dynamic program slicing. Given...

  12. A brain slice culture model for studies of endogenous and exogenous precursor cell migration in the rostral migratory stream

    DEFF Research Database (Denmark)

    Tanvig, Mette; Blaabjerg, Morten; Andersen, Rikke K;

    2009-01-01

    a slice culture preparation of the rat forebrain including en suite the rostral part of the lateral ventricle, the RMS and the OB. The preparation was validated with regard to endogenous cell proliferation and migration by tracking bromodeoxyuridine (BrdU)-labelled cells in newly established and 3 and 6...

  13. Reproducibility of perfusion CT derived CBV and rCBV measurements with different slice thickness in patients with brain neoplasms%脑瘤灌注CT不同层厚CBV与rCBV测量的可重复性研究

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: To assess inter-and intraobserver reproducibility for measuring perfusion CT derived cerebral blood volume(CBV)and relative cerebral blood volume(rCBV)with different slice thickness in patients with brain neoplasms.Methods: Three independent observers who were blinded to the histopathologic diagnosis performed perfusion derived CBV and rCBV measurements with 5 mm and 10 mm slice thickness in 52 patients with various cerebral neoplasms.The results of the measurements with different slice thickness were compared.Calculation of coefficient of variation(CV), and relative paired difference of the measurements were used to determine the levels of inter-and intraobserver reproducibility.Results: The differences of CBV and rCBV measurements between different slice thickness groups were statistically significant(P<0.05)respectively in observer 2, and were not significant in the other two observers(P>0.05).For the same slice thickness, both the difference of CBV and rCBV measurements among the three observers were not statistically significant.Interobserver CV and relative paired difference of the measurements with 10 mm slice thickness group were slightly lower than those of 5 mm slice thickness group.Interobserver CV and relative paired difference of CBV group were slightly lower than those of rCBV group.The intraobserver differences of CBV and rCBV in 10 mm slice thickness group were statistically significant for observer 2 respectively.No other intraobserver differences of measurements were statistically significant.CV and relative paired difference of intraobserver CBV and rCBV measurements for observer 2 were significantly higher than for the other two observers.Conclusion: High reproducibility of CBV and rCBV measurements was acquired with the two different slice thickness.Suitable training may be helpful to maintain a high level of consistency for measurements.

  14. Trafficking of astrocytic vesicles in hippocampal slices

    International Nuclear Information System (INIS)

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  15. Trafficking of astrocytic vesicles in hippocampal slices

    Energy Technology Data Exchange (ETDEWEB)

    Potokar, Maja; Kreft, Marko [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia); Lee, So-Young; Takano, Hajime; Haydon, Philip G. [Department of Neuroscience, Room 215, Stemmler Hall, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104 (United States); Zorec, Robert, E-mail: Robert.Zorec@mf.uni-lj.si [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia)

    2009-12-25

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  16. Using Multiple Whole-Cell Recordings to Study Spike-Timing-Dependent Plasticity in Acute Neocortical Slices.

    Science.gov (United States)

    Lalanne, Txomin; Abrahamsson, Therese; Sjöström, P Jesper

    2016-01-01

    This protocol provides a method for quadruple whole-cell recording to study synaptic plasticity of neocortical connections, with a special focus on spike-timing-dependent plasticity (STDP). It also describes how to morphologically identify recorded cells from two-photon laser-scanning microscopy (2PLSM) stacks. PMID:27250948

  17. Influence of location of a fluorescent zinc probe in brain slices on its response to synaptic activation.

    Science.gov (United States)

    Kay, Alan R; Tóth, Katalin

    2006-03-01

    The precise role of the high concentration of ionic zinc found in the synaptic vesicles of certain glutamatergic terminals is unknown. Fluorescent probes with their ability to detect ions at low concentrations provide a powerful approach to monitoring cellular Zn2+ levels. In the last few years, a number of fluorescent probes (indicators) have been synthesized that can be used to visualize Zn2+ in live cells. The interpretation of data gathered using such probes depends crucially on the location of the probe. Using acutely prepared hippocampal slices, we provide evidence that the Zn2+ probes, ZnAF-2 and ZP4, are membrane permeant and are able to pass into synaptic vesicles. In addition, we show that changes in fluorescence of the Zn2+ probes can be used to monitor presynaptic activity; however, these changes are inconsistent with Zn2+ release.

  18. Noise-free magnetoencephalography recordings of brain function

    Energy Technology Data Exchange (ETDEWEB)

    Volegov, P; Matlachov, A; Mosher, J; Espy, M A; Kraus, R H Jr. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-05-21

    Perhaps the greatest impediment to acquiring high-quality magnetoencephalography (MEG) recordings is the ubiquitous ambient magnetic field noise. We have designed and built a whole-head MEG system using a helmet-like superconducting imaging surface (SIS) surrounding the array of superconducting quantum interference device (SQUID) magnetometers used to measure the MEG signal. We previously demonstrated that the SIS passively shields the SQUID array from ambient magnetic field noise, independent of frequency, by 25-60 dB depending on sensor location. SQUID 'reference sensors' located on the outside of the SIS helmet measure ambient magnetic fields in very close proximity to the MEG magnetometers while being nearly perfectly shielded from all sources in the brain. The fact that the reference sensors measure no brain signal yet are located in close proximity to the MEG sensors enables very accurate estimation and subtraction of the ambient field noise contribution to the MEG sensors using an adaptive algorithm. We have demonstrated total ambient noise reduction factors in excess of 10{sup 6} (>120 dB). The residual noise for most MEG SQUID channels is at or near the intrinsic SQUID noise floor, typically 2-3 f T Hz{sup -1/2}. We are recording MEG signals with greater signal-to-noise than equivalent EEG measurements.

  19. Noise-free magnetoencephalography recordings of brain function

    Science.gov (United States)

    Volegov, P.; Matlachov, A.; Mosher, J.; Espy, M. A.; Kraus, R. H., Jr.

    2004-05-01

    Perhaps the greatest impediment to acquiring high-quality magnetoencephalography (MEG) recordings is the ubiquitous ambient magnetic field noise. We have designed and built a whole-head MEG system using a helmet-like superconducting imaging surface (SIS) surrounding the array of superconducting quantum interference device (SQUID) magnetometers used to measure the MEG signal. We previously demonstrated that the SIS passively shields the SQUID array from ambient magnetic field noise, independent of frequency, by 25-60 dB depending on sensor location. SQUID 'reference sensors' located on the outside of the SIS helmet measure ambient magnetic fields in very close proximity to the MEG magnetometers while being nearly perfectly shielded from all sources in the brain. The fact that the reference sensors measure no brain signal yet are located in close proximity to the MEG sensors enables very accurate estimation and subtraction of the ambient field noise contribution to the MEG sensors using an adaptive algorithm. We have demonstrated total ambient noise reduction factors in excess of 106 (>120 dB). The residual noise for most MEG SQUID channels is at or near the intrinsic SQUID noise floor, typically 2-3 f T Hz-1/2. We are recording MEG signals with greater signal-to-noise than equivalent EEG measurements.

  20. Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane;

    The brain is the center of the nervous system, where serious neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s are products of functional loss in the neural cells (1). Typical techniques used to investigate these diseases lack precise control of the cellular surroundings...

  1. The inflammatory molecules IL-1β and HMGB1 can rapidly enhance focal seizure generation in a brain slice model of temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Angela eChiavegato

    2014-06-01

    Full Text Available Epilepsy is a neurological disorder characterized by a hyperexcitable brain tissue and unpredictable seizures, i.e., aberrant firing discharges in large neuronal populations. It is well established that proinflammatory cytokines, in addition to their canonical involvement in the immune response, have a crucial role in the mechanism of seizure generation. The purpose of the present study was to investigate the role of interleukin-1β (IL-1β and high mobility group B1 (HMGB1 in the generation of seizure-like discharges using two models of focal epilepsy in a rat entorhinal cortex slice preparation. Seizure like-discharges were evoked by either slice perfusion with low Mg2+ and picrotoxin or with a double NMDA local stimulation in the presence of the proconvulsant 4-amino-pyridine. The effects of IL-1β or HMGB1 were evaluated by monitoring seizure discharge generation through laser scanning microscope imaging of Ca2+ signals from neurons and astrocytes. In the picrotoxin model, we revealed that both cytokines increased the mean frequency of spontaneous ictal-like discharges, whereas only IL-1β reduced the latency and prolonged the duration of the first ictal-like event. In the second model, a single NMDA pulse, per se ineffective, became successful when it was performed after IL-β or HMGB1 local applications. These findings demonstrate that both IL-1β and HMGB1 can rapidly lower focal ictal event threshold and strengthen the possibility that targeting these inflammatory pathways may represent an effective therapeutic strategy to prevent seizures.

  2. Neuroprotective effects of stearic acid against toxicity of oxygen/glucose deprivation or glutamate on rat cortical or hippocampal slices

    Institute of Scientific and Technical Information of China (English)

    Ze-jian WANG; Guang-mei LI; Wen-lu TANG; Ming YIN

    2006-01-01

    Aim: To observe the effects of stearic acid, a long-chain saturated fatty acid consisting of 18 carbon atoms, on brain (cortical or hippocampal) slices insulted by oxygen-glucose deprivation (OGD), glutamate or sodium azide (NaN3) in vitro.Methods: The activities of hippocampal slices were monitored by population spikes recorded in the CA1 region. In vitro injury models of brain slice were induced by 10 min of OGD, 1 mmol/L glutamate or 10 mmol/L NaN3. After 30 min of preincubation with stearic acid (3-30 μmol/L), brain slices (cortical or hippocampal)were subjected to OGD, glutamate or NaN3, and the tissue activities were evaluated by using the 2,3,5-triphenyltetrazolium chloride method. MK886 [5 mmol/L;a noncompetitive inhibitor of proliferator-activated receptor (PPAR-α)] or BADGE (bisphenol A diglycidyl ether; 100 μmol/L; an antagonist of PPAR-γ) were tested for their effects on the neuroprotection afforded by stearic acid. Results: Viability of brain slices was not changed significantly after direct incubation with stearic acid. OGD, glutamate and NaN3 injury significantly decreased the viability of brain slices. Stearic acid (3-30 μmol/L) dose-dependently protected brain slices from OGD and glutamate injury but not from NaN3 injury, and its neuroprotective effect was completely abolished by BADGE. Conclusion: Stearic acid can protect brain slices (cortical or hippocampal) against injury induced by OGD or glutamate.Its neuroprotective effect may be mainly mediated by the activation of PPAR-γ.

  3. Evaluation of 2D multiband EPI imaging for high-resolution, whole-brain, task-based fMRI studies at 3T: Sensitivity and slice leakage artifacts.

    Science.gov (United States)

    Todd, Nick; Moeller, Steen; Auerbach, Edward J; Yacoub, Essa; Flandin, Guillaume; Weiskopf, Nikolaus

    2016-01-01

    Functional magnetic resonance imaging (fMRI) studies that require high-resolution whole-brain coverage have long scan times that are primarily driven by the large number of thin slices acquired. Two-dimensional multiband echo-planar imaging (EPI) sequences accelerate the data acquisition along the slice direction and therefore represent an attractive approach to such studies by improving the temporal resolution without sacrificing spatial resolution. In this work, a 2D multiband EPI sequence was optimized for 1.5mm isotropic whole-brain acquisitions at 3T with 10 healthy volunteers imaged while performing simultaneous visual and motor tasks. The performance of the sequence was evaluated in terms of BOLD sensitivity and false-positive activation at multiband (MB) factors of 1, 2, 4, and 6, combined with in-plane GRAPPA acceleration of 2× (GRAPPA 2), and the two reconstruction approaches of Slice-GRAPPA and Split Slice-GRAPPA. Sensitivity results demonstrate significant gains in temporal signal-to-noise ratio (tSNR) and t-score statistics for MB 2, 4, and 6 compared to MB 1. The MB factor for optimal sensitivity varied depending on anatomical location and reconstruction method. When using Slice-GRAPPA reconstruction, evidence of false-positive activation due to signal leakage between simultaneously excited slices was seen in one instance, 35 instances, and 70 instances over the ten volunteers for the respective accelerations of MB 2×GRAPPA 2, MB 4×GRAPPA 2, and MB 6×GRAPPA 2. The use of Split Slice-GRAPPA reconstruction suppressed the prevalence of false positives significantly, to 1 instance, 5 instances, and 5 instances for the same respective acceleration factors. Imaging protocols using an acceleration factor of MB 2×GRAPPA 2 can be confidently used for high-resolution whole-brain imaging to improve BOLD sensitivity with very low probability for false-positive activation due to slice leakage. Imaging protocols using higher acceleration factors (MB 3 or MB 4

  4. Quantitative evaluation of benign meningioma and hemangiopericytoma with peritumoral brain edema by 64-slice CT perfusion imaging

    Institute of Scientific and Technical Information of China (English)

    REN Guang; CHEN Shuang; WANG Yin; ZHU Rui-jiang; GENG Dao-ying; FENG Xiao-yuan

    2010-01-01

    Background Hemangiopericytomas (HPCs) have a relentless tendency for local recurrence and metastases,differentiating between benign meningiomas and HPCs before surgery is important for both treatment planning and the prognosis appraisal.The purpose of this study was to evaluate the correlations between CT perfusion parameters and microvessel density (MVD) in extra-axial tumors and the possible role of CT perfusion imaging in preoperatively differentiating benign meningiomas and HPCs.Methods Seventeen patients with benign meningiomas and peritumoral edema, 12 patients with HPCs and peritumoral edema underwent 64-slice CT perfusion imaging pre-operation.Perfusion was calculated using the Patlak method.The quantitative parameters, include cerebral blood volume (CBV), permeability surface (PS) of parenchyma, peritumoral edema among benign meningiomas and HPCs were compared respectively.CBV and PS in parenchyma, peritumoral edema of benign meningiomas and HPCs were also compared to that of the contrallateral normal white matter respectively.The correlations between CBV, PS of tumoral parenchyma and MVD were examined.Results The value of CBV and PS in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05), while the values of CBV and PS in peritumoral edema of benign meningiomas and HPCs were not significantly different (P >0.05).MVD in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05).There were positive correlations between CBV and MVD (r=0.648, P<0.05), PS and MVD (r=0.541, P<0.05) respectively.Furthermore, the value of CBV and PS in parenchyma of benign meningiomas and HPCs were significantly higher than that of contrallateral normal white matter (P<0.05), the value of CBV in peritumoral edema of benign meningiomas and HPCs were significantly lower than that of contrallateral normal white matter (P<0.05), while the value of PS in peritumoral edema of benign meningiomas and HPCs were not

  5. 31P-saturation-transfer nuclear-magnetic-resonance measurements of phosphocreatine turnover in guinea-pig brain slices.

    Science.gov (United States)

    Morris, P G; Feeney, J; Cox, D W; Bachelard, H S

    1985-05-01

    The technique of 31P saturation-transfer n.m.r. was used to determine the forward and the reverse rate constants of creatine phosphotransferase in superfused guinea-pig cerebral tissues in vitro. The calculated forward rate constant of 0.22 +/- 0.03s-1 compared well with a previously reported value for rat brain in vivo [Shoubridge, Briggs & Radda (1982) FEBS Lett. 140, 288-292]. The reverse rate constant was found to be 0.55 +/- 0.10s-1. 3. By using concentrations of ATP and phosphocreatine estimated previously for this superfused preparation [Cox, Morris, Feeney & Bachelard (1983) Biochem. J. 212, 365-370], forward and reverse flux rates were calculated to be 0.68 and 0.72 mumol X s-1 X g-1 respectively. The concordance of forward and reverse fluxes contrasts with the situation observed in vitro in other tissues, and suggests that the creatine phosphotransferase reaction is at equilibrium under the conditions used here. 4. Lowering the concentration of glucose in the superfusing medium from 10mM to 0.5mM had no significant effect on phosphocreatine concentration or on the forward (ATP-generating) flux through creatine phosphotransferase. The results indicate that a normal phosphocreatine content in the presence of lowered glucose availability is reflected by an unchanged turnover rate.

  6. Central Administration of Lipopolysaccharide Induces Depressive-like Behavior in Vivo and Activates Brain Indoleamine 2,3 Dioxygenase In Murine Organotypic Hippocampal Slice Cultures

    Directory of Open Access Journals (Sweden)

    Kavelaars Annemieke

    2010-08-01

    Full Text Available Abstract Background Transient stimulation of the innate immune system by an intraperitoneal injection of lipopolysaccharide (LPS activates peripheral and central expression of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO which mediates depressive-like behavior. It is unknown whether direct activation of the brain with LPS is sufficient to activate IDO and induce depressive-like behavior. Methods Sickness and depressive-like behavior in C57BL/6J mice were assessed by social exploration and the forced swim test, respectively. Expression of cytokines and IDO mRNA was measured by real-time RT-PCR and cytokine protein was measured by enzyme-linked immunosorbent assays (ELISAs. Enzymatic activity of IDO was estimated as the amount of kynurenine produced from tryptophan as determined by high pressure liquid chromatography (HPLC with electrochemical detection. Results Intracerebroventricular (i.c.v. administration of LPS (100 ng increased steady-state transcripts of TNFα, IL-6 and the inducible isoform of nitric oxide synthase (iNOS in the hippocampus in the absence of any change in IFNγ mRNA. LPS also increased IDO expression and induced depressive-like behavior, as measured by increased duration of immobility in the forced swim test. The regulation of IDO expression was investigated using in situ organotypic hippocampal slice cultures (OHSCs derived from brains of newborn C57BL/6J mice. In accordance with the in vivo data, addition of LPS (10 ng/ml to the medium of OHSCs induced steady-state expression of mRNA transcripts for IDO that peaked at 6 h and translated into increased IDO enzymatic activity within 8 h post-LPS. This activation of IDO by direct application of LPS was preceded by synthesis and secretion of TNFα and IL-6 protein and activation of iNOS while IFNγ expression was undetectable. Conclusion These data establish that activation of the innate immune system in the brain is sufficient to activate IDO and induce

  7. Progress in research of long-term potentiation on brain slice%在脑片水平上突触可塑性长时程增强的研究进展

    Institute of Scientific and Technical Information of China (English)

    郑小波; 田心; 宋毅军

    2008-01-01

    长时程增强(LTP)是突触效能的重要表现形式,是研究学习与记忆突触机制的客观指标.近年来随着脑片技术的发展,很多关于LTP的实验研究都在脑片水平上进行.介绍了海马脑片CA1区LTP的调节表达机制的研究,海马脑片上诱导产生的LTP的特征和脑片条件的关系,多巴胺转运蛋白阻断剂通过活化D3多巴胺受体增强海马脑片CA1区LTP,以及激活大鼠海马脑片CA1区突触β-肾上腺素能受体增强联合LTP的研究,综述了在脑片水平上研究LTP的诱导表达维持及调节等方面的研究动态和进展.%Long-term potentiation(LTP)is an important form of synaptic plasticity and an objective indicator to investigate learing and memory synaptic mechanisms.With the development of brain slice technology,more and more experiments associated with LTP are carried out on brain slices,which aim to investigate the mechanism in biology and the change in physiology or biochemistry are carried out on the brain slice.This paper gives an overview of recent advances in research of LTP with technology of brain sliceby suchexamples as follows:The regulated expression mechanisms of long-term potentiation at CA1 synapses,the characteristics of LTP induced in hippcampal slices and its relation with the slice-recovery conditions,the enhancement of the magnitude of early longterm potentiation at CA1 hippocampal synapse by the activation of dopamine receptor,and the enhancement of associative long-term potentiation by the activation of β-adrenergic receptors at CA1 synapses in rat hippocampol slices.

  8. A setup for administering TMS to medial and lateral cortical areas during whole-brain FMRI recording

    NARCIS (Netherlands)

    Weijer, A.D. de; Sommer, I.E.C.; Bakker, E.J.; Bloemendaal, M.; Bakker, C.J.; Klomp, D.W.J.; Bestmann, S.; Neggers, S.F.W.

    2014-01-01

    SUMMARY: Stimulating brain areas with transcranial magnetic stimulation (TMS) while concurrently and noninvasively recording brain activity changes through functional MRI enables a new range of investigations about causal interregional interactions in the human brain. However, standard head-coil arr

  9. Recording brain waves at the supermarket: what can we learn from a shopper's brain?

    Science.gov (United States)

    Sands, Stephen F; Sands, J Andrew

    2012-01-01

    cognitive and emotional activity and are complimentary. EEG is more sensitive to time-locked events (i.e., story lines), whereas fMRI is more sensitive to the brain regions involved. The application of neuroscience in BTL campaigns is significantly more difficult to achieve. Participants move unconstrained in a shopping environment while EEG and eye movements are monitored. In this scenario, fMRI is not possible. fMRI can be used with virtual store mock-ups, but it is expensive and seldom used. We have developed a technology that allows for the measurement of EEG in an unobtrusive manner. The intent is to record the brain waves of participants during their day-to-day shopping experience. A miniaturized video recorder, EEG amplifiers, and eye-tracking systems are used. Digital signal processing is employed to remove the substantial artifact generated by eye movements and motion. Eye fixations identify specific viewings of products and displays, and they are used for synchronizing the behavior with EEG response. The location of EEG sources is determined by the use of a source reconstruction software. PMID:22678838

  10. Thick Slice and Thin Slice Teaching Evaluations

    Science.gov (United States)

    Tom, Gail; Tong, Stephanie Tom; Hesse, Charles

    2010-01-01

    Student-based teaching evaluations are an integral component to institutions of higher education. Previous work on student-based teaching evaluations suggest that evaluations of instructors based upon "thin slice" 30-s video clips of them in the classroom correlate strongly with their end of the term "thick slice" student evaluations. This study's…

  11. NeuroGrid: recording action potentials from the surface of the brain

    OpenAIRE

    Khodagholy, Dion; Gelinas, Jennifer N.; Thesen, Thomas; Doyle, Werner; Devinsky, Orrin; Malliaras, George G.; Buzsáki, György

    2014-01-01

    Recording from neural networks at the resolution of action potentials is critical for understanding how information is processed in the brain. Here, we address this challenge by developing an organic material-based, ultra-conformable, biocompatible and scalable neural interface array (the ‘NeuroGrid’) that can record both LFP and action potentials from superficial cortical neurons without penetrating the brain surface. Spikes with features of interneurons and pyramidal cells were simultaneous...

  12. Material and physical model for evaluation of deep brain activity contribution to EEG recordings

    Science.gov (United States)

    Ye, Yan; Li, Xiaoping; Wu, Tiecheng; Li, Zhe; Xie, Wenwen

    2015-12-01

    Deep brain activity is conventionally recorded with surgical implantation of electrodes. During the neurosurgery, brain tissue damage and the consequent side effects to patients are inevitably incurred. In order to eliminate undesired risks, we propose that deep brain activity should be measured using the noninvasive scalp electroencephalography (EEG) technique. However, the deeper the neuronal activity is located, the noisier the corresponding scalp EEG signals are. Thus, the present study aims to evaluate whether deep brain activity could be observed from EEG recordings. In the experiment, a three-layer cylindrical head model was constructed to mimic a human head. A single dipole source (sine wave, 10 Hz, altering amplitudes) was embedded inside the model to simulate neuronal activity. When the dipole source was activated, surface potential was measured via electrodes attached on the top surface of the model and raw data were recorded for signal analysis. Results show that the dipole source activity positioned at 66 mm depth in the model, equivalent to the depth of deep brain structures, is clearly observed from surface potential recordings. Therefore, it is highly possible that deep brain activity could be observed from EEG recordings and deep brain activity could be measured using the noninvasive scalp EEG technique.

  13. A Simple Method for Measuring Organotypic Tissue Slice Culture Thickness

    OpenAIRE

    Guy, Yifat; Rupert, Amy; Sandberg, Mats; Weber, Stephen G.

    2011-01-01

    This paper presents a simple method to measure tissue slice thicknesses using an ohmmeter. The circuit described here is composed of a metal probe, an ohmmeter, a counter electrode, culture medium or physiological buffer, and tissue slice. The probe and the electrode are on opposite interfaces of an organotypic hippocampal slice culture. The circuit closes when the metal probe makes contact with the surface of the tissue slice. The probe position is recorded and compared to its position when ...

  14. A Valuable and Promising Method for Recording Brain Activity in Behaving Newborn Rodents

    OpenAIRE

    Blumberg, Mark S.; Sokoloff, Greta; Tiriac, Alexandre; Del Rio-Bermudez, Carlos

    2015-01-01

    Neurophysiological recording of brain activity has been critically important to the field of neuroscience, but has contributed little to the field of developmental psychobiology. The reasons for this can be traced largely to methodological difficulties associated with recording neural activity in behaving newborn rats and mice. Over the last decade, however, the evolution of methods for recording from head-fixed newborns has heralded a new era in developmental neurophysiology. Here, we review...

  15. Electrophysiological recording of the brain, visualization, prediction, and interconnectivity

    Science.gov (United States)

    Talakoub, Omid

    The human brain is a complex network of interconnected neurons. The aim of neuroscience and neuroengineering is to decode the neural activity, visualize it and try to better understand how neurons communicate with each other. This dissertation comprises four contributions to the area. These four topics are discussing how functional relationship between brain activity and movement can be found and whether common features found in different regions are correlated (phase-locked). First, the method of chirplet decomposition offers a new way to visualize the time-frequency content of non-stationary signals with higher resolution than previously possible. The use of Wigner-Ville distribution together with chirplet decomposition allows a clearer visualization in terms of both the temporal and frequency details with detail higher than previously achieved using other methods including Choi-Williams and spectrogram. Second, an improved method of averaging of neural signals over repeated trials is introduced whereby slight variations in the alignment of the neural signal over time is corrected through the use of nonlinear shifts. In earlier studies, time alignment has been performed using linear shift (e.g. alignment with movement onset), but this process alone is not sufficient when the signal timing changes differently over time. To overcome this issue, nonlinear transformations were found to remove any temporal variabilities in the way the task was performed. Third, a multilinear model is demonstrated showing how limb velocity in a reach task can be predicted from neuroelectrical activity. The model, after fitting, suggested that high frequency oscillations have sufficient information for both detection of movement onset and reconstruction of its movement. The use of a linear model reduces the overall computational requirements and simplifies the reconstruction of movement kinematics. Finally, a fourth method involving the measurement of coherence over time reveals how

  16. Slices and Ellipse Geometry

    OpenAIRE

    Dattoli, G.; Sabia, E.; Del Franco, M.; Petralia, A.

    2011-01-01

    We discuss the new problems emerging in charged beam transport for SASE FEL dynamics. The optimization of the magnetic transport system for future devices requires new concepts associated with the slice emittance and the slice phase space distribution. We study the problem of electron beam slice matching and guiding in transport devices for SASE FEL emission discussing matching criteria and how the associated design of the electron transport line may affect the FEL output performances. We ana...

  17. Ultrafast multi-slice spatiotemporally encoded MRI with slice-selective dimension segmented.

    Science.gov (United States)

    Zhang, Ting; Chen, Lin; Huang, Jianpan; Li, Jing; Cai, Shuhui; Cai, Congbo; Chen, Zhong

    2016-08-01

    As a recently emerging method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has a high robustness to field inhomogeneity and chemical shift effect. It has been broadened from single-slice scanning to multi-slice scanning. In this paper, a novel multi-slice SPEN MRI method was proposed. In this method, the slice-selective dimension was segmented to lower the specific absorption rate (SAR) and improve the image quality. This segmented method, dubbed SeSPEN method, was theoretically analyzed and demonstrated with phantom, lemon and in vivo rat brain experiments. The experimental results were compared with the results obtained from the spin-echo EPI, spin-echo SPEN method and multi-slice global SPEN method proposed by Frydman and coauthors (abbr. GlSPEN method). All the SPEN images were super-resolved reconstructed using deconvolution method. The results indicate that the SeSPEN method retains the advantage of SPEN MRI with respect to resistance to field inhomogeneity and can provide better signal-to-noise ratio than multi-slice GlSPEN MRI technique. The SeSPEN method has comparable SAR to the GlSPEN method while the T1 signal attenuation effect is alleviated. The proposed method will facilitate the multi-slice SPEN MRI to scan more slices within one scan with better image quality. PMID:27301072

  18. Ultrafast multi-slice spatiotemporally encoded MRI with slice-selective dimension segmented

    Science.gov (United States)

    Zhang, Ting; Chen, Lin; Huang, Jianpan; Li, Jing; Cai, Shuhui; Cai, Congbo; Chen, Zhong

    2016-08-01

    As a recently emerging method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has a high robustness to field inhomogeneity and chemical shift effect. It has been broadened from single-slice scanning to multi-slice scanning. In this paper, a novel multi-slice SPEN MRI method was proposed. In this method, the slice-selective dimension was segmented to lower the specific absorption rate (SAR) and improve the image quality. This segmented method, dubbed SeSPEN method, was theoretically analyzed and demonstrated with phantom, lemon and in vivo rat brain experiments. The experimental results were compared with the results obtained from the spin-echo EPI, spin-echo SPEN method and multi-slice global SPEN method proposed by Frydman and coauthors (abbr. GlSPEN method). All the SPEN images were super-resolved reconstructed using deconvolution method. The results indicate that the SeSPEN method retains the advantage of SPEN MRI with respect to resistance to field inhomogeneity and can provide better signal-to-noise ratio than multi-slice GlSPEN MRI technique. The SeSPEN method has comparable SAR to the GlSPEN method while the T1 signal attenuation effect is alleviated. The proposed method will facilitate the multi-slice SPEN MRI to scan more slices within one scan with better image quality.

  19. Circadian rhythm modulates long-term potentiation induced at CA1 in rat hippocampal slices.

    Science.gov (United States)

    Nakatsuka, Hiroki; Natsume, Kiyohisa

    2014-03-01

    Circadian rhythm affects neuronal plasticity. Consistent with this, some forms of synaptic long-term potentiation (LTP) are modulated by the light/dark cycle (LD cycle). For example, this type of modulation is observed in hippocampal slices. In rodents, which are nocturnal, LTP is usually facilitated in the dark phase, but the rat hippocampal CA1 is an exception. The reason why LTP in the dark phase is suppressed in CA1 remains unknown. Previously, LTP was induced with high-frequency stimulation. In this study, we found that in the dark phase, theta-burst stimulation-induced LTP is indeed facilitated in CA1, similar to other regions in the rodent brain. Population excitatory postsynaptic potentials (pEPSP)-LTP and population spikes (PS)-LTP were recorded at CA1. The magnitude of PS-LTP in dark-phase slices was significantly larger than in light-phase slices, while that of pEPSP-LTP was unchanged. Using antidromic-orthodromic stimulation, we found that recurrent inhibition is suppressed in the dark phase. Local gabazine-application to stratum pyramidale in light-phase slices mimicked this disinhibition and facilitated LTP in dark-phase slices. These results suggest that the disinhibition of a GABAA recurrent inhibitory network can be induced in the dark phase, thereby facilitating LTP.

  20. Effects of ketamine,midazolam,thiopental,and propofol on brain ischemia injury in rat cerebral cortical slices%氯胺酮,咪唑安定,硫喷妥钠和异丙酚对大鼠皮层脑片缺血性损伤的作用

    Institute of Scientific and Technical Information of China (English)

    薛庆生; 于布为; 王泽剑; 陈红专

    2004-01-01

    AIM: To compare the effects of ketamine, midazolam, thiopental, and propofol on brain ischemia by the model of oxygen-glucose deprivation (OGD) in rat cerebral cortical slices. METHODS: Cerebral cortical slices were incubated in 2 % 2,3,5-triphenyltetrazolium chloride (TTC) solution after OGD, the damages and effects of ketamine,midazolam, thiopental, and propofol were quantitativlye evaluated by ELISA reader of absorbance (A) at 490 nm,which indicated the red formazan extracted from slices, lactic dehydrogenase (LDH) releases in the incubated supernate were also measured. RESULTS: Progressive prolongation of OGD resulted in decreases of TTC staining.The percentage of tissue injury had a positive correlation with LDH releases, r=0.9609, P<0.01. Two hours of reincubation aggravated the decrease of TTC staining compared with those slices stained immediately after OGD (P<0.01). These four anesthetics had no effects on the TTC staining of slices. Ketamine completely inhibited the decrease of A value induced by 10 min of OGD injury. High concentrations of midazolam (10 μmol/L) and thiopental (400 μmol/L)partly attenuated this decrease. Propofol at high concentration (100 μmol/L) enhanced the decrease of A value induced by 10 min of OGD injury (P<0.01). CONCLUSION: Ketamine, high concentration of midazolam and thiopental have neuroprotective effects against OGD injury in rat cerebral cortical slices, while high concentration of propofol augments OGD injury in rat cerebral cortical slices.

  1. Simultaneous EMG-Functional MRI Recordings Can Directly Relate Hyperkinetic Movements to Brain Activity

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; Maurits, Natasha M.; Renken, Remco; Koelman, Johannes H. T. M.; Hoogduin, Johannes M.; Leenders, Klaus L.; Tijssen, Marina A. J.

    2008-01-01

    Objective: To apply and validate the use of electromyogram (EMG) recorded during functional magnetic resonance imaging (fMRI) in patients with movement disorders, to directly relate involuntary movements to brain activity. Methods: Eight "familial cortical myoclonic tremor with epilepsy" (FCMTE) pat

  2. Recording the brain at work: the visible, the readable, and the invisible in electroencephalography.

    Science.gov (United States)

    Borck, Cornelius

    2008-01-01

    The electroencephalogram (EEG), the graphic recording of the electric activity of the human brain, kindled far-reaching speculations about the imminent deciphering of mind and brain in the 1930s. Regardless of the thousands of neurons in the human cortex, recording from a person at rest produced a surprisingly regular line oscillating at 10 per second that disappeared at the moment of mental activity. With ever more groups specializing in electroencephalography, however, the deciphering of mind and brain did not materialize but moved further away in the information produced. In the various approaches employed in EEG research, such as the analysis of the graphic code, the search for pathognomic patterns or the imaging of cognitive processing, visualization guided research as well as theorizing, its productivity continued to keep the epistemological question open.

  3. High-Tc superconducting quantum interference device recordings of spontaneous brain activity: Towards high-Tc magnetoencephalography

    Science.gov (United States)

    Öisjöen, F.; Schneiderman, J. F.; Figueras, G. A.; Chukharkin, M. L.; Kalabukhov, A.; Hedström, A.; Elam, M.; Winkler, D.

    2012-03-01

    We have performed single- and two-channel high transition temperature (high-Tc) superconducting quantum interference device (SQUID) magnetoencephalography (MEG) recordings of spontaneous brain activity in two healthy human subjects. We demonstrate modulation of two well-known brain rhythms: the occipital alpha rhythm and the mu rhythm found in the motor cortex. We further show that despite higher noise-levels compared to their low-Tc counterparts, high-Tc SQUIDs can be used to detect and record physiologically relevant brain rhythms with comparable signal-to-noise ratios. These results indicate the utility of high-Tc technology in MEG recordings of a broader range of brain activity.

  4. Slicing black hole spacetimes

    CERN Document Server

    Bini, Donato; Geralico, Andrea; Jantzen, Robert T

    2015-01-01

    A general framework is developed to investigate the properties of useful choices of stationary spacelike slicings of stationary spacetimes whose congruences of timelike orthogonal trajectories are interpreted as the world lines of an associated family of observers, the kinematical properties of which in turn may be used to geometrically characterize the original slicings. On the other hand properties of the slicings themselves can directly characterize their utility motivated instead by other considerations like the initial value and evolution problems in the 3-plus-1 approach to general relativity. An attempt is made to categorize the various slicing conditions or "time gauges" used in the literature for the most familiar stationary spacetimes: black holes and their flat spacetime limit.

  5. A HYBRID DYNAMIC PROGRAM SLICING

    Institute of Scientific and Technical Information of China (English)

    Yi Tong; Wu Fangjun

    2005-01-01

    This letter proposes a hybrid method for computing dynamic program slicing. The key element is to construct a Coverage-Testing-based Dynamic Dependence Graph (CTDDG),which makes use of both dynamic and static information to get execution status. The approach overcomes the limitations of previous dynamic slicing methods, which have to redo slicing if slice criterion changes.

  6. Análise comparativa de cortes de encéfalos humanos com coloração por três técnicas diferentes Comparative analysis of human brain slices with three different staining techniques

    Directory of Open Access Journals (Sweden)

    Murilo Sousa de Meneses

    2004-06-01

    Full Text Available O estudo anatômico do encéfalo em cortes é facilitado empregando-se métodos de coloração para substância cinzenta. Os métodos mais freqüentemente empregados são os de Barnard, Robert e Brown, Mulligan e Green. O objetivo deste estudo foi determinar qual dessas técnicas apresenta melhores resultados com relação à diferenciação entre substâncias branca e cinzenta. Trinta cortes coronais de hemisfério cerebral humano foram submetidos às três técnicas, comparados entre si e analisados de acordo com três parâmetros estabelecidos: grau de diferenciação entre as substâncias branca e cinzenta; presença de linha única e contínua separando a substância branca do córtex cerebral; grau de impregnação da coloração em outros locais de substância branca. Atribuíram-se pontuações de 0 a 3 conforme a presença destes parâmetros, cada corte recebendo pontuação total que variava de 0 a 9. Após análise estatística, a técnica de Barnard, Robert e Brown apresentou média 8,33; a de Green 7,93 e a de Mulligan, 7,5, com diferença estatisticamente significativa.Studing neuroanatomy at brain slices with gray matter staining techniques has several advantages. More often, the models described by Barnard, Robert and Brown, Mulligan, and Green are used. The aim of this study was to identify which of them achieves the best results on differentiation between the gray and the white matter. Thirty coronal slices of human brains underwent staining by the three techniques, and thus compared and analysed according this three parameters: degree of differentiation between white and gray matter, presence of a single and uninterrupted line dividing the white matter from the brain cortex; and degree of impregnation of the color staining in the white matter; scores from 0 to 3 have been given for the three parameters, with total score from 0 to 9. After statistic analysis, the Barnard, Robert and Brown model showed the best results, followed

  7. A glass capillary microelectrode based on capillarity and its application to the detection of L-glutamate release from mouse brain slices.

    Science.gov (United States)

    Nakajima, Kumiko; Yamagiwa, Takashi; Hirano, Ayumi; Sugawara, Masao

    2003-01-01

    A new glass capillary microelectrode for L-glutamate is described using pulled glass capillaries (tip size, approximately 12.5 microm) with a very small volume (approximately 2 microl) of inner solution containing glutamate oxidase (GluOx) and ascorbate oxidase. The operation of the electrode is based on capillary action that samples L-glutamate into the inner solution. The enzyme reaction by GluOx generates hydrogen peroxide that is detected at an Os-gel-HRP polymer modified Pt electrode in a three-electrode configuration. The amperometric response behavior of the electrode was characterized in terms of the capillarity, response time, sensitivity and selectivity for measurements of L-glutamate. The currents at 0 V vs. Ag/AgCl increased linearly with the L-glutamate concentration from 10 to 150 microM for in vitro and in situ calibrations. The response was highly selective to L-glutamate over ascorbate, dopamine, serotonin and other amino acids. The detection of L-glutamate in the extracellular fluids of different regions of mouse hippocampal slices under stimulation of KCl was demonstrated.

  8. The Appetite-Inducing Peptide, Ghrelin, Induces Intracellular Store-Mediated Rises in Calcium in Addiction and Arousal-Related Laterodorsal Tegmental Neurons in Mouse Brain Slices

    DEFF Research Database (Denmark)

    Hauberg, Katrine; Kohlmeier, Kristi Anne

    2015-01-01

    Ghrelin, a gut and brain peptide, has recently been shown to be involved in motivated behavior and regulation of the sleep and wakefulness cycle. The laterodorsal tegmental nucleus (LDT) is involved in appetitive behavior and control of the arousal state of an organism, and accordingly, behaviora...

  9. Simultaneous multi-slice Turbo-FLASH imaging with CAIPIRINHA for whole brain distortion-free pseudo-continuous arterial spin labeling at 3 and 7 T.

    Science.gov (United States)

    Wang, Yi; Moeller, Steen; Li, Xiufeng; Vu, An T; Krasileva, Kate; Ugurbil, Kamil; Yacoub, Essa; Wang, Danny J J

    2015-06-01

    Simultaneous multi-slice (SMS) or multiband (MB) imaging has recently been attempted for arterial spin labeled (ASL) perfusion MRI in conjunction with echo-planar imaging (EPI) readout. It was found that SMS-EPI can reduce the T1 relaxation effect of the label and improve image coverage and resolution with little penalty in signal-to-noise ratio (SNR). However, EPI still suffers from geometric distortion and signal dropout from field inhomogeneity effects especially at high and ultrahigh magnetic fields. Here we present a novel scheme for achieving high fidelity distortion-free quantitative perfusion imaging by combining pseudo-continuous ASL (pCASL) with SMS Turbo-FLASH (TFL) readout at both 3 and 7 T. Bloch equation simulation was performed to characterize and optimize the TFL-based pCASL perfusion signal. Two MB factors (3 and 5) were implemented in SMS-TFL pCASL and compared with standard 2D TFL and EPI pCASL sequences. The temporal SNR of SMS-TFL pCASL relative to that of standard TFL pCASL was 0.76 ± 0.10 and 0.74 ± 0.11 at 7 T and 0.70 ± 0.05 and 0.65 ± 0.05 at 3T for MB factor of 3 and 5, respectively. By implementing background suppression in conjunction with SMS-TFL at 3T, the relative temporal SNR improved to 0.84 ± 0.09 and 0.79 ± 0.10 for MB factor of 3 and 5, respectively. Compared to EPI pCASL, significantly increased temporal SNR (pbrain distortion-free quantitative mapping of cerebral blood flow at high and ultrahigh magnetic fields.

  10. Performance of dry electrode with bristle in recording EEG rhythms across brain state changes.

    Science.gov (United States)

    Kitoko, Vangu; Nguyen, Tuan N; Nguyen, Jordan S; Tran, Yvonne; Nguyen, Hung T

    2011-01-01

    In this paper we evaluate the physiological performance of a silver-silver chloride dry electrode with bristle (B-Electrode) in recording EEG data. For this purpose, we compare the performance of the bristle electrode in recording EEG data with the standard wet gold-plated cup electrode (G-Electrode) using two different brain state change tasks including resting condition with eyes-closed and performing mathematical task with eyes-open. Using a 2 channel recording device, eyes-closed command data were collected from each of 6 participants for a period of 20 sec and the same procedure was applied for the mathematical calculation task. These data were used for statistical and classification analyse. Although, B-electrode has shown a slightly higher performance compared with G-electrode in both tasks, but analyse did not reveal any significant differences between both electrodes in all six subjects tested.

  11. Electrophysiology of hypothalamic magnocellular neurons in vitro: a rhythmic drive in organotypic cultures and acute slices

    Directory of Open Access Journals (Sweden)

    Jean-Marc eIsrael

    2016-03-01

    Full Text Available Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

  12. Decomposition of Brain Slice Image Based on Intuitive Fuzzy Sets of Artificial Fish Swarm Search%直觉模糊集人工鱼群搜索的人脑切片图像分解

    Institute of Scientific and Technical Information of China (English)

    王睿

    2014-01-01

    The micro decomposition of the brain image is the foundation of image feature analysis. Traditional artificial fish swarm algorithm (AFSA) fuses the local information, which leads to image noise enhancement. It is difficult to effectively ex-tract the numerical image feature information, so the decomposition effect is not good. An improved micro decomposition method of slice image is proposed based on intuitive fuzzy sets of artificial fish swarm search, fuzzy set theory is used, and the intuitive fuzzy set is constructed. AFSA is used to search more feature, and get the self-organization search solution. The uniformly ergodic properties is used to search global micro characteristics, without the human intervention, so it is more suitable for dealing with fuzzy and uncertain problems. It is applicable to the image micro decomposition. The brain slices with strong noise is used as the sample in experiment, results show that the algorithm has better performance in preci-sion and computational complexity.%精密的大脑切片图像的微细分解处理是进行图像特征分析的基础,传统的人工鱼群算法对图像微细区域进行分解时,融入局部信息导致图像噪声增强,难以有效提取图像的数值特征信息,分解效果不好。提出一种基于直觉模糊集的人工鱼群搜索算法,根据模糊集理论,进行直觉模糊集构造。在人工鱼群寻优搜索到的引领粒子附近自组织搜索更优特征解,利用直觉模糊集的均匀遍历特性全局搜索微细特征,不需要人为的干预,更适合处理一些模糊的和不确定的问题,适用于图像的微细分解。仿真实验得出该算法在处理含强噪声的脑切片图像时,微细分解精度很好,精度和计算复杂度等方面较传统方法有优越性。

  13. Uni- and multisensory brain areas are synchronised across spectators when watching unedited dance recordings.

    Science.gov (United States)

    Jola, Corinne; McAleer, Phil; Grosbras, Marie-Hélène; Love, Scott A; Morison, Gordon; Pollick, Frank E

    2013-01-01

    The superior temporal sulcus (STS) and gyrus (STG) are commonly identified to be functionally relevant for multisensory integration of audiovisual (AV) stimuli. However, most neuroimaging studies on AV integration used stimuli of short duration in explicit evaluative tasks. Importantly though, many of our AV experiences are of a long duration and ambiguous. It is unclear if the enhanced activity in audio, visual, and AV brain areas would also be synchronised over time across subjects when they are exposed to such multisensory stimuli. We used intersubject correlation to investigate which brain areas are synchronised across novices for uni- and multisensory versions of a 6-min 26-s recording of an unfamiliar, unedited Indian dance recording (Bharatanatyam). In Bharatanatyam, music and dance are choreographed together in a highly intermodal-dependent manner. Activity in the middle and posterior STG was significantly correlated between subjects and showed also significant enhancement for AV integration when the functional magnetic resonance signals were contrasted against each other using a general linear model conjunction analysis. These results extend previous studies by showing an intermediate step of synchronisation for novices: while there was a consensus across subjects' brain activity in areas relevant for unisensory processing and AV integration of related audio and visual stimuli, we found no evidence for synchronisation of higher level cognitive processes, suggesting these were idiosyncratic. PMID:24349687

  14. Slicing, skinning, and grafting

    OpenAIRE

    Dumas, David; Kent IV, Richard P.

    2007-01-01

    We prove that a Bers slice is never algebraic, meaning that its Zariski closure in the character variety has strictly larger dimension. A corollary is that skinning maps are never constant. The proof uses grafting and the theory of complex projective structures.

  15. Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.

    Science.gov (United States)

    Anand, Sindhu; Kumar, Swathy Sampath; Muthuswamy, Jit

    2016-08-01

    Emerging neural prosthetics require precise positional tuning and stable interfaces with single neurons for optimal function over a lifetime. In this study, we report an autonomous control to precisely navigate microscale electrodes in soft, viscoelastic brain tissue without visual feedback. The autonomous control optimizes signal-to-noise ratio (SNR) of single neuronal recordings in viscoelastic brain tissue while maintaining quasi-static mechanical stress conditions to improve stability of the implant-tissue interface. Force-displacement curves from microelectrodes in in vivo rodent experiments are used to estimate viscoelastic parameters of the brain. Using a combination of computational models and experiments, we determined an optimal movement for the microelectrodes with bidirectional displacements of 3:2 ratio between forward and backward displacements and a inter-movement interval of 40 s for minimizing mechanical stress in the surrounding brain tissue. A regulator with the above optimal bidirectional motion for the microelectrodes in in vivo experiments resulted in significant reduction in the number of microelectrode movements (0.23 movements/min) and longer periods of stable SNR (53 % of the time) compared to a regulator using a conventional linear, unidirectional microelectrode movement (with 1.48 movements/min and stable SNR 23 % of the time). PMID:27457752

  16. Brain-computer interfaces: an overview of the hardware to record neural signals from the cortex.

    Science.gov (United States)

    Stieglitz, Thomas; Rubehn, Birthe; Henle, Christian; Kisban, Sebastian; Herwik, Stanislav; Ruther, Patrick; Schuettler, Martin

    2009-01-01

    Brain-computer interfaces (BCIs) record neural signals from cortical origin with the objective to control a user interface for communication purposes, a robotic artifact or artificial limb as actuator. One of the key components of such a neuroprosthetic system is the neuro-technical interface itself, the electrode array. In this chapter, different designs and manufacturing techniques will be compared and assessed with respect to scaling and assembling limitations. The overview includes electroencephalogram (EEG) electrodes and epicortical brain-machine interfaces to record local field potentials (LFPs) from the surface of the cortex as well as intracortical needle electrodes that are intended to record single-unit activity. Two exemplary complementary technologies for micromachining of polyimide-based arrays and laser manufacturing of silicone rubber are presented and discussed with respect to spatial resolution, scaling limitations, and system properties. Advanced silicon micromachining technologies have led to highly sophisticated intracortical electrode arrays for fundamental neuroscientific applications. In this chapter, major approaches from the USA and Europe will be introduced and compared concerning complexity, modularity, and reliability. An assessment of the different technological solutions comparable to a strength weaknesses opportunities, and threats (SWOT) analysis might serve as guidance to select the adequate electrode array configuration for each control paradigm and strategy to realize robust, fast, and reliable BCIs. PMID:19660664

  17. A compact and autoclavable system for acute extracellular neural recording and brain pressure monitoring for humans.

    Science.gov (United States)

    Angotzi, Gian Nicola; Baranauskas, Gytis; Vato, Alessandro; Bonfanti, Andrea; Zambra, Guido; Maggiolini, Emma; Semprini, Marianna; Ricci, Davide; Ansaldo, Alberto; Castagnola, Elisa; Ius, Tamara; Skrap, Miran; Fadiga, Luciano

    2015-02-01

    One of the most difficult tasks for the surgeon during the removal of low-grade gliomas is to identify as precisely as possible the borders between functional and non-functional brain tissue with the aim of obtaining the maximal possible resection which allows to the patient the longer survival. For this purpose, systems for acute extracellular recordings of single neuron and multi-unit activity are considered promising. Here we describe a system to be used with 16 microelectrodes arrays that consists of an autoclavable headstage, a built-in inserter for precise electrode positioning and a system that measures and controls the pressure exerted by the headstage on the brain with a twofold purpose: to increase recording stability and to avoid disturbance of local perfusion which would cause a degradation of the quality of the recording and, eventually, local ischemia. With respect to devices where only electrodes are autoclavable, our design permits the reduction of noise arising from long cable connections preserving at the same time the flexibility and avoiding long-lasting gas sterilization procedures. Finally, size is much smaller and set up time much shorter compared to commercial systems currently in use in surgery rooms, making it easy to consider our system very useful for intra-operatory mapping operations. PMID:25486648

  18. BRAIN DYSFUNCTION OF PATIENTS WITH QIGONG INDUCED MENTAL DISORDER REVEALED BY EVOKED POTENTIALS RECORDING

    Institute of Scientific and Technical Information of China (English)

    LU Yingzhi; ZONG Wenbin; CHEN Xingshi

    2003-01-01

    Objective: In order to investigate the brain function of patients with Qigong induced mental disorder (QIMD), this study was carried out. Methods: Four kinds of evoked potentials, including contingent negative variation (CNV), auditory evoked potentials (AEP), visual evoked potentials (VEP), and somatosensory evoked potentials (SEP), were recorded from 12 patients with Qigong induced mental disorder.Comparison of their evoked potentials with the data from some normal controls was made. Results: The results revealed that there were 3 kinds of abnormal changes in evoked potentials of patients with QIMD that is latency prolongation, amplitude increase and amplitude decrease, as compared with normal controls. Conclusion: Brain dysfunction of patients with QIMD was confirmed. Its biological mechanism needs further studying.

  19. Inhibition of spontaneous network activity in neonatal hippocampal slices by energy substrates is not correlated with intracellular acidification.

    Science.gov (United States)

    Mukhtarov, Marat; Ivanov, Anton; Zilberter, Yuri; Bregestovski, Piotr

    2011-01-01

    Several energy substrates complementary to glucose, including lactate, pyruvate and β-hydroxybutyrate, serve as a fuel for neurons. It was reported recently that these substrates can substantially modulate cortical excitability in neonatal slices. However, complementary energy substrates (CES) can also induce an intracellular acidification when added exogenously. Therefore, action of CES on the neuronal properties governing excitability in neonatal brain slices may be underlain by a change in the cell energy status or by intracellular acidification, or both. Here, we attempt to elucidate these possibilities in neonatal hippocampus by recording neuronal population activity and monitoring intracellular pH. We show that a spontaneous network activity pattern, giant depolarizing potentials (GDPs), characteristic for the neonatal hippocampal slices exposed to artificial cerebrospinal fluid, is strongly inhibited by CES and this effect is unlikely to be caused by a subtle intracellular acidification induced by these compounds. Indeed, a much stronger intracellular acidification in the HCO(3) -free solution inhibited neither the GDP frequency nor the GDP amplitude. Therefore, modulation of neuronal energy homeostasis is the most likely factor underlying the effect of lactate, pyruvate and β-hydroxybutyrate on network excitability in neonatal brain slices.

  20. Slice profile distortions in single slice continuously moving table MRI

    Science.gov (United States)

    Sengupta, Saikat; Smith, David S.; Welch, E. B.

    2015-03-01

    Continuously Moving Table (CMT) MRI is a rapid imaging technique that allows scanning of extended fields of view (FOVs) such as the whole-body in a single continuous scan.1 A highly efficient approach to CMT MRI is single slice imaging, where data are continuously acquired from a single axial slice at isocenter with concurrent movement of the patient table.2 However, the continuous motion of the scanner table and supply of fresh magnetization into the excited slice can introduce deviations in the slice magnetization profile. The goal of this work is to investigate and quantify the distortion in the slice profile in CMT MRI. CMT MRI with a table speed of 20 mm/s was implemented on a 3 Tesla whole-body MRI scanner, with continuous radial data acquisition. Simulations were performed to characterize the transient and steady state slice profiles and magnetization effects. Simulated slice profiles were compared to actual slice profile measurements performed in the scanner. Both simulations and experiments revealed an asymmetric slice profile characterized by a skew towards the lagging edge of the moving table, in contrast to the nominal profiles associated with scanning a stationary object. The true excited slice width (FWHM) and pitch of the acquisition was observed to be dependent on table velocity, with larger table speeds resulting in larger slice profile deviations from the nominal shape.

  1. Scanning Electron Microscopy Structure and Firmness of Papain Treated Apple Slices

    OpenAIRE

    Luo, Yaguang; Patterson, Max E.; Swanson, Barry G.

    1992-01-01

    'Mcintosh' apple (Malus domesrica Borkh.) slices were treated with papain. Textural changes were recorded with an Instron Universal Testing Machine. Structural changes and distribution of microorganisms in apple tissues after treatment were observed with a scanning electron microscope (SEM). Apple slices submerg ed in a 1% papain solution were significantly firmer than apple slices submerged in the distilled water control for a 24 hour period (P < 0.05). Three and four days after slicing , a ...

  2. Instrumentation to record evoked potentials for closed-loop control of deep brain stimulation.

    Science.gov (United States)

    Kent, Alexander R; Grill, Warren M

    2011-01-01

    Closed-loop deep brain stimulation (DBS) systems offer promise in relieving the clinical burden of stimulus parameter selection and improving treatment outcomes. In such a system, a feedback signal is used to adjust automatically stimulation parameters and optimize the efficacy of stimulation. We explored the feasibility of recording electrically evoked compound action potentials (ECAPs) during DBS for use as a feedback control signal. A novel instrumentation system was developed to suppress the stimulus artifact and amplify the small magnitude, short latency ECAP response during DBS with clinically relevant parameters. In vitro testing demonstrated the capabilities to increase the gain by a factor of 1,000× over a conventional amplifier without saturation, reduce distortion of mock ECAP signals, and make high fidelity recordings of mock ECAPs at latencies of only 0.5 ms following DBS pulses of 50 to 100 μs duration. Subsequently, the instrumentation was used to make in vivo recordings of ECAPs during thalamic DBS in cats, without contamination by the stimulus artifact. The signal characteristics were similar across three experiments, suggesting common neural activation patterns. The ECAP recordings enabled with this novel instrumentation may provide insight into the type and spatial extent of neural elements activated during DBS, and could serve as feedback control signals for closed-loop systems. PMID:22255894

  3. Intrinsic control of electroresponsive properties of transplanted mammalian brain neurons

    DEFF Research Database (Denmark)

    Hounsgaard, J; Yarom, Y

    1985-01-01

    The present study presents the first analysis of neurons in mammalian brain transplants based on intracellular recording. The results, obtained in brain slices including both donor and host tissue, showed that neuronal precursor cells in embryonic transplants retained their ability to complete...... their normal differentiation of cell-type-specific electroresponsive properties. Distortions in cell aggregation and synaptic connectivity did not affect this aspect of neuronal differentiation....

  4. Correlation of 64-slices CT Features with Vascular Endothelial Growth Factor Expression in Brain Astrocytoma%VEGF在脑星形细胞瘤中的表达与64排CT征象的关系

    Institute of Scientific and Technical Information of China (English)

    蔡胜艳; 孙妍; 胡嘉航

    2012-01-01

    目的:探讨脑星形细胞瘤64排CT征象与VEGF表达之间的关系.方法:搜集经手术证实的脑星形细胞瘤30例,分析其CT表现,术后对肿瘤组织标本进行免疫组化染色,分析其VEGF表达的程度与CT征象之间的关系.结果:星形细胞瘤的VEGF表达程度与肿瘤的分级、瘤周水肿的范围及肿瘤的强化程度有相关性.结论:星形细胞瘤的CT表现可以反映VEGF的表达程度,能对临床治疗方案的选择和患者预后的评估起到重要作用.%Objective To study the correlation of 64-slices CT features with vascular endolhelial growth factor(VEGF) expression in brain astrocytoma. Methods CT findings in 30 cases with surgically and pathologically proved astrocytoma were retrospectively analyzed. VEGF was stained with immuno- histochemical technique, and VEGF expression levels were compared with CTfeatures. Results VEGF expression levels were with correlated with pathological grade, the extent of per tumor edema and the degree of contrast enhancement. Conclusion CT features of astrocytoma can reflect VEGF expression levels. It is important for the choice of clinical treatment and prognostic evaluation of patients. [Chinese Medical Equipment Journal,2012,33(6):67-68

  5. Brain

    Science.gov (United States)

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

  6. Tracking Single Units in Chronic, Large Scale, Neural Recordings for Brain Machine Interface Applications

    Directory of Open Access Journals (Sweden)

    Ahmed eEleryan

    2014-07-01

    Full Text Available In the study of population coding in neurobiological systems, tracking unit identity may be critical to assess possible changes in the coding properties of neuronal constituents over prolonged periods of time. Ensuring unit stability is even more critical for reliable neural decoding of motor variables in intra-cortically controlled brain-machine interfaces (BMIs. Variability in intrinsic spike patterns, tuning characteristics, and single-unit identity over chronic use is a major challenge to maintaining this stability, requiring frequent daily calibration of neural decoders in BMI sessions by an experienced human operator. Here, we report on a unit-stability tracking algorithm that efficiently and autonomously identifies putative single-units that are stable across many sessions using a relatively short duration recording interval at the start of each session. The algorithm first builds a database of features extracted from units' average spike waveforms and firing patterns across many days of recording. It then uses these features to decide whether spike occurrences on the same channel on one day belong to the same unit recorded on another day or not. We assessed the overall performance of the algorithm for different choices of features and classifiers trained using human expert judgment, and quantified it as a function of accuracy and execution time. Overall, we found a trade-off between accuracy and execution time with increasing data volumes from chronically implanted rhesus macaques, with an average of 12 seconds processing time per channel at ~90% classification accuracy. Furthermore, 77% of the resulting putative single-units matched those tracked by human experts. These results demonstrate that over the span of a few months of recordings, automated unit tracking can be performed with high accuracy and used to streamline the calibration phase during BMI sessions.

  7. Development of brain damage as measured by brain impedance recordings, and changes in heart rate, and blood pressure induced by different stunning and killing methods.

    Science.gov (United States)

    Savenije, B; Lambooij, E; Gerritzen, M A; Korf, J

    2002-04-01

    Poultry are electrically stunned before slaughter to induce unconsciousness and to immobilize the chickens for easier killing. From a welfare point of view, electrical stunning should induce immediate and lasting unconsciousness in the chicken. As an alternative to electroencephalography, which measures brain electrical activity, this study used brain impedance recordings, which measure brain metabolic activity, to determine the onset and development of brain damage. Fifty-six chickens were surgically equipped with brain electrodes and a canula in the wing artery and were subjected to one of seven stunning and killing methods: whole body electrical stunning; head-only electrical stunning at 50, 100 or 150 V; or an i.v. injection with MgCl2. After 30 s, the chickens were exsanguinated. Brain impedance and blood pressure were measured. Extracellular volume was determined from the brain impedance data and heart rate from the blood pressure data. An immediate and progressive reduction in extracellular volume in all chickens was found only with whole body stunning at 150 V. This treatment also caused cardiac fibrillation or arrest in all chickens. With all other electrical stunning treatments, extracellular volume was immediately reduced in some but not all birds, and cardiac fibrillation or arrest was not often found. Ischemic conditions, caused by cessation of the circulation, stimulated this epileptic effect. A stunner setting of 150 V is therefore recommended to ensure immediate and lasting unconsciousness, which is a requirement for humane slaughter. PMID:11989758

  8. Scale-Free Brain-Wave Music from Simultaneously EEG and fMRI Recordings

    Science.gov (United States)

    Lu, Jing; Wu, Dan; Yang, Hua; Luo, Cheng; Li, Chaoyi; Yao, Dezhong

    2012-01-01

    In the past years, a few methods have been developed to translate human EEG to music. In 2009, PloS One 4 e5915, we developed a method to generate scale-free brainwave music where the amplitude of EEG was translated to music pitch according to the power law followed by both of them, the period of an EEG waveform is translated directly to the duration of a note, and the logarithm of the average power change of EEG is translated to music intensity according to the Fechner's law. In this work, we proposed to adopt simultaneously-recorded fMRI signal to control the intensity of the EEG music, thus an EEG-fMRI music is generated by combining two different and simultaneous brain signals. And most importantly, this approach further realized power law for music intensity as fMRI signal follows it. Thus the EEG-fMRI music makes a step ahead in reflecting the physiological process of the scale-free brain. PMID:23166768

  9. Scale-free brain-wave music from simultaneously EEG and fMRI recordings.

    Science.gov (United States)

    Lu, Jing; Wu, Dan; Yang, Hua; Luo, Cheng; Li, Chaoyi; Yao, Dezhong

    2012-01-01

    In the past years, a few methods have been developed to translate human EEG to music. In 2009, PloS One 4 e5915, we developed a method to generate scale-free brainwave music where the amplitude of EEG was translated to music pitch according to the power law followed by both of them, the period of an EEG waveform is translated directly to the duration of a note, and the logarithm of the average power change of EEG is translated to music intensity according to the Fechner's law. In this work, we proposed to adopt simultaneously-recorded fMRI signal to control the intensity of the EEG music, thus an EEG-fMRI music is generated by combining two different and simultaneous brain signals. And most importantly, this approach further realized power law for music intensity as fMRI signal follows it. Thus the EEG-fMRI music makes a step ahead in reflecting the physiological process of the scale-free brain. PMID:23166768

  10. Patch-clamp capacitance measurements and Ca²⁺ imaging at single nerve terminals in retinal slices.

    Science.gov (United States)

    Kim, Mean-Hwan; Vickers, Evan; von Gersdorff, Henrique

    2012-01-01

    Visual stimuli are detected and conveyed over a wide dynamic range of light intensities and frequency changes by specialized neurons in the vertebrate retina. Two classes of retinal neurons, photoreceptors and bipolar cells, accomplish this by using ribbon-type active zones, which enable sustained and high-throughput neurotransmitter release over long time periods. ON-type mixed bipolar cell (Mb) terminals in the goldfish retina, which depolarize to light stimuli and receive mixed rod and cone photoreceptor input, are suitable for the study of ribbon-type synapses both due to their large size (~10-12 μm diameter) and to their numerous lateral and reciprocal synaptic connections with amacrine cell dendrites. Direct access to Mb bipolar cell terminals in goldfish retinal slices with the patch-clamp technique allows the measurement of presynaptic Ca(2+) currents, membrane capacitance changes, and reciprocal synaptic feedback inhibition mediated by GABA(A) and GABA(C) receptors expressed on the terminals. Presynaptic membrane capacitance measurements of exocytosis allow one to study the short-term plasticity of excitatory neurotransmitter release. In addition, short-term and long-term plasticity of inhibitory neurotransmitter release from amacrine cells can also be investigated by recordings of reciprocal feedback inhibition arriving at the Mb terminal. Over short periods of time (e.g. ~10 s), GABAergic reciprocal feedback inhibition from amacrine cells undergoes paired-pulse depression via GABA vesicle pool depletion. The synaptic dynamics of retinal microcircuits in the inner plexiform layer of the retina can thus be directly studied. The brain-slice technique was introduced more than 40 years ago but is still very useful for the investigation of the electrical properties of neurons, both at the single cell soma, single dendrite or axon, and microcircuit synaptic level. Tissues that are too small to be glued directly onto the slicing chamber are often first embedded

  11. Semi-automatic microdrive system for positioning electrodes during electrophysiological recordings from rat brain

    Science.gov (United States)

    Dabrowski, Piotr; Kublik, Ewa; Mozaryn, Jakub

    2015-09-01

    Electrophysiological recording of neuronal action potentials from behaving animals requires portable, precise and reliable devices for positioning of multiple microelectrodes in the brain. We propose a semi-automatic microdrive system for independent positioning of up to 8 electrodes (or tetrodes) in a rat (or larger animals). Device is intended to be used in chronic, long term recording applications in freely moving animals. Our design is based on independent stepper motors with lead screws which will offer single steps of ~ μm semi-automatically controlled from the computer. Microdrive system prototype for one electrode was developed and tested. Because of the lack of the systematic test procedures dedicated to such applications, we propose the evaluation of the prototype similar to ISO norm for industrial robots. To this end we designed and implemented magnetic linear and rotary encoders that provided information about electrode displacement and motor shaft movement. On the basis of these measurements we estimated repeatability, accuracy and backlash of the drive. According to the given assumptions and preliminary tests, the device should provide greater accuracy than hand-controlled manipulators available on the market. Automatic positioning will also shorten the course of the experiment and improve the acquisition of signals from multiple neuronal populations.

  12. RESULTS OF SLICE MEASUREMENTS

    CERN Document Server

    Rudolph, J

    2011-01-01

    The linear accelerator ELBE delivers high-brightness electron bunches to multiple user stations, including two IR-FEL oscillators [1], [2]. In the framework of an upgrade program the current thermionic injector is being replaced by a SRF-photoinjector [3], [4]. The SRF injector promises higher beam quality, especially required for future experiments with high power laser radiation. During the commissioning phase, the SRF-injector was running in parallel to the thermionic gun. After installation of a injection beamline (dogleg), beam from the SRF-injector can now be injected into the ELBE linac. Detailed characterization of the electron beam quality delivered by the new electron injector includes vertical slice emittance measurements in addition to measurements of projected emittance values. This report gives an overview of the status of the project and summarizes first measurement results as well as results of simulations performed with measurement settings.

  13. A quantitative comparison of simultaneous BOLD fMRI and NIRS recordings during functional brain activation

    Science.gov (United States)

    Strangman, Gary; Culver, Joseph P.; Thompson, John H.; Boas, David A.; Sutton, J. P. (Principal Investigator)

    2002-01-01

    Near-infrared spectroscopy (NIRS) has been used to noninvasively monitor adult human brain function in a wide variety of tasks. While rough spatial correspondences with maps generated from functional magnetic resonance imaging (fMRI) have been found in such experiments, the amplitude correspondences between the two recording modalities have not been fully characterized. To do so, we simultaneously acquired NIRS and blood-oxygenation level-dependent (BOLD) fMRI data and compared Delta(1/BOLD) (approximately R(2)(*)) to changes in oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentrations derived from the NIRS data from subjects performing a simple motor task. We expected the correlation with deoxyhemoglobin to be strongest, due to the causal relation between changes in deoxyhemoglobin concentrations and BOLD signal. Instead we found highly variable correlations, suggesting the need to account for individual subject differences in our NIRS calculations. We argue that the variability resulted from systematic errors associated with each of the signals, including: (1) partial volume errors due to focal concentration changes, (2) wavelength dependence of this partial volume effect, (3) tissue model errors, and (4) possible spatial incongruence between oxy- and deoxyhemoglobin concentration changes. After such effects were accounted for, strong correlations were found between fMRI changes and all optical measures, with oxyhemoglobin providing the strongest correlation. Importantly, this finding held even when including scalp, skull, and inactive brain tissue in the average BOLD signal. This may reflect, at least in part, the superior contrast-to-noise ratio for oxyhemoglobin relative to deoxyhemoglobin (from optical measurements), rather than physiology related to BOLD signal interpretation.

  14. Thyrotropin-releasing hormone (TRH) depolarizes a subset of inspiratory neurons in the newborn mouse brain stem in vitro

    DEFF Research Database (Denmark)

    Rekling, J C; Champagnat, J; Denavit-Saubié, M

    1996-01-01

    in a thick brain stem slice preparation from the newborn mouse. The action of TRH on the respiratory output from the slice was investigated by recordings from the XII nerve. Cellular responses to TRH were investigated using whole cell recordings from hypoglossal motoneurons and three types of inspiratory...... neurons located in the rostral ventrolateral part of the slice. 2. Bath-applied TRH (1 microM) decreased the time between inspiratory discharges recorded on the XII nerve from 12.3 +/- 3.3 s to 4.9 +/- 1.1 s (n = 28; means +/- SD), i.e., caused an approximate threefold increase in the respiratory...... mice through an action at the level of the brain stem.(ABSTRACT TRUNCATED AT 250 WORDS)...

  15. Long-term neural recordings using MEMS based moveable microelectrodes in the brain

    Directory of Open Access Journals (Sweden)

    Nathan Jackson

    2010-06-01

    Full Text Available One of the critical requirements of the emerging class of neural prosthetic devices is to maintain good quality neural recordings over long time periods. We report here a novel (Micro-ElectroMechanical Systems based technology that can move microelectrodes in the event of deterioration in neural signal to sample a new set of neurons. Microscale electro-thermal actuators are used to controllably move microelectrodes post-implantation in steps of approximately 9 µm. In this study, a total of 12 moveable microelectrode chips were individually implanted in adult rats. Two of the 12 moveable microelectrode chips were not moved over a period of 3 weeks and were treated as control experiments. During the first three weeks of implantation, moving the microelectrodes led to an improvement in the average SNR from 14.61 ± 5.21 dB before movement to 18.13 ± 4.99 dB after movement across all microelectrodes and all days. However, the average RMS values of noise amplitudes were similar at 2.98 ± 1.22 µV and 3.01 ± 1.16 µV before and after microelectrode movement. Beyond three weeks, the primary observed failure mode was biological rejection of the PMMA (dental cement based skull mount resulting in the device loosening and eventually falling from the skull. Additionally, the average SNR for functioning devices beyond three weeks was 11.88 ± 2.02 dB before microelectrode movement and was significantly different (p<0.01 from the average SNR of 13.34 ± 0.919 dB after movement. The results of this study demonstrate that MEMS based technologies can move microelectrodes in rodent brains in long-term experiments resulting in improvements in signal quality. Further improvements in packaging and surgical techniques will potentially enable movable microelectrodes to record cortical neuronal activity in chronic experiments.

  16. Localization of brain activity during auditory verbal short-term memory derived from magnetic recordings.

    Science.gov (United States)

    Starr, A; Kristeva, R; Cheyne, D; Lindinger, G; Deecke, L

    1991-09-01

    We have studied magnetic and electrical fields of the brain in normal subjects during the performance of an auditory verbal short-term memory task. On each trial 3 digits, selected from the numbers 'one' through 'nine', were presented for memorization followed by a probe number which could or could not be a member of the preceding memory set. The subject pressed an appropriate response button and accuracy and reaction time were measured. Magnetic fields recorded from up to 63 sites over both hemispheres revealed a transient field at 110 ms to both the memory item and the probe consistent with a dipole source in Heschl's gyrus; a sustained magnetic field between 300 and 800 ms to just the memory items localized to the temporal lobe slightly deeper and posterior to Heschl's gyri; and a sustained magnetic field between 300 and 800 ms to just the probes localized bilaterally to the medio-basal temporal lobes. These results are related to clinical disorders of short-term memory in man.

  17. Is there a tape recorder in your head? How the brain stores and retrieves musical melodies

    Directory of Open Access Journals (Sweden)

    Josef P Rauschecker

    2014-08-01

    Full Text Available Music consists of strings of sound that vary over time. Technical devices, such as tape recorders, store musical melodies by transcribing event times of temporal sequences into consecutive locations on the storage medium. Playback occurs by reading out the stored information in the same sequence. However, it is unclear how the brain stores and retrieves auditory sequences. Neurons in the anterior lateral belt of auditory cortex are sensitive to the combination of sound features in time, but the integration time of these neurons is not sufficient to store longer sequences that stretch over several seconds, minutes or more. Functional imaging studies in humans provide evidence that music is stored instead within the auditory dorsal stream, including premotor and prefrontal areas. In monkeys, these areas are the substrate for learning of motor sequences. It appears, therefore, that the auditory dorsal stream transforms musical into motor sequence information and vice versa, realizing what are known as forward and inverse models. The basal ganglia and the cerebellum are involved in setting up the sensorimotor associations, translating timing information into spatial codes and back again.

  18. A novel formal approach to program slicing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Program slicing is a well-known program analysis technique that extracts the elements of a program related to a particular computation. The current slicing methods, however, are singular (mainly based on a program or system dependence graph), and lack good reusability and flexibility. In this paper, we present a novel formal method for program slicing, modular monadic program slicing, which abstracts the computation of program slicing as a slice monad transformer, and applies it to semantic descriptions of the program analyzed in a modular way, forming the corresponding monadic slicing algorithms. The modular abstraction mechanism allows our slicing method to possess excellent modularity and language-flexibility properties. We also give the related axioms of our slice monad transformer, the proof of the correctness and the implementation of monadic slicing algorithms. We reveal the relations of our algorithms and graph-reachable slicing algorithms.

  19. Slice-selective J-coupled coherence transfer using symmetric linear phase pulses: applications to localized GABA spectroscopy

    Science.gov (United States)

    Shen, Jun

    2003-07-01

    Symmetric, linear phase, slice-selective RF pulses were analyzed theoretically for performing slice-selective coherence transfer. It was shown using numerical simulations of product operators that, when a prefocusing gradient of the same area as that of the refocusing gradient is added, these pulses become slice-selective universal rotator pulses, therefore, capable of performing slice-selective coherence transfer. As an example, a slice-selective universal rotator pulse based on a seven-lobe hamming-filtered sinc pulse was applied to in vivo single-shot simultaneous spectral editing and spatial localization of neurotransmitter GABA in the human brain.

  20. Slice Fourier transform and convolutions

    OpenAIRE

    Cnudde, Lander; De Bie, Hendrik

    2015-01-01

    Recently the construction of various integral transforms for slice monogenic functions has gained a lot of attention. In line with these developments, the article at hand introduces the slice Fourier transform. In the first part, the kernel function of this integral transform is constructed using the Mehler formula. An explicit expression for the integral transform is obtained and allows for the study of its properties. In the second part, two kinds of corresponding convolutions are examined:...

  1. ISIR: Independent Sliced Inverse Regression

    OpenAIRE

    Li, Kevin

    2013-01-01

    International audience In this paper we consider a semiparametric regression model involving a $p$-dimensional explanatory variable ${\\mathbf{x}}$ and including a dimension reduction of ${\\mathbf{x}}$ via an index $B'{\\mathbf{x}}$. In this model, the main goal is to estimate $B$ and to predict the real response variable $Y$ conditionally to ${\\mathbf{x}}$. A standard approach is based on sliced inverse regression (SIR). We propose a new version of this method: the independent sliced invers...

  2. A Model for Slicing JAVA Programs Hierarchically

    Institute of Scientific and Technical Information of China (English)

    Bi-Xin Li; Xiao-Cong Fan; Jun Pang; Jian-Jun Zhao

    2004-01-01

    Program slicing can be effectively used to debug, test, analyze, understand and maintain objectoriented software. In this paper, a new slicing model is proposed to slice Java programs based on their inherent hierarchical feature. The main idea of hierarchical slicing is to slice programs in a stepwise way, from package level, to class level, method level, and finally up to statement level. The stepwise slicing algorithm and the related graph reachability algorithms are presented, the architecture of the Java program Analyzing Tool (JATO) based on hierarchical slicing model is provided, the applications and a small case study are also discussed.

  3. Modulating Hippocampal Plasticity with In Vivo Brain Stimulation

    OpenAIRE

    Joyce G Rohan; Carhuatanta, Kim A.; McInturf, Shawn M.; Miklasevich, Molly K.; Jankord, Ryan

    2015-01-01

    Investigations into the use of transcranial direct current stimulation (tDCS) in relieving symptoms of neurological disorders and enhancing cognitive or motor performance have exhibited promising results. However, the mechanisms by which tDCS effects brain function remain under scrutiny. We have demonstrated that in vivo tDCS in rats produced a lasting effect on hippocampal synaptic plasticity, as measured using extracellular recordings. Ex vivo preparations of hippocampal slices from rats th...

  4. Trimethyltin (TMT) neurotoxicity in organotypic rat hippocampal slice cultures

    DEFF Research Database (Denmark)

    Noraberg, J; Gramsbergen, J B; Fonnum, F;

    1998-01-01

    The neurotoxic effects of trimethyltin (TMT) on the hippocampus have been extensively studied in vivo. In this study, we examined whether the toxicity of TMT to hippocampal neurons could be reproduced in organotypic brain slice cultures in order to test the potential of this model for neurotoxico......The neurotoxic effects of trimethyltin (TMT) on the hippocampus have been extensively studied in vivo. In this study, we examined whether the toxicity of TMT to hippocampal neurons could be reproduced in organotypic brain slice cultures in order to test the potential of this model...... for neurotoxicological studies, including further studies of neurotoxic mechanisms of TMT. Four-week-old cultures, derived from 7-day-old donor rats and grown in serum-free medium, were exposed to TMT (0.5-100 microM) for 24 h followed by 24 h in normal medium. TMT-induced neurodegeneration was then monitored by (a...

  5. Correction of misaligned slices in multi-slice cardiovascular magnetic resonance using slice-to-volume registration

    OpenAIRE

    Hawkes David J; Schnabel Julia A; Netsch Thomas; Pinder Richard J; Chandler Adam G; Hill Derek LG; Razavi Reza

    2008-01-01

    Abstract A popular technique to reduce respiratory motion for cardiovascular magnetic resonance is to perform a multi-slice acquisition in which a patient holds their breath multiple times during the scan. The feasibility of rigid slice-to-volume registration to correct for misalignments of slice stacks in such images due to differing breath-hold positions is explored. Experimental results indicate that slice-to-volume registration can compensate for the typical misalignments expected. Correc...

  6. Recording evoked potentials during deep brain stimulation: development and validation of instrumentation to suppress the stimulus artefact

    Science.gov (United States)

    Kent, A. R.; Grill, W. M.

    2012-06-01

    The clinical efficacy of deep brain stimulation (DBS) for the treatment of movement disorders depends on the identification of appropriate stimulation parameters. Since the mechanisms of action of DBS remain unclear, programming sessions can be time consuming, costly and result in sub-optimal outcomes. Measurement of electrically evoked compound action potentials (ECAPs) during DBS, generated by activated neurons in the vicinity of the stimulating electrode, could offer insight into the type and spatial extent of neural element activation and provide a potential feedback signal for the rational selection of stimulation parameters and closed-loop DBS. However, recording ECAPs presents a significant technical challenge due to the large stimulus artefact, which can saturate recording amplifiers and distort short latency ECAP signals. We developed DBS-ECAP recording instrumentation combining commercial amplifiers and circuit elements in a serial configuration to reduce the stimulus artefact and enable high fidelity recording. We used an electrical circuit equivalent model of the instrumentation to understand better the sources of the stimulus artefact and the mechanisms of artefact reduction by the circuit elements. In vitro testing validated the capability of the instrumentation to suppress the stimulus artefact and increase gain by a factor of 1000 to 5000 compared to a conventional biopotential amplifier. The distortion of mock ECAP (mECAP) signals was measured across stimulation parameters, and the instrumentation enabled high fidelity recording of mECAPs with latencies of only 0.5 ms for DBS pulse widths of 50 to 100 µs/phase. Subsequently, the instrumentation was used to record in vivo ECAPs, without contamination by the stimulus artefact, during thalamic DBS in an anesthetized cat. The characteristics of the physiological ECAP were dependent on stimulation parameters. The novel instrumentation enables high fidelity ECAP recording and advances the potential use

  7. Identification and two-photon imaging of oligodendrocyte in CA1 region of hippocampal slices

    International Nuclear Information System (INIS)

    Oligodendrocyte (OL) plays a critical role in myelination and axon maintenance in central nervous system. Recent studies show that OL can also express NMDA receptors in development and pathological situations in white matter. There is still lack of studies about OL properties and function in gray matter of brain. Here we reported that some glial cells in CA1 region of rat hippocampal slices (P15-23) had distinct electrophysiological characteristics from the other glia cells in this region, while they displayed uniform properties with OL from white matter in previous report; therefore, they were considered as OL in hippocampus. By loading dye in recording pipette and imaging with two-photon laser scanning microscopy, we acquired the high spatial resolution, three-dimension images of these special cells in live slices. The OL in hippocampus shows a complex process-bearing shape and the distribution of several processes is parallel to Schaffer fiber in CA1 region. When stimulating Schaffer fiber, OL displays a long duration depolarization mediated by inward rectifier potassium channel. This suggested that the OL in CA1 region could sense the neuronal activity and contribute to potassium clearance

  8. Revealing pathologies in the liquid crystalline structures of the brain by polarimetric studies (Presentation Recording)

    Science.gov (United States)

    Bakhshetyan, Karen; Melkonyan, Gurgen G.; Galstian, Tigran V.; Saghatelyan, Armen

    2015-10-01

    Natural or "self" alignment of molecular complexes in living tissue represents many similarities with liquid crystals (LC), which are anisotropic liquids. The orientational characteristics of those complexes may be related to many important functional parameters and their study may reveal important pathologies. The know-how, accumulated thanks to the study of LC materials, may thus be used to this end. One of the traditionally used methods, to characterize those materials, is the polarized light imaging (PLI) that allows for label-free analysis of anisotropic structures in the brain tissue and can be used, for example, for the analysis of myelinated fiber bundles. In the current work, we first attempted to apply the PLI on the mouse histological brain sections to create a map of anisotropic structures using cross-polarizer transmission light. Then we implemented the PLI for comparative study of histological sections of human postmortem brain samples under normal and pathological conditions, such as Parkinson's disease (PD). Imaging the coronal, sagittal and horizontal sections of mouse brain allowed us to create a false color-coded fiber orientation map under polarized light. In human brain datasets for both control and PD groups we measured the pixel intensities in myelin-rich subregions of internal capsule and normalized these to non-myelinated background signal from putamen and caudate nucleus. Quantification of intensities revealed a statistically significant reduction of fiber intensity of PD compared to control subjects (2.801 +/- 0.303 and 3.724 +/- 0.07 respectively; *p < 0.05). Our study confirms the validity of PLI method for visualizing myelinated axonal fibers. This relatively simple technique can become a promising tool for study of neurodegenerative diseases where labeling-free imaging is an important benefit.

  9. Time Slice Analysis Method Based on OTCA Used in fMRI Weak Signal Function Extraction

    Institute of Scientific and Technical Information of China (English)

    LUO Sen-lin; LI Li; ZHANG Xin-li; ZHANG Tie-mei

    2007-01-01

    The original temporal clustering analysis (OTCA) is an effective technique for obtaining brain activation maps when the timing and location of the activation are completely unknown, but its deficiency of sensitivity is exposed in processing brain activation signal which is relatively weak. The time slice analysis method based on OTCA is proposed considering the weakness of the functional magnetic resonance imaging (fMRI) signal of the rat model. By dividing the stimulation period into several time slices and analyzing each slice to detect the activated pixels respectively after the background removal, the sensitivity is significantly improved. The inhibitory response in the hypothalamus after glucose loading is detected successfully with this method in the experiment on rat. Combined with the OTCA method, the time slice analysis method based on OTCA is effective on detecting when, where and which type of response will happen after stimulation, even if the fMRI signal is weak.

  10. Development of an implantable wireless ECoG 128ch recording device for clinical brain machine interface.

    Science.gov (United States)

    Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi; Ando, Hiroshi; Ota, Yuki; Sato, Fumihiro; Morris, Shyne; Yoshida, Takeshi; Matsuki, Hidetoshi; Yoshimine, Toshiki

    2013-01-01

    Brain Machine Interface (BMI) is a system that assumes user's intention by analyzing user's brain activities and control devices with the assumed intention. It is considered as one of prospective tools to enhance paralyzed patients' quality of life. In our group, we especially focus on ECoG (electro-corti-gram)-BMI, which requires surgery to place electrodes on the cortex. We try to implant all the devices within the patient's head and abdomen and to transmit the data and power wirelessly. Our device consists of 5 parts: (1) High-density multi-electrodes with a 3D shaped sheet fitting to the individual brain surface to effectively record the ECoG signals; (2) A small circuit board with two integrated circuit chips functioning 128 [ch] analogue amplifiers and A/D converters for ECoG signals; (3) A Wifi data communication & control circuit with the target PC; (4) A non-contact power supply transmitting electrical power minimum 400[mW] to the device 20[mm] away. We developed those devices, integrated them, and, investigated the performance. PMID:24110075

  11. Development of an implantable wireless ECoG 128ch recording device for clinical brain machine interface.

    Science.gov (United States)

    Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi; Ando, Hiroshi; Ota, Yuki; Sato, Fumihiro; Morris, Shyne; Yoshida, Takeshi; Matsuki, Hidetoshi; Yoshimine, Toshiki

    2013-01-01

    Brain Machine Interface (BMI) is a system that assumes user's intention by analyzing user's brain activities and control devices with the assumed intention. It is considered as one of prospective tools to enhance paralyzed patients' quality of life. In our group, we especially focus on ECoG (electro-corti-gram)-BMI, which requires surgery to place electrodes on the cortex. We try to implant all the devices within the patient's head and abdomen and to transmit the data and power wirelessly. Our device consists of 5 parts: (1) High-density multi-electrodes with a 3D shaped sheet fitting to the individual brain surface to effectively record the ECoG signals; (2) A small circuit board with two integrated circuit chips functioning 128 [ch] analogue amplifiers and A/D converters for ECoG signals; (3) A Wifi data communication & control circuit with the target PC; (4) A non-contact power supply transmitting electrical power minimum 400[mW] to the device 20[mm] away. We developed those devices, integrated them, and, investigated the performance.

  12. Uni- and multisensory brain areas are synchronised across spectators when watching unedited dance recordings

    OpenAIRE

    Jola, Corinne; McAleer, Philip; Grosbras, Marie-Hélène; Love, Scott A.; Morison, Gordon; Pollick, Frank E.

    2013-01-01

    The superior temporal sulcus (STS) and gyrus (STG) are commonly identified to be functionally relevant for multisensory integration of audiovisual (AV) stimuli. However, most neuroimaging studies on AV integration used stimuli of short duration in explicit evaluative tasks. Importantly though, many of our AV experiences are of a long duration and ambiguous. It is unclear if the enhanced activity in audio, visual, and AV brain areas would also be synchronised over time across subjects when the...

  13. Ingot slicing machine and method

    Science.gov (United States)

    Kuo, Y. S. (Inventor)

    1984-01-01

    An improved method for simultaneously slicing one or a multiplicity of boules of silicon into silicon wafers is described. A plurality of vertical stacks of horizontal saw blades of circular configuration are arranged in juxtaposed coaxial alignment. Each blade is characterized by having a cutting diameter slightly greater than the cutting diameter of the blade arranged immediately above, imparting a simultaneous rotation to the blades.

  14. Viscous fingering of miscible slices

    CERN Document Server

    De Wit, A; Martin, M; Wit, Anne De; Bertho, Yann; Martin, Michel

    2005-01-01

    Viscous fingering of a miscible high viscosity slice of fluid displaced by a lower viscosity fluid is studied in porous media by direct numerical simulations of Darcy's law coupled to the evolution equation for the concentration of a solute controlling the viscosity of miscible solutions. In contrast with fingering between two semi-infinite regions, fingering of finite slices is a transient phenomenon due to the decrease in time of the viscosity ratio across the interface induced by fingering and dispersion processes. We show that fingering contributes transiently to the broadening of the peak in time by increasing its variance. A quantitative analysis of the asymptotic contribution of fingering to this variance is conducted as a function of the four relevant parameters of the problem i.e. the log-mobility ratio R, the length of the slice l, the Peclet number Pe and the ratio between transverse and axial dispersion coefficients $\\epsilon$. Relevance of the results is discussed in relation with transport of vi...

  15. Drying Characteristics and Product Quality of Lemon Slices Dried with Hot Air Circulation Oven and Hybrid Heatpump Dryers

    Directory of Open Access Journals (Sweden)

    Yong Hong Lee

    2014-12-01

    Full Text Available In this research, drying characteristics and product quality of Coulomb-force-assisted heatpump and oven dried lemon slices were studied. Lemon slices with 3 mm thickness each, were dried using oven and Coulomb-force-assisted-heatpump dryer with and without auxiliary heater at different drying conditions. It was found that the drying rate of the lemon slices dried by all drying methods showed only falling rate states, which indicates the drying kinetics were controlled by internal moisture diffusion. Oven drying of lemon slices at 60°C showed the highest drying rate among all, followed by oven dried slices at 50°C, Coulomb-force-heater-assisted-heatpump (CF-HT-HP dried slices at 31°C, Coulomb-force-assisted-heatpump (CF-HP dried slices at 22°C, oven dried slices at 40°C and heatpump dried slices at 22°C. The average effective moisture diffusivity value for the slices dried with these drying methods was found in the range of 16.2 to 63.8´10-4 mm2min-1. In terms of quality assessment, CF-HP dried lemon slices retained the highest amount of Vitamin C as compared to the lemon slices dried by other drying methods. However, it retained relatively lower amount of total phenolic content (TPC as compared to oven dried products. Among of all, CF-HP drying method produced dried lemon slices with the highest Vitamin C (6.74 mg AA / g dry weight whereas oven dried lemon slices at 50°C preserved most of the TPC in the dried slices, which recorded as 13.76 mg GA / g dry weight.

  16. Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

    International Nuclear Information System (INIS)

    The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [3H]dopamine and [3H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [3H]dopamine and [3H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [3H]norepinephrine or [3H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

  17. Program slicing techniques and its applications

    CERN Document Server

    Sasirekha, N; Hemalatha, Dr M

    2011-01-01

    Program understanding is an important aspect in Software Maintenance and Reengineering. Understanding the program is related to execution behaviour and relationship of variable involved in the program. The task of finding all statements in a program that directly or indirectly influence the value for an occurrence of a variable gives the set of statements that can affect the value of a variable at some point in a program is called a program slice. Program slicing is a technique for extracting parts of computer programs by tracing the programs' control and data flow related to some data item. This technique is applicable in various areas such as debugging, program comprehension and understanding, program integration, cohesion measurement, re-engineering, maintenance, testing where it is useful to be able to focus on relevant parts of large programs. This paper focuses on the various slicing techniques (not limited to) like static slicing, quasi static slicing, dynamic slicing and conditional slicing. This pape...

  18. Automatic basal slice detection for cardiac analysis

    Science.gov (United States)

    Paknezhad, Mahsa; Marchesseau, Stephanie; Brown, Michael S.

    2016-03-01

    Identification of the basal slice in cardiac imaging is a key step to measuring the ejection fraction (EF) of the left ventricle (LV). Despite research on cardiac segmentation, basal slice identification is routinely performed manually. Manual identification, however, has been shown to have high inter-observer variability, with a variation of the EF by up to 8%. Therefore, an automatic way of identifying the basal slice is still required. Prior published methods operate by automatically tracking the mitral valve points from the long-axis view of the LV. These approaches assumed that the basal slice is the first short-axis slice below the mitral valve. However, guidelines published in 2013 by the society for cardiovascular magnetic resonance indicate that the basal slice is the uppermost short-axis slice with more than 50% myocardium surrounding the blood cavity. Consequently, these existing methods are at times identifying the incorrect short-axis slice. Correct identification of the basal slice under these guidelines is challenging due to the poor image quality and blood movement during image acquisition. This paper proposes an automatic tool that focuses on the two-chamber slice to find the basal slice. To this end, an active shape model is trained to automatically segment the two-chamber view for 51 samples using the leave-one-out strategy. The basal slice was detected using temporal binary profiles created for each short-axis slice from the segmented two-chamber slice. From the 51 successfully tested samples, 92% and 84% of detection results were accurate at the end-systolic and the end-diastolic phases of the cardiac cycle, respectively.

  19. 320排全脑动态容积CT血管造影及灌注成像在烟雾病中的应用%Experience of 320-slice whole brain dynamic volume CT and perfusion imaging in patients with moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    潘宇宁; 黄求理; 叶贤旺; 张杰; 廉艳东; 傅芬芬

    2011-01-01

    Objective: To evaluate the value of 320-slice whole brain dynamic volume CT angiography and CT perfusion imaging in moyamoya disease. Methods: Eighteen cases with moyamoya disease were examined with 320-slice whole brain dynamic volume CT. Imaging data were generated with volume rendering reconstruction and display in cine mode, and complete CT perfusion imaging were performed simultaneously. Results: We succeeded in obtaining plain images of whole-brain, dynamic CTA and whole-brain perfusion images in 18 patients, all of which showed lesions of stenosis and obstruction in internal carotid artery (ICA), proximum of Willis circle and posterior and middle cerebral arteries; abnormal vessel network in the basal part of brain; and the condition of collateral circulation in the brain. Perfusion weighted imaging revealed mean transit time(MTT) was extended(0.5~13s). Ten cases showed decrease in regional cerebral blood flow(rCBF), the amplitude was 26.0%~ 54.5%. There were 8 cases of normal and 4 cases decreased in regional cerebral blood volume(rCBV). Conclusion: Whole brain dynamic volume imaging with 320-detector row CT can provide 3D structure of vessels of the whole brain, and serial of the dynamic blood flow and cerebral perfusion in a single scanning, which has the potential diagnostic value in moyamoya disease.%目的:探讨320排全脑动态容积CT血管造影及灌注成像在烟雾病中的应用价值.方法:18例烟雾病患者均行320排全脑动态容积CT扫描,并利用容积再现(VR)技术进行图像重组且采用电影模式观看,同时完成全脑灌注成像检查.结果:所有病例均获得良好的平扫容积图像、动态DSA图像及全脑灌注图像,均清晰显示发生狭窄、闭塞的颈内动脉及颅底异常血管网,其中双侧颈内动脉闭塞9例,单侧颈内动脉闭塞2例,单侧大脑中动脉闭塞7例,侧支血管表现为相应血管及其分支的粗大、增多及迂曲延长.全脑灌注图像中,显示平

  20. Fabrication and Characterization of 3D Micro- and Nanoelectrodes for Neuron Recordings

    OpenAIRE

    Romen Rodriguez-Trujillo; Indumathi Vedarethinam; Luigi Sasso; Mark Holm Olsen; Patricia Vazquez; Maria Dimaki; Winnie E. Svendsen

    2010-01-01

    In this paper we discuss the fabrication and characterization of three dimensional (3D) micro- and nanoelectrodes with the goal of using them for extra- and intracellular studies. Two different types of electrodes will be described: high aspect ratio microelectrodes for studying the communication between cells and ultimately for brain slice recordings and small nanoelectrodes for highly localized measurements and ultimately for intracellular studies. Electrical and electrochemical characteriz...

  1. Ethanol induces MAP2 changes in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Noraberg, J; Zimmer, J

    1998-01-01

    Microtubule-associated protein 2 (MAP2) and neuron-specific protein (NeuN) immunostains were used to demonstrate neurotoxic effects in mature hippocampal slice cultures exposed to ethanol (50, 100, 200 mM) for 4 weeks. At the low dose the density of MAP2 immunostaining in the dentate molecular...... layer was 118% of the control cultures, with no detectable changes in CA1 and CA3. At 100 mM no changes were detected, while 200 mM ethanol significantly reduced the MAP2 density in both dentate (19%) and hippocampal dendritic fields (CA3, 52%; CA1, 55%). At this dose NeuN staining showed considerable...... loss of CA3 pyramidal cells and moderate loss of dentate granule cells, as seen in vivo. The results indicate that brain slice cultures combined with immunostaining for cytoskeleton and neuronal markers can be used for studies of ethanol and organic solvent neurotoxicity....

  2. A silicon based implantable microelectrode array for electrophysiological and dopamine recording from cortex to striatum in the non-human primate brain.

    Science.gov (United States)

    Zhang, Song; Song, Yilin; Wang, Mixia; Zhang, Zhiming; Fan, Xinyi; Song, Xianteng; Zhuang, Ping; Yue, Feng; Chan, Piu; Cai, Xinxia

    2016-11-15

    Dual-mode, multielectrode recordings have become routine in rodent neuroscience research and have recently been adapted to the non-human primate. However, robust and reliable application of acute, multielectrode recording methods in monkeys especially for deep brain nucleus research remains a challenge. In this paper, We described a low cost silicon based 16-site implantable microelectrode array (MEA) chip fabricated by standard lithography technology for in vivo test. The array was 25mm long and designed to use in non-human primate models, for electrophysiological and electrochemical recording. We presented a detailed protocol for array fabrication, then showed that the device can record Spikes, LFPs and dopamine (DA) variation continuously from cortex to striatum in an esthetized monkey. Though our experiment, high-quality electrophysiological signals were obtained from the animal. Across any given microelectrode, spike amplitudes ranged from 70 to 300μV peak to peak, with a mean signal-to-noise ratio of better than 5:1. Calibration results showed the MEA probe had high sensitivity and good selectivity for DA. The DA concentration changed from 42.8 to 481.6μM when the MEA probe inserted from cortex into deep brain nucleus of striatum, which reflected the inhomogeneous distribution of DA in brains. Compared with existing methods allowing single mode (electrophysiology or electrochemistry) recording. This system is designed explicitly for dual-mode recording to meet the challenges of recording in non-human primates. PMID:27155116

  3. PROGRAM SLICING BASED ON INTERESTING INDEX

    Institute of Scientific and Technical Information of China (English)

    Wu Fangjun; Yi Tong

    2004-01-01

    With the scale of programs becoming increasingly bigger, and the complexity degree higher, how to select program fragments for slicing has become an important research topic. A new type of criterion called interesting index is proposed for selecting parts of procedures or procedure fragments to do program slicing. This new criterion considers not only the subjective aspects in users, namely users' emphasis on the time efficiency, storage capacity or readability,but also the objective aspect in large procedures. It also represents the benefit of the users, while displaying the many-faceted roles that program slicing plays. In this way users can proceed with program slicing to large systems or unfinished systems.

  4. Cell-attached recordings of responses evoked by photorelease of GABA in the immature cortical neurons

    OpenAIRE

    Marat eMinlebaev; Guzel eValeeva; Vadim eTcheremiskine; Gaelle eCoustillier; Rustem eKhazipov

    2013-01-01

    We present a novel non-invasive technique to measure the polarity of GABAergic responses based on cell-attached recordings of currents activated by laser-uncaging of GABA. For these recordings, a patch pipette was filled with a solution containing RuBi-GABA, and GABA was released from this complex by a laser beam conducted to the tip of the patch pipette via an optic fiber. In cell-attached recordings from neocortical and hippocampal neurons in postnatal days P2-5 rat brain slices in vitro, w...

  5. Brain injury impairs working memory and prefrontal circuit function

    Directory of Open Access Journals (Sweden)

    Colin James Smith

    2015-11-01

    Full Text Available More than 2.5 million Americans suffer a traumatic brain injury (TBI each year. Even mild to moderate traumatic brain injury causes long-lasting neurological effects. Despite its prevalence, no therapy currently exists to treat the underlying cause of cognitive impairment suffered by TBI patients. Following lateral fluid percussion injury (LFPI, the most widely used experimental model of TBI, we investigated alterations in working memory and excitatory/inhibitory synaptic balance in the prefrontal cortex. LFPI impaired working memory as assessed with a T-maze behavioral task. Field excitatory postsynaptic potentials recorded in the prefrontal cortex were reduced in slices derived from brain-injured mice. Spontaneous and miniature excitatory postsynaptic currents onto layer 2/3 neurons were more frequent in slices derived from LFPI mice while inhibitory currents onto layer 2/3 neurons were smaller after LFPI. Additionally, an increase in action potential threshold and concomitant decrease in firing rate was observed in layer 2/3 neurons in slices from injured animals. Conversely, no differences in excitatory or inhibitory synaptic transmission onto layer 5 neurons were observed; however, layer 5 neurons demonstrated a decrease in input resistance and action potential duration after LFPI. These results demonstrate synaptic and intrinsic alterations in prefrontal circuitry that may underlie working memory impairment caused by TBI.

  6. Integrating interface slicing into software engineering processes

    Science.gov (United States)

    Beck, Jon

    1993-01-01

    Interface slicing is a tool which was developed to facilitate software engineering. As previously presented, it was described in terms of its techniques and mechanisms. The integration of interface slicing into specific software engineering activities is considered by discussing a number of potential applications of interface slicing. The applications discussed specifically address the problems, issues, or concerns raised in a previous project. Because a complete interface slicer is still under development, these applications must be phrased in future tenses. Nonetheless, the interface slicing techniques which were presented can be implemented using current compiler and static analysis technology. Whether implemented as a standalone tool or as a module in an integrated development or reverse engineering environment, they require analysis no more complex than that required for current system development environments. By contrast, conventional slicing is a methodology which, while showing much promise and intuitive appeal, has yet to be fully implemented in a production language environment despite 12 years of development.

  7. Physiological Effects of Enriched Environment Exposure and LTP Induction in the Hippocampus In Vivo Do Not Transfer Faithfully to In Vitro Slices

    Science.gov (United States)

    Eckert, Michael J.; Abraham, Wickliffe C.

    2010-01-01

    A number of experimental paradigms use in vitro brain slices to test for changes in synaptic transmission and plasticity following a behavioral manipulation. For example, a number of previous studies have reported a variety of effects of environmental enrichment (EE) exposure on field potential responses in hippocampal slices, but in no study was…

  8. 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

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

    Science.gov (United States)

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

    2011-05-01

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

  10. Radiation sterilization and identification of gizzard slices

    International Nuclear Information System (INIS)

    An orthogonal test of γ-radiation, storage temperature and time before irradiation, and the sanitation for cutting was carried out on gizzard slices. The test conditions were practicable for food irradiation processing. To identify irradiated gizzard slices, sensory changes, water-soluble nitrogen, amino acids, total volatile basic nitrogen (TVBN), peroxide value (POV), vitamin C consumption and KMnO4 consumption were detected, no significant changes were observed except the color which was light brown on the surface. Both the sanitary quality and the shelf-life of gizzard slices were improved by irradiation

  11. The ATLAS Trigger Muon "Vertical Slice"

    CERN Document Server

    Sidoti, A; Biglietti, M; Carlino, G; Cataldi, G; Conventi, F; Del Prete, T; Di Mattia, A; Falciano, S; Gorini, S; Kanaya, N; Kohno, T; Krasznahorkay, A; Lagouri, T; Luci, C; Luminari, L; Marzano, F; Nagano, K; Nisati, A; Panikashvili, N; Pasqualucci, E; Primavera, M; Scannicchio, D A; Spagnolo, S; Tarem, S; Tarem, Z; Tokushuku, K; Usai, G; Ventura, A; Vercesi, V; Yamazaki, Y; 10th Pisa Meeting on Advanced Detectors : Frontier Detectors For Frontier Physics

    2007-01-01

    The muon trigger system is a fundamental component of the ATLAS detector at the LHC collider. In this paper we describe the ATLAS multi-level trigger selecting events with muons: the Muon Trigger Slice.

  12. Coordinate Singularities in Harmonically-sliced Cosmologies

    CERN Document Server

    Hern, S D

    2000-01-01

    Harmonic slicing has in recent years become a standard way of prescribing the lapse function in numerical simulations of general relativity. However, as was first noticed by Alcubierre (1997), numerical solutions generated using this slicing condition can show pathological behaviour. In this paper, analytic and numerical methods are used to examine harmonic slicings of Kasner and Gowdy cosmological spacetimes. It is shown that in general the slicings are prevented from covering the whole of the spacetimes by the appearance of coordinate singularities. As well as limiting the maximum running times of numerical simulations, the coordinate singularities can lead to features being produced in numerically evolved solutions which must be distinguished from genuine physical effects.

  13. GDNF and neublastin protect against NMDA-induced excitotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Bonde, C; Kristensen, B W; Blaabjerg, M;

    2000-01-01

    The potential neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) and neublastin (NBN) against NMDA-induced excitotoxicity were examined in hippocampal brain slice cultures. Recombinant human GDNF (25-100 ng/ ml) or NBN, in medium conditioned by growth of transfected, NBN......-producing HiB5 cells, were added to slice cultures I h before exposure to 10 microM NMDA for 48h. Neuronal cell death was monitored, before and during the NMDA exposure, by densitometric measurements of propidium iodide (PI) uptake and loss of Nissl staining. Both the addition of rhGDNF and NBN...

  14. Slicing Strategy for Selective Laser Melting

    Institute of Scientific and Technical Information of China (English)

    SONG Xin; LIU Ji-quan; FAN Shu-qian

    2014-01-01

    Selective laser melting (SLM) is one of the most popular additive manufacturing (AM) technologies for metal parts. Slicing result, especially for the different dimensional slicing geometry and its topology, plays an important role because of the thermodynamic behavior of metal powders. To get correct geometry and reliable topology, a slicing strategy for SLM is proposed. The unavoidable numerical error caused by sampling and geometric transformation is suppressed firstly, according to shifting the z-coordinate of a vertex with a small value such the shifted vertex is on a slicing plane. The result of vertex-shifting makes it possible to identify different geometric features such as skin surfaces, overhang surfaces, extreme edges and volumetric solid. Second, from geometric primitives a hierarchy of axis-aligned bounding boxes (AABBs) is constructed and used to speed up intersection of slicing planes against sets of triangles. All intersecting segments are given different signs to depict their geometric or topological information. Based the different signs, the different dimensional geometry that is eventually represented by simple and anticlockwise oriented polygons, are identified. Finally, the polygons are classified and nested in a multi-tree data structure set to produce correct topological relations. The result of digital and physical experiments shows the proposed slicing strategy is feasible and robust.

  15. Fluoride Induces a Volume Reduction in CA1 Hippocampal Slices Via MAP Kinase Pathway Through Volume Regulated Anion Channels.

    Science.gov (United States)

    Lee, Jaekwang; Han, Young-Eun; Favorov, Oleg; Tommerdahl, Mark; Whitsel, Barry; Lee, C Justin

    2016-04-01

    Regulation of cell volume is an important aspect of cellular homeostasis during neural activity. This volume regulation is thought to be mediated by activation of specific transporters, aquaporin, and volume regulated anion channels (VRAC). In cultured astrocytes, it was reported that swelling-induced mitogen-activated protein (MAP) kinase activation is required to open VRAC, which are thought to be important in regulatory volume decrease and in the response of CNS to trauma and excitotoxicity. It has been also described that sodium fluoride (NaF), a recognized G-protein activator and protein phosphatase inhibitor, leads to a significant MAP kinase activation in endothelial cells. However, NaF's effect in volume regulation in the brain is not known yet. Here, we investigated the mechanism of NaF-induced volume change in rat and mouse hippocampal slices using intrinsic optical signal (IOS) recording, in which we measured relative changes in intracellular and extracellular volume as changes in light transmittance through brain slices. We found that NaF (1~5 mM) application induced a reduction in light transmittance (decreased volume) in CA1 hippocampus, which was completely reversed by MAP kinase inhibitor U0126 (10 µM). We also observed that NaF-induced volume reduction was blocked by anion channel blockers, suggesting that NaF-induced volume reduction could be mediated by VRAC. Overall, our results propose a novel molecular mechanism of NaF-induced volume reduction via MAP kinase signaling pathway by activation of VRAC. PMID:27122993

  16. Fluoride Induces a Volume Reduction in CA1 Hippocampal Slices Via MAP Kinase Pathway Through Volume Regulated Anion Channels

    Science.gov (United States)

    Lee, Jaekwang; Han, Young-Eun; Favorov, Oleg; Tommerdahl, Mark; Whitsel, Barry

    2016-01-01

    Regulation of cell volume is an important aspect of cellular homeostasis during neural activity. This volume regulation is thought to be mediated by activation of specific transporters, aquaporin, and volume regulated anion channels (VRAC). In cultured astrocytes, it was reported that swelling-induced mitogen-activated protein (MAP) kinase activation is required to open VRAC, which are thought to be important in regulatory volume decrease and in the response of CNS to trauma and excitotoxicity. It has been also described that sodium fluoride (NaF), a recognized G-protein activator and protein phosphatase inhibitor, leads to a significant MAP kinase activation in endothelial cells. However, NaF's effect in volume regulation in the brain is not known yet. Here, we investigated the mechanism of NaF-induced volume change in rat and mouse hippocampal slices using intrinsic optical signal (IOS) recording, in which we measured relative changes in intracellular and extracellular volume as changes in light transmittance through brain slices. We found that NaF (1~5 mM) application induced a reduction in light transmittance (decreased volume) in CA1 hippocampus, which was completely reversed by MAP kinase inhibitor U0126 (10 µM). We also observed that NaF-induced volume reduction was blocked by anion channel blockers, suggesting that NaF-induced volume reduction could be mediated by VRAC. Overall, our results propose a novel molecular mechanism of NaF-induced volume reduction via MAP kinase signaling pathway by activation of VRAC. PMID:27122993

  17. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta

    OpenAIRE

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2015-01-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient’s age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases. Brain bleeding volume i...

  18. 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

  19. Mechanisms contributing to cluster formation in the inferior olivary nucleus in brainstem slices from postnatal mice

    DEFF Research Database (Denmark)

    Kølvraa, Mathias; Müller, Felix C; Jahnsen, Henrik;

    2014-01-01

    The inferior olivary nucleus (IO) in in vitro slices from postnatal mice (P5.5-P15.5) spontaneously generates clusters of neurons with synchronous calcium transients, and intracellular recordings from IO neurons suggest that electrical coupling between neighbouring IO neurons may serve as a synch...

  20. Source-based neurofeedback methods using EEG recordings: training altered brain activity in a functional brain source derived from blind source separation

    OpenAIRE

    David James White; Marco eCongedo; Joseph eCiorciari

    2014-01-01

    International audience A developing literature explores the use of neurofeedback in the treatment of a range of clinical conditions, particularly ADHD and epilepsy, whilst neurofeedback also provides an experimental tool for studying the functional significance of endogenous brain activity. A critical component of any neurofeedback method is the underlying physiological signal which forms the basis for the feedback. While the past decade has seen the emergence of fMRI-based protocols train...

  1. Whole-body diffusion imaging applying simultaneous multi-slice excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kenkel, David; Wurning, M.C.; Filli, L.; Ulbrich, E.J.; Boss, A. [Universitaetsspital Zuerich (Switzerland). Diagnostische und Interventionelle Radiologie; Runge, V.M. [Univ. Hospital Zurich (Switzerland). Dept. of Neuroradiology; Beck, T. [Siemens Healthcare GmbH, Erlangen (Germany)

    2016-04-15

    The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol. A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3 T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale. Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9 %. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol. It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability.

  2. Staining protocol for organotypic hippocampal slice cultures.

    Science.gov (United States)

    Gogolla, Nadine; Galimberti, Ivan; DePaola, Vincenzo; Caroni, Pico

    2006-01-01

    This protocol details a method to immunostain organotypic slice cultures from mouse hippocampus. The cultures are based on the interface method, which does not require special equipment, is easy to execute and yields slice cultures that can be imaged repeatedly, from the time of isolation at postnatal day 6-9 up to 6 months in vitro. The preserved tissue architecture facilitates the analysis of defined hippocampal synapses, cells and entire projections. Time-lapse imaging is based on transgenes expressed in the mice or on constructs introduced through transfection or viral vectors; it can reveal processes that develop over periods ranging from seconds to months. Subsequent to imaging, the slices can be processed for immunocytochemistry to collect further information about the imaged structures. This protocol can be completed in 3 d.

  3. Dynamic Backward Slicing of Rewriting Logic Computations

    CERN Document Server

    Alpuente, María; Espert, Javier; Romero, Daniel

    2011-01-01

    Trace slicing is a widely used technique for execution trace analysis that is effectively used in program debugging, analysis and comprehension. In this paper, we present a backward trace slicing technique that can be used for the analysis of Rewriting Logic theories. Our trace slicing technique allows us to systematically trace back rewrite sequences modulo equational axioms (such as associativity and commutativity) by means of an algorithm that dynamically simplifies the traces by detecting control and data dependencies, and dropping useless data that do not influence the final result. Our methodology is particularly suitable for analyzing complex, textually-large system computations such as those delivered as counter-example traces by Maude model-checkers.

  4. Interactive Slice of the CMS detector

    CERN Document Server

    Davis, Siona Ruth

    2016-01-01

    This slice shows a colorful cross-section of the CMS detector with all parts of the detector labelled. Viewers are invited to click on buttons associated with five types of particles to see what happens when each type interacts with the sections of the detector. The five types of particles users can select to send through the slice are muons, electrons, neutral hadrons, charged hadrons and photons. Supplementary information on each type of particles is given. Useful for inclusion into general talks on CMS etc. *Animated CMS "slice" for Powerpoint (Mac & PC) Original version - 2004 Updated version - July 2010 *Six slides required - first is a set of buttons; others are for each particle type (muon, electron, charged/neutral hadron, photon) Recommend putting slide 1 anywhere in your presentation and the rest at the end

  5. Dynamic Slicing of Object-Oriented Programs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Program slice has many applications such as program debugging,testing, maintena n ce, and complexity measurement. A static slice consists of all statements in pro gram P that may effect the value of variable v at some point p, and a dynamic s lice consists only of statements that influence the value of variable occurrence for specific program inputs. In this paper, we concern the problem of dynamic s licing of object-oriented programs which, to our knowledge, has not been addres s ed in the literatures. To solve this problem, we present the dynamic object-ori e nted dependence graph (DODG)which is an arc-classified digraph to explicitly re p resent various dynamic dependence between statement instances for a particular e xecution of an object-oriented program. Based on the DODG, we present a two-ph as e backward algorithm for computing a dynamic slice of an object-oriented program.

  6. In Vitro Manganese Exposure Disrupts MAPK Signaling Pathways in Striatal and Hippocampal Slices from Immature Rats

    Directory of Open Access Journals (Sweden)

    Tanara Vieira Peres

    2013-01-01

    Full Text Available The molecular mechanisms mediating manganese (Mn-induced neurotoxicity, particularly in the immature central nervous system, have yet to be completely understood. In this study, we investigated whether mitogen-activated protein kinases (MAPKs and tyrosine hydroxylase (TH could represent potential targets of Mn in striatal and hippocampal slices obtained from immature rats (14 days old. The aim of this study was to evaluate if the MAPK pathways are modulated after subtoxic Mn exposure, which do not significantly affect cell viability. The concentrations of manganese chloride (MnCl2; 10–1,000 μM caused no change in cell viability in slices exposed for 3 or 6 hours. However, Mn exposure significantly increased extracellular signal-regulated kinase (ERK 1/2, as well as c-Jun N-terminal kinase (JNK 1/2/3 phosphorylation at both 3 and 6 hours incubations, in both brain structures. Furthermore, Mn exposure did not change the total content or phosphorylation of TH at the serine 40 site in striatal slices. Thus, Mn at concentrations that do not disrupt cell viability causes activation of MAPKs (ERK1/2 and JNK1/2/3 in immature hippocampal and striatal slices. These findings suggest that altered intracellular MAPKs signaling pathways may represent an early event concerning the effects of Mn in the immature brain.

  7. In Vitro Manganese Exposure Disrupts MAPK Signaling Pathways in Striatal and Hippocampal Slices from Immature Rats

    Science.gov (United States)

    Peres, Tanara Vieira; Pedro, Daniela Zótico; de Cordova, Fabiano Mendes; Lopes, Mark William; Gonçalves, Filipe Marques; Mendes-de-Aguiar, Cláudia Beatriz Nedel; Walz, Roger; Farina, Marcelo; Aschner, Michael; Leal, Rodrigo Bainy

    2013-01-01

    The molecular mechanisms mediating manganese (Mn)-induced neurotoxicity, particularly in the immature central nervous system, have yet to be completely understood. In this study, we investigated whether mitogen-activated protein kinases (MAPKs) and tyrosine hydroxylase (TH) could represent potential targets of Mn in striatal and hippocampal slices obtained from immature rats (14 days old). The aim of this study was to evaluate if the MAPK pathways are modulated after subtoxic Mn exposure, which do not significantly affect cell viability. The concentrations of manganese chloride (MnCl2; 10–1,000 μM) caused no change in cell viability in slices exposed for 3 or 6 hours. However, Mn exposure significantly increased extracellular signal-regulated kinase (ERK) 1/2, as well as c-Jun N-terminal kinase (JNK) 1/2/3 phosphorylation at both 3 and 6 hours incubations, in both brain structures. Furthermore, Mn exposure did not change the total content or phosphorylation of TH at the serine 40 site in striatal slices. Thus, Mn at concentrations that do not disrupt cell viability causes activation of MAPKs (ERK1/2 and JNK1/2/3) in immature hippocampal and striatal slices. These findings suggest that altered intracellular MAPKs signaling pathways may represent an early event concerning the effects of Mn in the immature brain. PMID:24324973

  8. Ultrashort pulse laser slicing of semiconductor crystal

    Science.gov (United States)

    Kim, Eunho; Shimotsuma, Yasuhiko; Sakakura, Masaaki; Miura, Kiyotaka

    2016-07-01

    Meanwhile, by the convention wire-saw technique, it is difficult to slice off a thin wafer from bulk SiC crystal without the reserving space for cutting. In this study, we have achieved exfoliation of 4H-SiC single crystal by femtosecond laser induced slicing method. By using this, the exfoliated surface with the root-mean-square roughness of 3 μm and the cutting-loss thickness smaller than 30 μm was successfully demonstrated. We have also observed the nanostructure on the exfoliated surface in SiC crystal.

  9. Effects of Temperature and Slice Thickness on Drying Kinetics of Pumpkin Slices

    OpenAIRE

    Kongdej LIMPAIBOON

    2011-01-01

    Dried pumpkin slice is an alternative crisp food product. In this study, the effects of temperature and slice thickness on the drying characteristics of pumpkin were studied in a lab-scale tray dryer, using hot air temperatures of 55, 60 and 65 °C and 2, 3 and 4 mm slice thickness at a constant air velocity of 1.5 m/s. The initial moisture content of the pumpkin samples was 900.5 % (wb). The drying process was carried out until the final moisture content of product was 100.5 % (wb). The resul...

  10. Detecting Psychopathy from Thin Slices of Behavior

    Science.gov (United States)

    Fowler, Katherine A.; Lilienfeld, Scott O.; Patrick, Christopher J.

    2009-01-01

    This study is the first to demonstrate that features of psychopathy can be reliably and validly detected by lay raters from "thin slices" (i.e., small samples) of behavior. Brief excerpts (5 s, 10 s, and 20 s) from interviews with 96 maximum-security inmates were presented in video or audio form or in both modalities combined. Forty raters used…

  11. Thin-Slice Perception Develops Slowly

    Science.gov (United States)

    Balas, Benjamin; Kanwisher, Nancy; Saxe, Rebecca

    2012-01-01

    Body language and facial gesture provide sufficient visual information to support high-level social inferences from "thin slices" of behavior. Given short movies of nonverbal behavior, adults make reliable judgments in a large number of tasks. Here we find that the high precision of adults' nonverbal social perception depends on the slow…

  12. 5-azacytidine and purine nucleotide synthesis in guinea-pig cerebral cortex slices by salvage pathway from adenine

    International Nuclear Information System (INIS)

    The effect of the cytostatic, immunosuppressive and antiviral drug 5-azacytidine was studied on the synthesis of purine nucleotides and the total RNA fraction by the salvage pathway of adenine in in vitro experiments on slices from the brain cortex while the azapyrimidine nucleoside only decreased the specific radioactivity of nucleotide adenine and quanine in a relatively high resulting concentration (10-2M), no differences were found between the slices of the brain cortex incubated with and without 5-azacytidine. The comparison of the specific radioactivities of adenine of the total RNA fraction gave a similar picture. No substantial differences were observed between the levels of adenine nucleotides and the total RNA fraction in slices incubated with and without 5-azacytidine. (author)

  13. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta.

    Science.gov (United States)

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2016-04-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient's age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases.  Brain bleeding volume is the dependent variable, obtained through slice thickness of 5 mm and ABC/2 method with software measurement in MSCT Scan device. The independent variable of this study is the patient's age. The result of the study was the average brain's bleeding volume of 21.76 ml ± 2.48 ml (range of 1.04 ml to 94.73 ml).The slice thickness using ABC/2 method, has a significant correlation with brain's bleeding volume in MSCT Scan examination, with correlation coefficient value r of 0.79. Brain bleeding volume in patients who have ages lower than 50 years and more or equal to 50 years were (18.93 ± 3.26) ml and (23.53 ± 3.47) ml respectively. There is no correlation between age and brain's bleeding volume in haemorrhagic stroke cases, with p value of 0.18, r = 0.19. PMID:26573030

  14. Extremely-low-frequency magnetic fields disrupt rhythmic slow activity in rat hippocampal slices.

    Science.gov (United States)

    Bawin, S M; Satmary, W M; Jones, R A; Adey, W R; Zimmerman, G

    1996-01-01

    Several studies have indicated that weak, extremely-low-frequency (ELF; 1-100 Hz) magnetic fields affect brain electrical activity and memory processes in man and laboratory animals. Our studies sought to determine whether ELF magnetic fields could couple directly with brain tissue and affect neuronal activity in vitro. We used rat hippocampal slices to study field effects on a specific brain activity known as rhythmic slow activity (RSA), or theta rhythm, which occurs in 7-15 s bursts in the hippocampus during memory functions. RSA, which, in vivo, is a cholinergic activity, is induced in hippocampal slices by perfusion of the tissue with carbachol, a stable analog of acetylcholine. We previously demonstrated that the free radical nitric oxide (NO), synthesized in carbachol-treated hippocampal slices, lengthened and destabilized the intervals between successive RSA episodes. Here, we investigate the possibility that sinusoidal ELF magnetic fields could trigger the NO-dependent perturbation of the rate of occurrence of the RSA episodes. Carbachol-treated slices were exposed for 10 min epochs to 1 or 60 Hz magnetic fields with field intensities of 5.6, 56, or 560 microT (rms), or they were sham exposed. All exposures took place in the presence of an ambient DC field of 45 microT, with an angle of -66 degrees from the horizontal plane. Sinusoidal 1 Hz fields at 56 and 560 microT, but not at 5.6 microT, triggered the irreversible destabilization of RSA intervals. Fields at 60 Hz resulted in similar, but not statistically significant, trends. Fields had no effects on RSA when NO synthesis was pharmacologically inhibited. However, field effects could take place when extracellular NO, diffusing from its cell of origin to the extracellular space,was chelated by hemoglobin. These results suggest that ELF magnetic fields exert a strong influence on NO systems in the brain; therefore, they could modulate the functional state of a variety of neuronal ensembles. PMID:8915548

  15. Localized gene transfer into organotypic hippocampal slice cultures and acute hippocampal slices

    DEFF Research Database (Denmark)

    Casaccia-Bonnefil, P; Benedikz, Eirikur; Shen, H;

    1993-01-01

    Viral vectors derived from herpes simplex virus, type-1 (HSV), can transfer and express genes into fully differentiated, post-mitotic neurons. These vectors also transduce cells effectively in organotypic hippocampal slice cultures. Nanoliter quantities of a virus stock of HSVlac, an HSV vector...... effective and rapid. The titer of the HSVlac stocks was determined on NIH3T3 cells. Eighty-three percent of the beta-gal forming units successfully transduced beta-gal after microapplication to slice cultures. beta-Gal expression was detected as rapidly as 4 h after transduction into cultures of fibroblasts...... or hippocampal slices. The rapid expression of beta-gal by HSVlac allowed efficient transduction of acute hippocampal slices. Many genes have been transduced and expressed using HSV vectors; therefore, this microapplication method can be applied to many neurobiological questions....

  16. Dynamics of regional brain activity in epilepsy: a cross-disciplinary study on both intracranial and scalp-recorded epileptic seizures

    Science.gov (United States)

    Minadakis, George; Ventouras, Errikos; Gatzonis, Stylianos D.; Siatouni, Anna; Tsekou, Hara; Kalatzis, Ioannis; Sakas, Damianos E.; Stonham, John

    2014-04-01

    Objective. Recent cross-disciplinary literature suggests a dynamical analogy between earthquakes and epileptic seizures. This study extends the focus of inquiry for the applicability of models for earthquake dynamics to examine both scalp-recorded and intracranial electroencephalogram recordings related to epileptic seizures. Approach. First, we provide an updated definition of the electric event in terms of magnitude and we focus on the applicability of (i) a model for earthquake dynamics, rooted in a nonextensive Tsallis framework, (ii) the traditional Gutenberg and Richter law and (iii) an alternative method for the magnitude-frequency relation for earthquakes. Second, we apply spatiotemporal analysis in terms of nonextensive statistical physics and we further examine the behavior of the parameters included in the nonextensive formula for both types of electroencephalogram recordings under study. Main results. We confirm the previously observed power-law distribution, showing that the nonextensive formula can adequately describe the sequences of electric events included in both types of electroencephalogram recordings. We also show the intermittent behavior of the epileptic seizure cycle which is analogous to the earthquake cycles and we provide evidence of self-affinity of the regional electroencephalogram epileptic seizure activity. Significance. This study may provide a framework for the analysis and interpretation of epileptic brain activity and other biological phenomena with similar underlying dynamical mechanisms.

  17. Role of adenosine in the antiepileptic effects of deep brain stimulation

    Science.gov (United States)

    Miranda, Maisa F.; Hamani, Clement; de Almeida, Antônio-Carlos G.; Amorim, Beatriz O.; Macedo, Carlos E.; Fernandes, Maria José S.; Nobrega, José N.; Aarão, Mayra C.; Madureira, Ana Paula; Rodrigues, Antônio M.; Andersen, Monica L.; Tufik, Sergio; Mello, Luiz E.; Covolan, Luciene

    2014-01-01

    Despite the effectiveness of anterior thalamic nucleus (AN) deep brain stimulation (DBS) for the treatment of epilepsy, mechanisms responsible for the antiepileptic effects of this therapy remain elusive. As adenosine modulates neuronal excitability and seizure activity in animal models, we hypothesized that this nucleoside could be one of the substrates involved in the effects of AN DBS. We applied 5 days of stimulation to rats rendered chronically epileptic by pilocarpine injections and recorded epileptiform activity in hippocampal slices. We found that slices from animals given DBS had reduced hippocampal excitability and were less susceptible to develop ictal activity. In live animals, AN DBS significantly increased adenosine levels in the hippocampus as measured by microdialysis. The reduced excitability of DBS in vitro was completely abolished in animals pre-treated with A1 receptor antagonists and was strongly potentiated by A1 receptor agonists. We conclude that some of the antiepileptic effects of DBS may be mediated by adenosine. PMID:25324724

  18. Optogenetic Evocation of Field Inhibitory Postsynaptic Potentials in Hippocampal Slices: A Simple and Reliable Approach for Studying Pharmacological Effects on GABAA and GABAB Receptor-Mediated Neurotransmission

    Directory of Open Access Journals (Sweden)

    Julien eDine

    2014-01-01

    Full Text Available The GABAergic system is the main source of inhibition in the mammalian brain. Consequently, much effort is still made to develop new modulators of GABAergic synaptic transmission. In contrast to glutamatergic postsynaptic potentials (PSPs, accurate monitoring of GABA receptor-mediated PSPs (GABAR-PSPs and their pharmacological modulation in brain tissue invariably requires the use of intracellular recording techniques. However, these techniques are expensive, time- and labor-consuming, and, in case of the frequently employed whole-cell patch-clamp configuration, impact on intracellular ion concentrations, signaling cascades, and pH buffering systems. Here, we describe a novel approach to circumvent these drawbacks. In particular, we demonstrate in mouse hippocampal slices that selective optogenetic activation of interneurons leads to prominent field inhibitory GABAAR- and GABABR-PSPs in area CA1 which are easily and reliably detectable by a single extracellular recording electrode. The field PSPs exhibit typical temporal and pharmacological characteristics, display pronounced paired-pulse depression, and remain stable over many consecutive evocations. Additionally validating the methodological value of this approach, we further show that the neuroactive steroid 5-THDOC (5 µM shifts the inhibitory GABAAR-PSPs towards excitatory ones.

  19. slice of a LEP bending magnet

    CERN Multimedia

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  20. Slice of a LEP bending magnet

    CERN Multimedia

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich. The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  1. 05451 Abstracts Collection -- Beyond Program Slicing

    OpenAIRE

    Binkley, Dave; Harman, Mark; Krinke, Jens

    2006-01-01

    From 06.11.05 to 11.11.05, the Dagstuhl Seminar 05451 ``Beyond Program Slicing'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics ...

  2. TRANSFORM DOMAIN SLICE BASED DISTRIBUTED VIDEO CODING

    OpenAIRE

    SAMIR BELHOUARI; VARUN JEOTI; A. ELAMIN

    2011-01-01

    Distributed video coding depends heavily on the virtual channel model. Due to the limitations of the side information estimation one stationary model does not properly describe the virtual channel. In this work the correlation noise is modelled per slice to obtain location-specific correlation noise model. The resulting delay from the lengthy Slepian-Wolf (SW) codec input is also reduced by reducing the length of SW codec input. The proposed solution does not impose any extra complexity, it u...

  3. Fabrication and Characterization of 3D Micro- and Nanoelectrodes for Neuron Recordings

    DEFF Research Database (Denmark)

    Dimaki, Maria; Vazquez, Patricia; Olsen, Mark Holm;

    2010-01-01

    In this paper we discuss the fabrication and characterization of three dimensional (3D) micro- and nanoelectrodes with the goal of using them for extra- and intracellular studies. Two different types of electrodes will be described: high aspect ratio microelectrodes for studying the communication...... between cells and ultimately for brain slice recordings and small nanoelectrodes for highly localized measurements and ultimately for intracellular studies. Electrical and electrochemical characterization of these electrodes as well as the results of PC12 cell differentiation on chip will be presented...

  4. Additional value of two-channel amplitude integrated EEG recording in full-term infants with unilateral brain injury

    NARCIS (Netherlands)

    van Rooij, Linda G. M.; de Vries, Linda S.; van Huffelen, Alexander C.; Toet, Mona C.

    2010-01-01

    Background Amplitude integrated electroencephalography (aEEG) is a valuable tool for evaluating neonatal encephalopathy and identifying electrographic seizures. Objective To compare seizure activity and background pattern (BGP) between one-channel and two-channel aEEG recordings in full-term neonate

  5. Application of Dynamic Slicing in Test Data Generation

    Institute of Scientific and Technical Information of China (English)

    QUO Suwei; ZHAO Ruilian; LI Lijian

    2007-01-01

    The program slicing technique is employed to calculate the current values of the variables at some interest points in software test data generation. This paper introduces the concept of statement domination to represent the multiple nests, and presents a dynamic program slice algorithm based on forward analysis to generate dynamic slices. In the approach, more attention is given to the statement itself or its domination node, so computing program slices is more easy and accurate, especially for those programs with multiple nests. In addition, a case study is discussed to illustrate our algorithm. Experimental results show that the slicing technique can be used in software test data generation to enhance the effectiveness.

  6. A Review of Variable Slicing in Fused Deposition Modeling

    Science.gov (United States)

    Nadiyapara, Hitesh Hirjibhai; Pande, Sarang

    2016-06-01

    The paper presents a literature survey in the field of fused deposition of plastic wires especially in the field of slicing and deposition using extrusion of thermoplastic wires. Various researchers working in the field of computation of deposition path have used their algorithms for variable slicing. In the study, a flowchart has also been proposed for the slicing and deposition process. The algorithm already been developed by previous researcher will be used to be implemented on the fused deposition modelling machine. To demonstrate the capabilities of the fused deposition modeling machine a case study has been taken. It uses a manipulated G-code to be fed to the fused deposition modeling machine. Two types of slicing strategies, namely uniform slicing and variable slicing have been evaluated. In the uniform slicing, the slice thickness has been used for deposition is varying from 0.1 to 0.4 mm. In the variable slicing, thickness has been varied from 0.1 in the polar region to 0.4 in the equatorial region Time required and the number of slices required to deposit a hemisphere of 20 mm diameter have been compared with that using the variable slicing.

  7. Rapid method for fetal brain fixation.

    OpenAIRE

    Nicholls, J. M.

    1988-01-01

    A quicker alternative to the standard removal and fixation of brain tissue was sought. Whole fetal brains were fixed in situ using a mercuric based fixative. The subarachnoid space was perfused overnight with Heidenhain's Susa fixative. The following day the brains were removed from the cranium in the standard manner. After storage for three days in Susa's fixative the brain was sliced and processed, with excellent preservation of gross and microscopic architecture. The cost is only marginall...

  8. Controlling selective stimulations below a spinal cord hemisection using brain recordings with a neural interface system approach

    Science.gov (United States)

    Panetsos, Fivos; Sanchez-Jimenez, Abel; Torets, Carlos; Largo, Carla; Micera, Silvestro

    2011-08-01

    In this work we address the use of realtime cortical recordings for the generation of coherent, reliable and robust motor activity in spinal-lesioned animals through selective intraspinal microstimulation (ISMS). The spinal cord of adult rats was hemisectioned and groups of multielectrodes were implanted in both the central nervous system (CNS) and the spinal cord below the lesion level to establish a neural system interface (NSI). To test the reliability of this new NSI connection, highly repeatable neural responses recorded from the CNS were used as a pattern generator of an open-loop control strategy for selective ISMS of the spinal motoneurons. Our experimental procedure avoided the spontaneous non-controlled and non-repeatable neural activity that could have generated spurious ISMS and the consequent undesired muscle contractions. Combinations of complex CNS patterns generated precisely coordinated, reliable and robust motor actions.

  9. Development of DARPP-32-positive parts of fetal pig ganglionic eminence and ventral mesencephalon in organotypic slice co-cultures

    DEFF Research Database (Denmark)

    Dall, Annette Møller; Rasmussen, Jens Zimmer

    2006-01-01

    Neurons from the fetal pig dopaminergic ventral mesencephalon (VM) and basal ganglia anlage (the ganglionic eminence) were co-cultured as organotypic slice cultures to study the development of the two interconnected brain areas. During a short developmental period (E35-E42), a groove separates...... (TH)-positive, dopaminergic fibers from co-cultured slices of the ventral mesencephalon. DARPP-32 expression was more extensive and dense in cultures of the lateral part of the striatal anlage than the medial part. The DARPP-32-positive areas moreover overlapped with areas rich in acetylcholine...

  10. Cannabinoids Occlude the HIV-1 Tat-Induced Decrease in GABAergic Neurotransmission in Prefrontal Cortex Slices.

    Science.gov (United States)

    Xu, Changqing; Hermes, Douglas J; Mackie, Ken; Lichtman, Aron H; Ignatowska-Jankowska, Bogna M; Fitting, Sylvia

    2016-06-01

    In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is now considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND). Endocannabinoids exhibit neuroprotective and anti-inflammatory properties in several central nervous system (CNS) disease models, but their effects in HAND are poorly understood. To address this issue, whole-cell recordings were performed on young (14-24 day old) C57BL/6J mice. We investigated the actions of the synthetic cannabinoid WIN55,212-2 (1 μM) and the endocannabinoid N-arachidonoyl ethanolamine (anandamide; AEA, 1 μM) in the presence of HIV-1 Tat on GABAergic neurotransmission in mouse prefrontal cortex (PFC) slices. We found a Tat concentration-dependent (5-50 nM) decrease in the frequency and amplitude of miniature inhibitory postsynaptic currents (mIPSCs). The cannabinoid 1 receptor (CB1R) antagonist rimonabant (1 μM) and zero extracellular calcium prevented the significant Tat-induced decrease in mIPSCs. Further, bath-applied WIN55,212-2 or AEA by itself, significantly decreased the frequency, but not amplitude of mIPSCs and/or spontaneous IPSCs (sIPSCs), and occluded a further downregulation of IPSCs by Tat. Pretreatment with rimonabant but not the CB2R antagonist AM630 (1 μM) prevented the WIN55,212-2- and AEA-induced decrease in IPSCs frequency without any further Tat effect. Results indicated a Tat-induced decrease in GABAergic neurotransmission, which was occluded by cannabinoids via a CB1R-related mechanism. Understanding the relationship between Tat toxicity and endocannabinoid signaling has the potential to identify novel therapeutic interventions to benefit individuals suffering from HAND and other cognitive impairments. PMID:26993829

  11. 多层螺旋 CT 灌注成像在脑胶质瘤分级中的价值与微血管密度的相关性研究%Application value of multi-slice spiral CT perfusion imaging in brain gliomas and its relation with microvessel density

    Institute of Scientific and Technical Information of China (English)

    洪建斌; 许乃滔; 侯志雄

    2014-01-01

    Objective To study the value of multi-slice spiral CT (MSCT ) perfusion imaging in grading of brain glioma(BG) and its correlation with microvessel density (MVD) .Methods A total of 89 BG patients ,treated in this hospital from March 2010 to March 2013 ,were enrolled and divided into high grade group and low grade group , according to the grading levels .MSCT parameters and MVD ,vascular endothelial growth factor(VEGF) levels were compared ,and the correlation between relative cerebral blood flow (rCBV) and MVD ,VEGF were analyzed .Results Levels of cerebral blood flow (CBF) ,rCBF ,cerebral blood volume(CBV) ,relative CBV(rCBV) of high grade group were significantly higher than low grade group (P< 0 .05) .The positive rate of VEGF in high grade group was 89 .13% (41/46) ,higher than the 55 .81% (24/43) of low grade group(P<0 .05) .Level of MVD in high grade group was 70 .76 ± 8 .85 ,significantly higher than the 37 .75 ± 5 .65 of low grade group(P<0 .05) .rCBV level was positive-ly correlated with MVD and VEGF expression level (r= 0 .610 and r= 0 .631 ,P< 0 .05) .Conclusion rCBV level could be positively correlated with MVD and VEGF expression level in patients wit BG .MSCT could provide fine im-aging evidence for the grading of BG .%目的:研究多层螺旋CT(MSCT)灌注成像在脑胶质瘤(BG)分级中的价值与微血管密度(MVD)的相关性。方法选择该院2010年3月至2013年3月诊治的89例BG患者作为观察对象,根据BG分级标准分成高级别组以及低级别组。对比两组MSCT参数以及MVD、血管内皮生长因子(VEGF);分析相对脑血容量(rCBV)和MVD、VEGF的相关性。结果高级别组的脑血流量(CBF)、相对脑血流量(rCBF)、脑血容量(CBV)、rCBV均明显高于低级别组;高级别组VEGF阳性率为89.13%(41/46),明显高于低级别组的55.81%(24/43);高级别组MVD为70.76±8.85,明显高于低级别组的37.75±5.65,差

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

    Science.gov (United States)

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

    2009-05-30

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

  13. Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the hydrogen-bonded structure of ribonucleic acid of brain-cortex ribosomes.

    Science.gov (United States)

    Datta, R K; Ghosh, J J

    1970-05-01

    1. The action of mescaline sulphate on the hydrogen-bonded structure of the RNA constituent of ribosomes of goat brain-cortex slices was studied by using the hyperchromic effect of heating and formaldehyde reaction. 2. The ribosomal total RNA species of the mescaline-treated brain-cortex slices have a smaller proportion of hydrogen-bonded structure than the ribosomal RNA species of the untreated brain-cortex slices. 3. Mescaline also appears to have affected this lowering of hydrogen-bonded structure of the ribosomal 28S RNA of brain-cortex tissue.

  14. Carbachol-induced rhythmic slow activity (theta) in cat hippocampal formation slices.

    Science.gov (United States)

    Konopacki, J; Gołebiewski, H; Eckersdorf, B

    1992-04-24

    Application of the cholinergic agonist, carbachol, produced theta-like rhythmical waveforms, recorded in the stratum moleculare of the dentate gyrus in the cat hippocampal formation slices. This effect of carbachol was antagonized by atropine but not D-tubocurarine. These results provide first direct evidence that the hippocampal formation neuronal network in the cat is capable of producing synchronized slow wave activity when isolated from pulsed rhythmic inputs of the medial septum. PMID:1511270

  15. Mechanical characteristics of native tendon slices for tissue engineering scaffold.

    Science.gov (United States)

    Qin, Ting-Wu; Chen, Qingshan; Sun, Yu-Long; Steinmann, Scott P; Amadio, Peter C; An, Kai-Nan; Zhao, Chunfeng

    2012-04-01

    The purpose of this study was to characterize the mechanical behavior of tendon slices with different thicknesses. Tendon slices of 100, 200, 300, 400, and 500 μm thickness were mechanically tested. The 300 μm slices were further tested for strength and modulus after 21,000-cycle fatigue testing under different applied strain levels (0, 1, 3, 5, 8, 10, and 12%). The tendon slice structure, morphology, and viability of bone marrow stromal cells (BMSCs) seeded onto the slices were also examined with histology, scanning electron microscopy, and vital cell labeling, respectively. Tendon slices 300 μm or more in thickness had similar ultimate tensile strength and Young's modulus to the intact tendon bundle. A strain of 5% or less did not cause any structural damage, nor did it change the mechanical properties of a 300 μm-thick tendon slice after 21,000-cycle fatigue testing. BMSCs were viable between and on the tendon slices after 2 weeks in tissue culture. This study demonstrated that, if tendon slices are used as a scaffold for tendon tissue engineering, slices 300 μm or more in thickness would be preferable from a mechanical strength point of view. If mechanical stimulation is performed for seeded-cell preparations, 5% strain or less would be appropriate.

  16. High-Resolution, Non-Invasive Imaging of Upper Vocal Tract Articulators Compatible with Human Brain Recordings.

    Directory of Open Access Journals (Sweden)

    Kristofer E Bouchard

    Full Text Available A complete neurobiological understanding of speech motor control requires determination of the relationship between simultaneously recorded neural activity and the kinematics of the lips, jaw, tongue, and larynx. Many speech articulators are internal to the vocal tract, and therefore simultaneously tracking the kinematics of all articulators is nontrivial--especially in the context of human electrophysiology recordings. Here, we describe a noninvasive, multi-modal imaging system to monitor vocal tract kinematics, demonstrate this system in six speakers during production of nine American English vowels, and provide new analysis of such data. Classification and regression analysis revealed considerable variability in the articulator-to-acoustic relationship across speakers. Non-negative matrix factorization extracted basis sets capturing vocal tract shapes allowing for higher vowel classification accuracy than traditional methods. Statistical speech synthesis generated speech from vocal tract measurements, and we demonstrate perceptual identification. We demonstrate the capacity to predict lip kinematics from ventral sensorimotor cortical activity. These results demonstrate a multi-modal system to non-invasively monitor articulator kinematics during speech production, describe novel analytic methods for relating kinematic data to speech acoustics, and provide the first decoding of speech kinematics from electrocorticography. These advances will be critical for understanding the cortical basis of speech production and the creation of vocal prosthetics.

  17. High-Resolution, Non-Invasive Imaging of Upper Vocal Tract Articulators Compatible with Human Brain Recordings

    Science.gov (United States)

    Anumanchipalli, Gopala K.; Dichter, Benjamin; Chaisanguanthum, Kris S.; Johnson, Keith; Chang, Edward F.

    2016-01-01

    A complete neurobiological understanding of speech motor control requires determination of the relationship between simultaneously recorded neural activity and the kinematics of the lips, jaw, tongue, and larynx. Many speech articulators are internal to the vocal tract, and therefore simultaneously tracking the kinematics of all articulators is nontrivial—especially in the context of human electrophysiology recordings. Here, we describe a noninvasive, multi-modal imaging system to monitor vocal tract kinematics, demonstrate this system in six speakers during production of nine American English vowels, and provide new analysis of such data. Classification and regression analysis revealed considerable variability in the articulator-to-acoustic relationship across speakers. Non-negative matrix factorization extracted basis sets capturing vocal tract shapes allowing for higher vowel classification accuracy than traditional methods. Statistical speech synthesis generated speech from vocal tract measurements, and we demonstrate perceptual identification. We demonstrate the capacity to predict lip kinematics from ventral sensorimotor cortical activity. These results demonstrate a multi-modal system to non-invasively monitor articulator kinematics during speech production, describe novel analytic methods for relating kinematic data to speech acoustics, and provide the first decoding of speech kinematics from electrocorticography. These advances will be critical for understanding the cortical basis of speech production and the creation of vocal prosthetics. PMID:27019106

  18. Temperature- and concentration-dependence of kainate-induced y oscillation in rat hippocampal slices under submerged condition

    Institute of Scientific and Technical Information of China (English)

    Cheng-biao LU; Zhi-hua WANG; Yan-hong ZHOU; Martin VREUGDENHIL

    2012-01-01

    Aim:Fast neuronal network oscillation at the y frequency band (y oscillation:30-80 Hz) has been studied extensively in hippocampal slices under interface recording condition.The aim of this study is to establish a method for recording Y oscillation in submerged hippocampal slices that allows simultaneously monitoring Y oscillation and the oscillation-related intracellular events,such as intracellular Ca2+ concentration or mitochondrial membrane potentials.Methods:Horizontal hippocampal slices (thickness:300 pm) of adult rats were prepared and placed in a submerged or an interface chamber.Extracellular field recordings Were made in the CA3c pyramidal layer of the slices.Kainate,an AMPA/kainate receptor agonist,was applied via perfusion.Data analysis was performed off-line.Results:Addition of kainate (25-1000 nmol/L) induced Y oscillation in both the submerged and interface slices.Kainate increased the Y power in a concentration-dependent manner,but the duration of steady state oscillation was reduced at higher concentrations of kainate.Long-lasting Y oscillation was maintained at the concentrations of 100-300 nmol/L.Under submerged condition,Y oscillation was temperature-dependent,with the maximum power achieved at 29℃.The induction of Y oscillation under submerged condition also required a fast rate of perfusion (5-7 mL/min) and showed a fast dynamic during development and after the washout.Conclusion:The kainite-induced Y oscillation recorded in submerged rat hippocampal slices is useful for studying the intracellular events related to neuronal network activities and may represent a model to reveal the mechanisms underlying the normal neuronal synchronizations and diseased conditions.

  19. A remark on the slicing problem

    CERN Document Server

    Giannopoulos, Apostolos; Vritsiou, Beatrice-Helen

    2011-01-01

    The purpose of this article is to describe a reduction of the slicing problem to the study of the parameter I_1(K,Z_q^o(K))=\\int_K || ||_{L_q(K)}dx. We show that an upper bound of the form I_1(K,Z_q^o(K))\\leq C_1q^s\\sqrt{n}L_K^2, with 1/2\\leq s\\leq 1, leads to the estimate L_n\\leq \\frac{C_2\\sqrt[4]{n}log(n)} {q^{(1-s)/2}}, where L_n:= max {L_K : K is an isotropic convex body in R^n}.

  20. TEST COVERAGE ANALYSIS BASED ON PROGRAM SLICING

    Institute of Scientific and Technical Information of China (English)

    Chen Zhenqiang; Xu Baowen; Guanjie

    2003-01-01

    Coverage analysis is a structural testing technique that helps to eliminate gaps in atest suite and determines when to stop testing. To compute test coverage, this letter proposes anew concept coverage about variables, based on program slicing. By adding powers accordingto their importance, the users can focus on the important variables to obtain higher test coverage.The letter presents methods to compute basic coverage based on program structure graphs. Inmost cases, the coverage obtained in the letter is bigger than that obtained by a traditionalmeasure, because the coverage about a variable takes only the related codes into account.

  1. TRANSFORM DOMAIN SLICE BASED DISTRIBUTED VIDEO CODING

    Directory of Open Access Journals (Sweden)

    SAMIR BELHOUARI

    2011-10-01

    Full Text Available Distributed video coding depends heavily on the virtual channel model. Due to the limitations of the side information estimation one stationary model does not properly describe the virtual channel. In this work the correlation noise is modelled per slice to obtain location-specific correlation noise model. The resulting delay from the lengthy Slepian-Wolf (SW codec input is also reduced by reducing the length of SW codec input. The proposed solution does not impose any extra complexity, it utilizes the existing resources. The results presented here support the proposed algorithm.

  2. A Comparative Study of Spiral Tomograms with Different Slice Thicknesses in Dental Implant Planning

    International Nuclear Information System (INIS)

    To know whether there would be a difference among spiral tomograms of different slice thicknesses in the measurement of distances which are used for dental implant planning. 10 dry mandibules and 40 metal balls are used to take total 120 Scanora tomograms with the slice thickness of 2 mm, 4 mm and 8 mm. 3 oral radiologists interpreted each tomogram to measure the distances from the mandibular canal to the alveoalr crest and buccal, lingual and inferior borders of mandible. 3 observers recorded grades of 0, 1 or 2 to evaluate the perceptibility of alveolar crest and the superior border of mandibular canal. For statistical analysis, ANOVA with repeated measure, Chi-square tests and intraclass correlation coefficient (R2, alpha) were used. There was not a statistically significant difference among spiral tomograms with different slice thicknesses in the measurement of the distances and in the perceptibility of alveolar crest and mandibular canal (p>0.05). All of them showed a good relationship in the reliability analysis. The perceptibility of alveolar crest and mandibular canal was almost similar and an excellent relationship was seen on all of them. There would be no significant difference, no matter which spiral tomogram of any slice thickness may be used in dental implant planning, considering the thickness of dental implant fixture.

  3. Functional brain network organisation of children between 2 and 5 years derived from reconstructed activity of cortical sources of high-density EEG recordings.

    Science.gov (United States)

    Bathelt, Joe; O'Reilly, Helen; Clayden, Jonathan D; Cross, J Helen; de Haan, Michelle

    2013-11-15

    There is increasing interest in applying connectivity analysis to brain measures (Rubinov and Sporns, 2010), but most studies have relied on fMRI, which substantially limits the participant groups and numbers that can be studied. High-density EEG recordings offer a comparatively inexpensive easy-to-use alternative, but require channel-level connectivity analysis which currently lacks a common analytic framework and is very limited in spatial resolution. To address this problem, we have developed a new technique for studies of network development that overcomes the spatial constraint and obtains functional networks of cortical areas by using EEG source reconstruction with age-matched average MRI templates (He et al., 1999). In contrast to previously reported channel-level analysis, this approach provides information about the cortical areas most likely to be involved in the network as well as their functional relationship (Babiloni et al., 2005; De Vico Fallani et al., 2007). In this study, we applied source reconstruction with age-matched templates to task-free high-density EEG recordings in typically-developing children between 2 and 6 years of age (O'Reilly, 2012). Graph theory was then applied to the association strengths of 68 cortical regions of interest based on the Desikan-Killiany atlas. We found linear increases of mean node degree, mean clustering coefficient and maximum betweenness centrality between 2 years and 6 years of age. Characteristic path length was negatively correlated with age. The correlation of the network measures with age indicates network development towards more closely integrated networks similar to reports from other imaging modalities (Fair et al., 2008; Power et al., 2010). We also applied eigenvalue decomposition to obtain functional modules (Clayden et al., 2013). Connection strength within these modules did not change with age, and the modules resembled hub networks previously described for MRI (Hagmann et al., 2010; Power et al

  4. CTA及动态血清S-100B蛋白检测对SAH患者脑损害程度及脑血管痉挛的评价作用%The role of multi-slice spiral CTA and serum S-100B protein in the evaluation of brain damage and cerebral vasospasm in SAH patients

    Institute of Scientific and Technical Information of China (English)

    韦英海; 吴振宏; 欧阳强; 李松柏

    2015-01-01

    Objective To investigate the diagnostic value of multi‐slice spiral CTA on the SAH patients ,and serum S‐100B pro‐tein in the evaluation of brain damage and cerebral vasospasm in SAH patients .Methods One hundred and sixty six patients with SAH were selected ,and all underwent CTA examination ,the serum S‐100B protein level were detected 1 d ,2 d ,3 d and 7 d after ad‐mission .Results In the 166 patients ,CTA showed 119 aneurysms .With the treatment ,on day 1 S‐100B protein level of Ⅰ - ⅡHunt‐Hess grade patients was (0 .71 ± 0 .11)μg/L ,on day 7 the level was (0 .62 ± 0 .09)μg/L ;S‐100B level of Hunt‐Hess Ⅳ stage patients on day 1 and 7 were (2 .12 ± 0 .23)μg/L and (1 .97 ± 0 .06)μg/L .After treatment ,S‐100B level was proportional to Hunt‐Hess grade .S‐100B protein level of GCS(3-8) score patients were (1 .87 ± 0 .23)μg/L on day 1 and (1 .87 ± 0 .23)μg/L on day 7 .S‐100B protein level of GCS(13-15) score patients were(0 .63 ± 0 .17)μg/L on day 1 ,(0 .44 ± 0 .15)μg/L on day 7 .After treat‐ment ,the S‐100B level was inversely proportional to GCS score .Conclusion CTA could display three‐dimensional structure and the surrounding relations ,and could contribute to the choice of treatment and assessment of the degree of difficulty .Serum and cerebro‐spinal fluid concentration of S‐100B protein level could be used to assess the gravity of the secondary brain damage and the possibili‐ty of cerebral vasospasm .%目的:分析讨论多层螺旋CT血管成像(CTA)对原发性蛛网膜下腔出血(SAH)患者的诊断价值及动态血清S‐100B蛋白检测SAH患者脑损害程度及脑血管痉挛的评价作用。方法对166例SAH患者行CTA检查,抽取患者入院后1、2、3、7d时的肘静脉血检测血清S‐100B蛋白水平。结果166例SAH患者中,CTA共检出119处动脉瘤。Hunt‐HessⅠ~Ⅱ级患者入院后1dS‐100B蛋白水平为(0.71±0.11)μg/L,7d为(0.62±0

  5. Effects of Temperature and Slice Thickness on Drying Kinetics of Pumpkin Slices

    Directory of Open Access Journals (Sweden)

    Kongdej LIMPAIBOON

    2011-06-01

    Full Text Available Dried pumpkin slice is an alternative crisp food product. In this study, the effects of temperature and slice thickness on the drying characteristics of pumpkin were studied in a lab-scale tray dryer, using hot air temperatures of 55, 60 and 65 °C and 2, 3 and 4 mm slice thickness at a constant air velocity of 1.5 m/s. The initial moisture content of the pumpkin samples was 900.5 % (wb. The drying process was carried out until the final moisture content of product was 100.5 % (wb. The results showed that the drying time decreased with increasing drying temperature, but it increased with increasing slice thickness of the pumpkin. In all tests, the experimental drying curves obtained show results for only the falling rate period.Fick’s diffusion equation has been used to model the drying characteristics and fits all experimental data. The effective moisture diffusivity during drying varied from 1.359×10-10 to 5.301×10-10 m2/s. The effective moisture diffusivity results were in agreement with previously reported diffusivity values.

  6. Stark effect on a geometry defined by a cake' slice

    CERN Document Server

    Reyes-Esqueda, J A; Castillo-Mussot, M; Vazquez, G J; Reyes-Esqueda, Jorge-Alejandro; Mendoza, Carlos I.; Castillo-Mussot, Marcelo del; Vazquez, Gerardo J.

    2005-01-01

    By using a variational calculation, we study the effect of an external applied electric field on the ground state of electrons confined in a quantum box with a geometry defined by a slice of a cake. This geometry is a first approximation for a tip of a cantilever of an Atomic Force Microscope (AFM). By modeling the tip with the slice, we calculate the electronic ground state energy as function of the slice's diameter, its angular aperture, its thickness and the intensity of the external electric field applied along the slice. For the applied field pointing to the wider part of the slice, a confining electronic effect in the opposite side is clearly observed. This effect is sharper as the angular slice's aperture is smaller and there is more radial space to manifest itself.

  7. The Scalable Brain Atlas: instant web-based access to public brain atlases and related content

    OpenAIRE

    Bakker, R.; Tiesinga, P.; Kotter, R.

    2013-01-01

    The Scalable Brain Atlas (SBA) is a collection of web services that provide unified access to a large collection of brain atlas templates for different species. Its main component is an atlas viewer that displays brain atlas data as a stack of slices in which stereotaxic coordinates and brain regions can be selected. These are subsequently used to launch web queries to resources that require coordinates or region names as input. It supports plugins which run inside the viewer and respond when...

  8. Thin slice CT of lung tumors

    International Nuclear Information System (INIS)

    Thin slice (2 mm) CT (CT) findings of peripheral portions of 22 solitary lung tumors (37 portions) were reviewed in comparison with pathohistologic findings. A poorly defined tumor-edge with reticular pattern on CT was found only in moderately or well differentiated adenocarcinoma and it corresponded pathohistologically to superficial tumor-cells replacement of alveolar cells without alveolar collapse. In tumors with CT findings of comparatively defined tumor-edge with linear or strand projection, tumor cells replaced alveolar cells showing alveolar collapse with slight or marked interstitial fibrosis. Especially, a linear projection finding on CT may indicate an early phase in contracting process. Invasion of cancer cells along both bronchiole and small vessels was often found in the portion corresponding to the strand projection finding on CT which indicated poorer prognosis. Comparatively defined tumor-edge with serrated projection and sharply defined tumor-edge on CT images, both of which were found mainly in tumors with cell types of poorly differentiated adenocarcinoma, squamous cell carcinoma, and undifferentiated carcinoma, showed histo-pathologically tumor-cells replacement of alveolar cavities with thickened alveolar septa and with displaced alveolar septa, respectively. A cavity-like low density area on CT which was found in adenocarcinoma was pathohistologically dilated bronchiole. Thin slice CT is useful for evaluation of the extent and growth of a tumor. (author)

  9. Understanding brain networks and brain organization

    Science.gov (United States)

    Pessoa, Luiz

    2014-09-01

    What is the relationship between brain and behavior? The answer to this question necessitates characterizing the mapping between structure and function. The aim of this paper is to discuss broad issues surrounding the link between structure and function in the brain that will motivate a network perspective to understanding this question. However, as others in the past, I argue that a network perspective should supplant the common strategy of understanding the brain in terms of individual regions. Whereas this perspective is needed for a fuller characterization of the mind-brain, it should not be viewed as panacea. For one, the challenges posed by the many-to-many mapping between regions and functions is not dissolved by the network perspective. Although the problem is ameliorated, one should not anticipate a one-to-one mapping when the network approach is adopted. Furthermore, decomposition of the brain network in terms of meaningful clusters of regions, such as the ones generated by community-finding algorithms, does not by itself reveal "true" subnetworks. Given the hierarchical and multi-relational relationship between regions, multiple decompositions will offer different "slices" of a broader landscape of networks within the brain. Finally, I described how the function of brain regions can be characterized in a multidimensional manner via the idea of diversity profiles. The concept can also be used to describe the way different brain regions participate in networks.

  10. Accuracy and safety of targeting using intraoperative "O-arm" during placement of deep brain stimulation electrodes without electrophysiological recordings.

    Science.gov (United States)

    Sharma, Mayur; Deogaonkar, Milind

    2016-05-01

    The aim of our study was to investigate the accuracy of targeting using intraoperative "O-arm" during deep brain stimulation (DBS) surgery. Intraoperative O-arm (Medtronic, Minneapolis, MN, USA) images were obtained to confirm the accuracy of placement. The difference between intended and actual target coordinates was calculated based on intraoperative images and postoperative CT scan. Euclidian vector error was obtained to estimate the directional error. Correlation of targeting error with the pneumocephalus and the deviation from the planned trajectory was also estimated. Twenty eight DBS leads (globus pallidus internus [GPi], n=13; subthalamic nucleus [STN], n=9; ventralis intermedius nucleus [VIM], n=6) were implanted in 20 patients using the stereotactic Leksell frame (Elekta AB, Stockholm, Sweden) under general anesthesia over a period of 1year. The mean age was 63.6±standard error of the mean (SEM) 15.7years and 60% of patients were males. The mean absolute difference (+SEM) between intended and actual target in x, y and z coordinates based on intraoperative CT scan was 0.65±0.09 (p=0.84), 0.58±0.08 (p=0.98), 1.13±0.10 (p=0.08), respectively, and postoperative (1month) CT scan was 0.82±0.15 (p=0.89), 0.55±0.11 (p=0.97), and 1.58±0.29 (p=0.08), respectively. The Euclidean vector error was 1.59±0.10 and 2.16±0.26 based on intraoperative and postoperative images, respectively. There was no statistically significant targeting error based on fusion of intraoperative CT images to either preoperative CT scan or MRI as registration series, the presence of pneumocephalus, deviation from planned trajectory or the anatomical target (STN versus VIM versus GPi) (p>0.05). Superficial skin infection was encountered in a single patient in this study. The mean total operating room time was 193.5±74.6 minutes. None of the patients required revision in our study. DBS leads can be implanted safely and accurately using intraoperative O-arm with a frame based targeting

  11. Thin slices of child personality: Perceptual, situational, and behavioral contributions.

    Science.gov (United States)

    Tackett, Jennifer L; Herzhoff, Kathrin; Kushner, Shauna C; Rule, Nicholas

    2016-01-01

    The present study examined whether thin-slice ratings of child personality serve as a resource-efficient and theoretically valid measurement of child personality traits. We extended theoretical work on the observability, perceptual accuracy, and situational consistency of childhood personality traits by examining intersource and interjudge agreement, cross-situational consistency, and convergent, divergent, and predictive validity of thin-slice ratings. Forty-five unacquainted independent coders rated 326 children's (ages 8-12) personality in 1 of 15 thin-slice behavioral scenarios (i.e., 3 raters per slice, for over 14,000 independent thin-slice ratings). Mothers, fathers, and children rated children's personality, psychopathology, and competence. We found robust evidence for correlations between thin-slice and mother/father ratings of child personality, within- and across-task consistency of thin-slice ratings, and convergent and divergent validity with psychopathology and competence. Surprisingly, thin-slice ratings were more consistent across situations in this child sample than previously found for adults. Taken together, these results suggest that thin slices are a valid and reliable measure to assess child personality, offering a useful method of measurement beyond questionnaires, helping to address novel questions of personality perception and consistency in childhood.

  12. Particle swarm optimization and its application in MEG source localization using single time sliced data

    Science.gov (United States)

    Lin, Juan; Liu, Chenglian; Guo, Yongning

    2014-10-01

    The estimation of neural active sources from the magnetoencephalography (MEG) data is a very critical issue for both clinical neurology and brain functions research. A widely accepted source-modeling technique for MEG involves calculating a set of equivalent current dipoles (ECDs). Depth in the brain is one of difficulties in MEG source localization. Particle swarm optimization(PSO) is widely used to solve various optimization problems. In this paper we discuss its ability and robustness to find the global optimum in different depths of the brain when using single equivalent current dipole (sECD) model and single time sliced data. The results show that PSO is an effective global optimization to MEG source localization when given one dipole in different depths.

  13. Dopamine modulates Spike Timing-Dependent Plasticity and action potential properties in CA1 pyramidal neurons of acute rat hippocampal slices

    Directory of Open Access Journals (Sweden)

    Elke eEdelmann

    2011-11-01

    Full Text Available Spike Timing-Dependent Plasticity (STDP is a cellular model of hebbian synaptic plasticity which is believed to underlie memory formation. In an attempt to establish a STDP paradigm in CA1 of acute hippocampal slices from juvenile rats (P15-20, we found that changes in excitability resulting from different slice preparation protocols correlate with the success of STDP induction. Slice preparation with sucrose containing ACSF prolonged rise time, reduced frequency adaptation, and decreased latency of action potentials in CA1 pyramidal neurons compared to preparation in conventional ASCF, while other basal electrophysiological parameters remained unaffected. Whereas we observed prominent timing-dependent (t-LTP to 171 ± 10% of controls in conventional ACSF, STDP was absent in sucrose prepared slices. This sucrose-induced STDP deficit could not be rescued by stronger STDP paradigms, applying either more pre- and/or postsynaptic stimuli, or by a higher stimulation frequency. Importantly, slice preparation with sucrose containing ACSF did not eliminate theta-burst stimulation induced LTP in CA1 in field potential recordings in our rat hippocampal slices. Application of dopamine (for 10-20 min to sucrose prepared slices completely rescued t-LTP and recovered action potential properties back to levels observed in ACSF prepared slices. Conversely, acute inhibition of D1 receptor signaling impaired t-LTP in ACSF prepared slices. No similar restoring effect for STDP as seen with dopamine was observed in response to the β-adrenergic agonist isoproterenol. ELISA measurements demonstrated a significant reduction of endogenous dopamine levels (to 61.9 ± 6.9% of ACSF values in sucrose prepared slices. These results lead us to suggest that dopamine dependent regulation of action potential properties correlates with the efficiency to elicit STDP in CA1 pyramidal neurons.

  14. Slicing the Torus: Obscuring Structures in Quasars

    Science.gov (United States)

    Elvis, Martin

    2012-07-01

    Quasars and Active Galactic Nuclei (AGNs) are often obscured by dust and gas. It is normally assumed that the obscuration occurs in an oblate "obscuring torus", that begins at the radius at which the most refractive dust can remain solid. The most famous form of this torus is a donut-shaped region of molecular gas with a large scale-height. While this model is elegant and accounts for many phenomena at once, it does not hold up to detailed tests. Instead the obscuration in AGNs must occur on a wide range of scales and be due to a minimum of three physically distinct absorbers. Slicing the "torus" into these three regions will allow interesting physics of the AGN to be extracted.

  15. Slicing the Torus: Obscuring Structures in Quasars

    International Nuclear Information System (INIS)

    Quasars and Active Galactic Nuclei (AGNs) are often obscured by dust and gas. It is normally assumed that the obscuration occurs in an oblate 'obscuring torus', that begins at the radius at which the most refractive dust can remain solid. The most famous form of this torus is a donut-shaped region of molecular gas with a large scale-height. While this model is elegant and accounts for many phenomena at once, it does not hold up to detailed tests. Instead the obscuration in AGNs must occur on a wide range of scales and be due to a minimum of three physically distinct absorbers. Slicing the 'torus' into these three regions will allow interesting physics of the AGN to be extracted.

  16. Slicing the Torus: Obscuring Structures in Quasars

    CERN Document Server

    Elvis, Martin

    2012-01-01

    Quasars and Active Galactic Nuclei (AGNs) are often obscured by dust and gas. It is normally assumed that the obscuration occurs in an oblate "obscuring torus", that begins at the radius at which the most refractive dust can remain solid. The most famous form of this torus is a donut-shaped region of molecular gas with a large scale-height. While this model is elegant and accounts for many phenomena at once, it does not hold up to detailed tests. Instead the obscuration in AGNs must occur on a wide range of scales and be due to a minimum of three physically distinct absorbers. Slicing the "torus" into these three regions will allow interesting physics of the AGN to be extracted.

  17. On spline approximation of sliced inverse regression

    Institute of Scientific and Technical Information of China (English)

    Li-ping ZHU; Zhou YU

    2007-01-01

    The dimension reduction is helpful and often necessary in exploring the nonparametric regression structure. In this area, Sliced inverse regression (SIR) is a promising tool to estimate the central dimension reduction (CDR) space. To estimate the kernel matrix of the SIR, we herein suggest the spline approximation using the least squares regression. The heteroscedasticity can be incorporated well by introducing an appropriate weight function. The root-n asymptotic normality can be achieved for a wide range choice of knots. This is essentially analogous to the kernel estimation. Moreover,we also propose a modified Bayes information criterion (BIC) based on the eigenvalues of the SIR matrix. This modified BIC can be applied to any form of the SIR and other related methods. The methodology and some of the practical issues are illustrated through the horse mussel data. Empirical studies evidence the performance of our proposed spline approximation by comparison of the existing estimators.

  18. Time-lapse imaging of neuroblast migration in acute slices of the adult mouse forebrain.

    Science.gov (United States)

    Khlghatyan, Jivan; Saghatelyan, Armen

    2012-01-01

    There is a substantial body of evidence indicating that new functional neurons are constitutively generated from an endogenous pool of neural stem cells in restricted areas of the adult mammalian brain. Newborn neuroblasts from the subventricular zone (SVZ) migrate along the rostral migratory stream (RMS) to their final destination in the olfactory bulb (OB). In the RMS, neuroblasts migrate tangentially in chains ensheathed by astrocytic processes using blood vessels as a structural support and a source of molecular factors required for migration. In the OB, neuroblasts detach from the chains and migrate radially into the different bulbar layers where they differentiate into interneurons and integrate into the existing network. In this manuscript we describe the procedure for monitoring cell migration in acute slices of the rodent brain. The use of acute slices allows the assessment of cell migration in the microenvironment that closely resembling to in vivo conditions and in brain regions that are difficult to access for in vivo imaging. In addition, it avoids long culturing condition as in the case of organotypic and cell cultures that may eventually alter the migration properties of the cells. Neuronal precursors in acute slices can be visualized using DIC optics or fluorescent proteins. Viral labeling of neuronal precursors in the SVZ, grafting neuroblasts from reporter mice into the SVZ of wild-type mice, and using transgenic mice that express fluorescent protein in neuroblasts are all suitable methods for visualizing neuroblasts and following their migration. The later method, however, does not allow individual cells to be tracked for long periods of time because of the high density of labeled cells. We used a wide-field fluorescent upright microscope equipped with a CCD camera to achieve a relatively rapid acquisition interval (one image every 15 or 30 sec) to reliably identify the stationary and migratory phases. A precise identification of the duration of

  19. Mathematical Modeling of Thin Layer Microwave Drying of Taro Slices

    Science.gov (United States)

    Kumar, Vivek; Sharma, H. K.; Singh, K.

    2016-03-01

    The present study investigated the drying kinetics of taro slices precooked in different medium viz water (WC), steam (SC) and Lemon Solution (LC) and dried at different microwave power 360, 540 and 720 W. Drying curves of all precooked slices at all microwave powers showed falling rate period along with a very short accelerating period at the beginning of the drying. At all microwave powers, higher drying rate was observed for LC slices as compared to WC and SC slices. To select a suitable drying curve, seven thin-layer drying models were fitted to the experimental data. The data revealed that the Page model was most adequate in describing the microwave drying behavior of taro slices precooked in different medium. The highest effective moisture diffusivity value of 2.11 × 10-8 m2/s was obtained for LC samples while the lowest 0.83 × 10-8 m2/s was obtained for WC taro slices. The activation energy (E a ) of LC taro slices was lower than the E a of WC and SC taro slices.

  20. Target recognition for ladar range image using slice image

    Science.gov (United States)

    Xia, Wenze; Han, Shaokun; Wang, Liang

    2015-12-01

    A shape descriptor and a complete shape-based recognition system using slice images as geometric feature descriptor for ladar range images are introduced. A slice image is a two-dimensional image generated by three-dimensional Hough transform and the corresponding mathematical transformation. The system consists of two processes, the model library construction and recognition. In the model library construction process, a series of range images are obtained after the model object is sampled at preset attitude angles. Then, all the range images are converted into slice images. The number of slice images is reduced by clustering analysis and finding a representation to reduce the size of the model library. In the recognition process, the slice image of the scene is compared with the slice image in the model library. The recognition results depend on the comparison. Simulated ladar range images are used to analyze the recognition and misjudgment rates, and comparison between the slice image representation method and moment invariants representation method is performed. The experimental results show that whether in conditions without noise or with ladar noise, the system has a high recognition rate and low misjudgment rate. The comparison experiment demonstrates that the slice image has better representation ability than moment invariants.

  1. Design and Development of a tomato Slicing Machine

    Directory of Open Access Journals (Sweden)

    Kamaldeen Oladimeji Salaudeen

    2012-11-01

    Full Text Available Principle of slicing was reviewed and tomato slicing machine was developed based on appropriate technology. Locally available materials like wood, stainless steel and mild steel were used in the fabrication. The machine was made to cut tomatoes in 2cm thickness. The capacity of the machine is 540.09g per minute and its performance efficiency is 70%.

  2. Study and Improvement for Slice Smoothness in Slicing Machine of Lotus Root

    OpenAIRE

    YANG, DEYONG; Hu, Jianping; Wei, Enzhu; Lei, Hengqun; Kong, Xiangci

    2010-01-01

    International audience Concerning the problem of the low cutting quality and the bevel edge in the piece of lotus root, the reason was analyzed and the method of improvement was to reduce the force in the vertical direction of link to knife. 3D parts and assemblies of cutting mechanism in slicing machine of lotus root were created under Pro/E circumstance. Based on virtual prototype technology, the kinematics and dynamics analysis of cutting mechanism was simulated with ADAMS software, the...

  3. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    Directory of Open Access Journals (Sweden)

    Anders Victor ePetersen

    2015-10-01

    Full Text Available The axon initial segment (AIS is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recoding of extracellular local field potentials and whole-cell patch-clamp recording of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from the brain.

  4. The developmental expression of fluorescent proteins in organotypic hippocampal slice cultures from transgenic mice and its use in the determination of excitotoxic neurodegeneration

    DEFF Research Database (Denmark)

    Noraberg, Jens; Jensen, Carsten V; Bonde, Christian;

    2007-01-01

    changes, as well as the opportunity to monitor reversible changes or long-term effects in the event of minor damage. As a first step, we present: a) the developmental expression in organotypic hippocampal brain slice cultures of transgenic fluorescent proteins, useful for the visualisation of neuronal...

  5. A Hierarchical Slicing Tool Model%一个分层切片工具模型

    Institute of Scientific and Technical Information of China (English)

    谭毅; 朱平; 李必信; 郑国梁

    2001-01-01

    Most of the traditional methods of slicing are based on dependence graph. But constructing dependence graph for object oriented programs directly is very complicated. The design and implementation of a hierarchical slicing tool model are described. By constructing the package level dependence graph, class level dependence graph, method level dependence graph and statement level dependence graph, package level slice, class level slice, method level slice and program slice are obtained step by step.

  6. Attack diagnosis on binary executables using dynamic program slicing

    Science.gov (United States)

    Huang, Shan; Zheng, Yudi; Zhang, Ruoyu

    2011-12-01

    Nowadays, the level of the practically used programs is often complex and of such a large scale so that it is not as easy to analyze and debug them as one might expect. And it is quite difficult to diagnose attacks and find vulnerabilities in such large-scale programs. Thus, dynamic program slicing becomes a popular and effective method for program comprehension and debugging since it can reduce the analysis scope greatly and drop useless data that do not influence the final result. Besides, most of existing dynamic slicing tools perform dynamic slicing in the source code level, but the source code is not easy to obtain in practice. We believe that we do need some kinds of systems to help the users understand binary programs. In this paper, we present an approach of diagnosing attacks using dynamic backward program slicing based on binary executables, and provide a dynamic binary slicing tool named DBS to analyze binary executables precisely and efficiently. It computes the set of instructions that may have affected or been affected by slicing criterion set in certain location of the binary execution stream. This tool also can organize the slicing results by function call graphs and control flow graphs clearly and hierarchically.

  7. On spline approximation of sliced inverse regression

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dimension reduction is helpful and often necessary in exploring the nonparametric regression structure.In this area,Sliced inverse regression (SIR) is a promising tool to estimate the central dimension reduction (CDR) space.To estimate the kernel matrix of the SIR,we herein suggest the spline approximation using the least squares regression.The heteroscedasticity can be incorporated well by introducing an appropriate weight function.The root-n asymptotic normality can be achieved for a wide range choice of knots.This is essentially analogous to the kernel estimation.Moreover, we also propose a modified Bayes information criterion (BIC) based on the eigenvalues of the SIR matrix.This modified BIC can be applied to any form of the SIR and other related methods.The methodology and some of the practical issues are illustrated through the horse mussel data.Empirical studies evidence the performance of our proposed spline approximation by comparison of the existing estimators.

  8. A 3D Model Reconstruction Method Using Slice Images

    Institute of Scientific and Technical Information of China (English)

    LI Hong-an; KANG Bao-sheng

    2013-01-01

    Aiming at achieving the high accuracy 3D model from slice images, a new model reconstruction method using slice im-ages is proposed. Wanting to extract the outermost contours from slice images, the method of the improved GVF-Snake model with optimized force field and ray method is employed. And then, the 3D model is reconstructed by contour connection using the im-proved shortest diagonal method and judgment function of contour fracture. The results show that the accuracy of reconstruction 3D model is improved.

  9. Brain blood flow studies with single photon emission computed tomography in patients with plateau waves

    International Nuclear Information System (INIS)

    The authors studied brain blood flow with single photon emission computed tomography (SPECT) in two patients with plateau waves. The intracranial pressure and blood pressure were also monitored continuously in these patients. They included one patient with brain-tumor (rt. sphenoid ridge meningioma) and another with hydrocephalus after subarachnoid hemorrhage due to rupture of lt. internal carotid aneurysm. The intracranial pressure was monitored through an indwelling ventricular catheter attached to a pressure transducer. The blood pressure was recorded through an intraarterial catheter placed in the dorsalis pedis artery. Brain blood flow was studied with Headtome SET-011 (manufactured by Shimazu Co., Ltd.). For this flow measurement study, an intravenous injection of Xenon-133 of about 30 mCi was given via an antecubital vein. The position of the slice for the SPECT was selected so as to obtain information not only from the cerebral hemisphere but also from the brain stem : a cross section 25 deg over the orbito-meatal line, passing through the inferior aspect of the frontal horn, the basal ganglia, the lower recessus of the third ventricle and the brain stem. The results indicated that, in the cerebral hemisphere, plateau waves were accompanied by a decrease in blood flow, whereas, in the brain stem, the blood flow showed little change during plateau waves as compared with the interval phase between two plateau waves. These observations may explain why there is no rise in the blood pressure and why patients are often alert during plateau waves. (author)

  10. Drug resistance in cortical and hippocampal slices from resected tissue of epilepsy patients: no significant impact of P-glycoprotein and Multidrug resistance associated proteins.

    Directory of Open Access Journals (Sweden)

    Nora eSandow

    2015-02-01

    Full Text Available Drug resistant patients undergoing epilepsy surgery have a good chance to become sensitive to anticonvulsant medication, suggesting that the resected brain tissue is responsible for drug resistance. Here, we address the question whether P-glycoprotein (Pgp and multidrug resistance associated proteins (MRPs expressed in the resected tissue contribute to drug resistance in vitro. Effects of anti-epileptic drugs (carbamazepine, sodium valproate, phenytoin and two unspecific inhibitors of Pgp and MRPs (verapamil and probenecid on seizure-like events induced in slices from 35 hippocampal and 35 temporal cortex specimens of altogether 51 patients (161 slices were studied. Although in slice preparations the blood brain barrier is not functional, we found that seizure-like events predominantly persisted in the presence of anticonvulsant drugs (90% and also in the presence of verapamil and probenecid (86%. Following subsequent co-administration of antiepileptic drugs and drug transport inhibitors, seizure-like events continued in 63% of 143 slices. Drug sensitivity in slices was recognized either as transition to recurrent epileptiform transients (30% or as suppression (7%, particularly by perfusion with carbamazepine in probenecid containing solutions (43%, 9%. Summarizing responses to co-administration from more than one slice per patient revealed that suppression of seizure-like activity in all slices was only observed in 7 % of patients. Patients whose tissue was completely or partially sensitive (65 % presented with higher seizure frequencies than those with resistant tissue (35 %. However, corresponding subgroups of patients don’t differ with respect to expression rates of drug transporters. Our results imply that parenchymal MRPs and Pgp are not responsible for drug resistance in resected tissue.

  11. Study of Energy Consumption of Potato Slices During Drying Process

    Directory of Open Access Journals (Sweden)

    Hafezi Negar

    2015-06-01

    Full Text Available One of the new methods of food drying using infrared heating under vacuum is to increase the drying rate and maintain the quality of dried product. In this study, potato slices were dried using vacuum-infrared drying. Experiments were performed with the infrared lamp power levels 100, 150 and 200 W, absolute pressure levels 20, 80, 140 and 760 mmHg, and with three thicknesses of slices 1, 2 and 3 mm, in three repetitions. The results showed that the infrared lamp power, absolute pressure and slice thickness have important effects on the drying of potato. With increasing the radiation power, reducing the absolute pressure (acts of vacuum in the dryer chamber and also reducing the thickness of potato slices, drying time and the amount of energy consumed is reduced. In relation to thermal utilization efficiency, results indicated that with increasing the infrared radiation power and decreasing the absolute pressure, thermal efficiency increased.

  12. Antagonist properties of (−)-pindolol and WAY 100635 at somatodendritic and postsynaptic 5-HT1A receptors in the rat brain

    OpenAIRE

    Corradetti, Renato; Laaris, Nora; Hanoun, Naima; Laporte, Anne-Marie; Le Poul, Emmanuel; Hamon, Michel; Lanfumey, Laurence

    1998-01-01

    The aim of the present work was to characterize the 5-hydroxytryptamine1A (5-HT1A) antagonistic actions of (−)-pindolol and WAY 100635 (N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl) cyclohexane carboxamide). Studies were performed on 5-HT1A receptors located on 5-hydroxytryptaminergic neurones in the dorsal raphe nucleus (DRN) and on pyramidal cells in the CA1 and CA3 regions of the hippocampus in rat brain slices.Intracellular electrophysiological recording of CA1 pyramidal ...

  13. Effect of the nootropic drug oxiracetam on field potentials of rat hippocampal slices.

    OpenAIRE

    Pugliese, A. M.; Corradetti, R.; Ballerini, L.; Pepeu, G.

    1990-01-01

    1. The effect of the nootropic drug oxiracetam on hippocampal neurotransmission was investigated in the CA1 region of the rat hippocampal slice in vitro by use of extracellular recordings. 2. Superfusion of oxiracetam (0.1-100 microM) produced a concentration-dependent, wash-resistant (greater than 90 min), increase in initial slope and amplitude of the dendritic field excitatory postsynaptic potential (e.p.s.p.). This increase was maximal at a concentration of 1 microM (70%). 3. Input-output...

  14. 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.

  15. Dynamic Frequency Allocation in SLICE Considering both BER and Distance

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2012-11-01

    Full Text Available Proposed in this paper is a dynamic resource-aware routing and frequency slots allocation scheme with consideration of both BER requirement and distance adaptive modulation (RA-BERR-DA for spectrum-sliced elastic optical path networks (SLICE.Numerical simulations are conducted to analysis network performance such as blocking rate and the number of used frequency slots. The results demonstrate that this scheme is able to decrease traffic blocking and improve resource utilization in dynamic spectrum assignment.

  16. Multiple-bipolar-tap tunable spectrum sliced microwave photonic filter.

    Science.gov (United States)

    Chen, Tong; Yi, Xiaoke; Huang, Thomas; Minasian, Robert A

    2010-12-01

    A spectrum sliced microwave photonic signal processor structure, which is all-fiber based and features simplicity, together with the ability to realize tunability, reconfigurability, bipolar taps, and multiple-tap rf filtering, is presented. It is based on thermally controlled optical slicing filters induced into two linearly chirped fiber Bragg gratings. Experimental results demonstrate the realization of versatile microwave photonic filters with frequency tunable, reconfiguration, and bipolar-tap generation capabilities. PMID:21124570

  17. Combined infrared-vacuum drying of pumpkin slices.

    Science.gov (United States)

    Ghaboos, Seyyed Hossein Hosseini; Ardabili, Seyed Mahdi Seyedain; Kashaninejad, Mahdi; Asadi, Gholamhassan; Aalami, Mehran

    2016-05-01

    Infrared-vacuum dehydration characteristics of pumpkin (Cucurbita moschata) were evaluated in a combined dryer system. The effects of drying parameters, infrared radiation power (204-272 W), system pressure (5-15 kPa), slice thickness (5 and 7 mm) and time (0-220 min) on the drying kinetics and characteristics of pumpkin slices were investigated. The vacuum pressure, lamp power and slice had significant effect on the drying kinetics and various qualities of the dried pumpkin. Moisture ratios were fitted to 10 different mathematical equations using nonlinear regression analysis. The quadratic equation satisfactorily described the drying behavior of pumpkin slices with the highest r value and the lowest SE values. The effective moisture diffusivity increased with power and ranged between 0.71 and 2.86 × 10(-9) m(2)/s. With increasing in infrared radiation power from 204 to 272 W, β-carotene content of dried pumpkins decreased from 30.04 to 24.55 mg/100 g. The rise in infrared power has a negative effect on the color changes (ΔE). The optimum condition was determined as power, 238W, pressure, 5 kPa and slice thickness, 5mm. These conditions resulted into dried pumpkin slices with maximum B-carotene retention.

  18. Combined infrared-vacuum drying of pumpkin slices.

    Science.gov (United States)

    Ghaboos, Seyyed Hossein Hosseini; Ardabili, Seyed Mahdi Seyedain; Kashaninejad, Mahdi; Asadi, Gholamhassan; Aalami, Mehran

    2016-05-01

    Infrared-vacuum dehydration characteristics of pumpkin (Cucurbita moschata) were evaluated in a combined dryer system. The effects of drying parameters, infrared radiation power (204-272 W), system pressure (5-15 kPa), slice thickness (5 and 7 mm) and time (0-220 min) on the drying kinetics and characteristics of pumpkin slices were investigated. The vacuum pressure, lamp power and slice had significant effect on the drying kinetics and various qualities of the dried pumpkin. Moisture ratios were fitted to 10 different mathematical equations using nonlinear regression analysis. The quadratic equation satisfactorily described the drying behavior of pumpkin slices with the highest r value and the lowest SE values. The effective moisture diffusivity increased with power and ranged between 0.71 and 2.86 × 10(-9) m(2)/s. With increasing in infrared radiation power from 204 to 272 W, β-carotene content of dried pumpkins decreased from 30.04 to 24.55 mg/100 g. The rise in infrared power has a negative effect on the color changes (ΔE). The optimum condition was determined as power, 238W, pressure, 5 kPa and slice thickness, 5mm. These conditions resulted into dried pumpkin slices with maximum B-carotene retention. PMID:27407204

  19. NMR surprizes with thin slices and strong gradients

    Energy Technology Data Exchange (ETDEWEB)

    Gaedke, Achim; Kresse, Benjamin [Institute of Condensed Matter Physics, Technische Universitaet Darmstadt (Germany); Nestle, Nikolaus

    2008-07-01

    In the context of our work on diffusion-relaxation-coupling in thin excited slices, we perform NMR experiments in static magnetic field gradients up to 200 T/m. For slice thicknesses in the range of 10{mu}m, the frequency bandwidth of the excited slices becomes sufficiently narrow that free induction decays (FIDs) become observable despite the presence of the strong static gradient. The observed FIDs were also simulated using standard methods from MRI physics. Possible effects of diffusion during the FID duration are still minor at this slice thickness in water but might become dominant for smaller slices or more diffusive media. Furthermore, the detailed excitation structure of the RF pulses was studied in profiling experiments over the edge of a plane liquid cell. Side lobe effects to the slices will be discussed along with approaches to control them. The spatial resolution achieved in the profiling experiments furthermore allows the identification of thermal expansion phenomena in the NMR magnet. Measures to reduce the temperature drift problems are presented.

  20. Holographic photolysis for multiple cell stimulation in mouse hippocampal slices.

    Directory of Open Access Journals (Sweden)

    Morad Zahid

    Full Text Available BACKGROUND: Advanced light microscopy offers sensitive and non-invasive means to image neural activity and to control signaling with photolysable molecules and, recently, light-gated channels. These approaches require precise and yet flexible light excitation patterns. For synchronous stimulation of subsets of cells, they also require large excitation areas with millisecond and micrometric resolution. We have recently developed a new method for such optical control using a phase holographic modulation of optical wave-fronts, which minimizes power loss, enables rapid switching between excitation patterns, and allows a true 3D sculpting of the excitation volumes. In previous studies we have used holographic photololysis to control glutamate uncaging on single neuronal cells. Here, we extend the use of holographic photolysis for the excitation of multiple neurons and of glial cells. METHODS/PRINCIPAL FINDINGS: The system combines a liquid crystal device for holographic patterned photostimulation, high-resolution optical imaging, the HiLo microscopy, to define the stimulated regions and a conventional Ca(2+ imaging system to detect neural activity. By means of electrophysiological recordings and calcium imaging in acute hippocampal slices, we show that the use of excitation patterns precisely tailored to the shape of multiple neuronal somata represents a very efficient way for the simultaneous excitation of a group of neurons. In addition, we demonstrate that fast shaped illumination patterns also induce reliable responses in single glial cells. CONCLUSIONS/SIGNIFICANCE: We show that the main advantage of holographic illumination is that it allows for an efficient excitation of multiple cells with a spatiotemporal resolution unachievable with other existing approaches. Although this paper focuses on the photoactivation of caged molecules, our approach will surely prove very efficient for other probes, such as light-gated channels, genetically

  1. 64-slice Computed Tomography Assessment of Coronary Artery Stents: a Phantom Study

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, A.H.; Muehlenbruch, G.; Seyfarth, T.; Flohr, T.; Stanzel, S.; Wildberger, J.E.; Guenther, R.W.; Kuettner, A. [Aachen Univ. of Technology (Germany). Dept. of Diagnostic Radiology

    2006-02-15

    Purpose: To compare the use of a new 64-slice computed tomography (CT) scanner with 16-slice CT in the visualization of coronary artery stent lumen. Material and Methods: Eight different coronary artery stents, each with a diameter of 3 mm, were placed in a static chest phantom. The phantom was positioned in the CT gantry at an angle of 0 deg and 45 deg towards the z-axis and examined with both a 64-slice and a 16-slice CT scanner. Effective slice thickness was 0.6 mm with 64-slice CT and 1 mm with 16-slice CT. A reconstruction increment of 0.3 mm was applied in both scanners. Image quality was assessed visually using a 5-point grading scale. Stent diameters were measured and compared using paired Wilcoxon tests. Results: Artificial lumen reduction was significantly less with 64-slice than with 16-slice CT. Average visible stent lumen was 53.4% using 64-slice CT and 47.5% with 16-slice MSCT. Most severe artifacts were seen in stents with radiopaque markers. Using 64-slice CT, image noise increased by approximately 30% due to thinner slice thickness. Conclusion: Improved spatial resolution of 64-slice CT resulted in superior assessment of coronary artery stent lumen compared to 16-slice CT. However, a relevant part of the stent lumen is still not assessable with multi-slice CT.

  2. 31P-NMR studies on membrane phospholipids in microsomes, rat liver slices and intact perfused rat liver

    NARCIS (Netherlands)

    Kruijff, B. de; Rietveld, A.; Cullis, P.R.

    1980-01-01

    1. 1. The 36.4 and 81 MHz 31P-NMR spectra of isolated rat liver microsomes, rat liver slices and perfused rat liver have been recorded in the 4–40°C temperature range. 2. 2. In isolated microsomes at 37°C the majority of the phospholipids undergo isotropic motion, whereas at 4°C most of the phospho

  3. Cellular responses to stress: comparison of a family of 71--73-kilodalton proteins rapidly synthesized in rat tissue slices and canavanine-treated cells in culture.

    Science.gov (United States)

    Hightower, L E; White, F P

    1981-08-01

    Cultured rat embryo cells exposed to the L-arginine analogue L-canavanine rapidly accumulated a major 71 kilodalton polypeptide and several minor ones (110, 95, 88, and 78 kilodaltons). Canavanine-treated cultures contained elevated levels of translatable mRNA encoding P71, and the stimulated synthesis of this protein was blocked by actinomycin D, suggesting that P71 is inducible. Rat embryo cells maintained under routine culture conditions synthesized only trace amounts of P71; however, they accumulated an abundant 73 kilodalton protein that was closely related to P71. No kinetic evidence of a precursor-product relationship between P73 and P71 was found. The peptide map of P71 from cultured cells was identical to the map of proteins with the same electrophoretic mobility isolated from incubated slices of rat telencephalon. Previous studies (White, '80a, b, c) have shown that the latter proteins are rapidly synthesized by cells associated with cerebral microvessels in incubated brain slices, but are not detectable in vivo. Herein we present evidence that the synthesis of P71 is not unique to brain slices. Incubated slices of heart, lung, thymus, kidney, spleen, and liver all accumulated an abundant 71 kilodalton size class. The peptide maps of P71 obtained from brain, heart, lung and thymus tissue were similar. The stimulated synthesis of P71 in brain, heart, and lung slices was inhibited strongly by the addition of actinomycin D at the start of incubation. The 71-73 kilodalton proteins of canavanine-treated rat embryo cells and incubated slices from seven different organs were compared in detail on two-dimensional polyacrylamide gels. Eight charge variants were detected in extracts of lung, spleen, and thymus tissue, four in liver and heart, three in kidney, and two different pairs of variants in extracts of brain tissue and cultured cells. The possible significance of the rapid synthesis of a similar small set of proteins in tissue slices and cultured cells in

  4. Mescaline-induced changes of brain-cortex ribosomes. Role of sperimidine in counteracting the destabilizing effect of mescaline of brain-cortex ribosomes.

    Science.gov (United States)

    Datta, R K; Antopol, W; Ghosh, J J

    1971-11-01

    1. The effect of spermidine on the mescaline-induced changes of brain-cortex ribosomes was studied by adding spermidine during the treatment of goat brain-cortex slices with mescaline. 2. Mescaline treatment of brain-cortex slices removed a portion of the endogenous spermidine from ribosomes and this removal was significantly prevented when spermidine was present during mescaline treatment. 3. Spermidine present during mescaline treatment of brain-cortex slices counteracted, to some extent, the destabilizing effect of mescaline on ribosomes with respect to heat denaturation. 4. Mescaline treatment of brain-cortex slices made ribosomes more susceptible to breakdown, releasing protein and RNA, and resulting in loss of ribosomal enzymic activities. However, spermidine present during mescaline treatment counteracted moderately the mescaline-induced ribosomal susceptibility to breakdown and ribosomal loss of enzymic activities. 5. Ribosomes of mescaline-treated cortex slices were rapidly degraded by ribonuclease and trypsin. However, if spermidine was present during mescaline treatment of brain-cortex slices the rates of degradation diminished.

  5. Preparation and Applications of Organotypic Thymic Slice Cultures.

    Science.gov (United States)

    Sood, Aditi; Dong, Mengqi; Melichar, Heather J

    2016-01-01

    Thymic selection proceeds in a unique and highly organized thymic microenvironment resulting in the generation of a functional, self-tolerant T cell repertoire. In vitro models to study T lineage commitment and development have provided valuable insights into this process. However, these systems lack the complete three-dimensional thymic milieu necessary for T cell development and, therefore, are incomplete approximations of in vivo thymic selection. Some of the challenges related to modeling T cell development can be overcome by using in situ models that provide an intact thymic microenvironment that fully supports thymic selection of developing T cells. Thymic slice organotypic cultures complement existing in situ techniques. Thymic slices preserve the integrity of the thymic cortical and medullary regions and provide a platform to study development of overlaid thymocytes of a defined developmental stage or of endogenous T cells within a mature thymic microenvironment. Given the ability to generate ~20 slices per mouse, thymic slices present a unique advantage in terms of scalability for high throughput experiments. Further, the relative ease in generating thymic slices and potential to overlay different thymic subsets or other cell populations from diverse genetic backgrounds enhances the versatility of this method. Here we describe a protocol for the preparation of thymic slices, isolation and overlay of thymocytes, and dissociation of thymic slices for flow cytometric analysis. This system can also be adapted to study non-conventional T cell development as well as visualize thymocyte migration, thymocyte-stromal cell interactions, and TCR signals associated with thymic selection by two-photon microscopy. PMID:27585240

  6. Evaluation of slice accelerations using multiband echo planar imaging at 3 Tesla

    OpenAIRE

    Xu, Junqian; Moeller, Steen; Auerbach, Edward J.; Strupp, John; Stephen M Smith; Feinberg, David A.; Yacoub, Essa; Uğurbil, Kâmil

    2013-01-01

    We evaluate residual aliasing among simultaneously excited and acquired slices in slice accelerated multiband (MB) echo planar imaging (EPI). No in-plane accelerations were used in order to maximize and evaluate achievable slice acceleration factors at 3 Tesla. We propose a novel leakage (L-) factor to quantify the effects of signal leakage between simultaneously acquired slices. With a standard 32-channel receiver coil at 3 Tesla, we demonstrate that slice acceleration factors of up to eight...

  7. Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the stability of brain-cortex ribosomes.

    Science.gov (United States)

    Datta, R K; Ghosh, J J

    1970-05-01

    1. During the action of mescaline sulphate on goat brain-cortex slices the ribosomal particles become susceptible to breakdown, releasing protein, RNA, acidsoluble nucleotides and ninhydrin-positive materials, resulting in loss of ribosomal enzyme activities. 2. Ribosomes of the mescaline-treated cortex slices undergo rapid degradation in the presence of trypsin and ribonuclease. 3. Mescaline does not alter the chemical and nucleotide compositions or the u.v.-absorption characteristics of ribosomal particles, however.

  8. Investigation of Synaptic Tagging/Capture and Cross-capture using Acute Hippocampal Slices from Rodents.

    Science.gov (United States)

    Shetty, Mahesh Shivarama; Sharma, Mahima; Hui, Neo Sin; Dasgupta, Ananya; Gopinadhan, Suma; Sajikumar, Sreedharan

    2015-01-01

    Synaptic tagging and capture (STC) and cross-tagging are two important mechanisms at cellular level that explain how synapse-specificity and associativity is achieved in neurons within a specific time frame. These long-term plasticity-related processes are the leading candidate models to study the basis of memory formation and persistence at the cellular level. Both STC and cross-tagging involve two serial processes: (1) setting of the synaptic tag as triggered by a specific pattern of stimulation, and (2) synaptic capture, whereby the synaptic tag interacts with newly synthesized plasticity-related proteins (PRPs). Much of the understanding about the concepts of STC and cross-tagging arises from the studies done in CA1 region of the hippocampus and because of the technical complexity many of the laboratories are still unable to study these processes. Experimental conditions for the preparation of hippocampal slices and the recording of stable late-LTP/LTD are extremely important to study synaptic tagging/cross-tagging. This video article describes the experimental procedures to study long-term plasticity processes such as STC and cross-tagging in the CA1 pyramidal neurons using stable, long-term field-potential recordings from acute hippocampal slices of rats. PMID:26381286

  9. [Pharmacological influences on the brain level and transport of GABA. II) Effect of various psychoactive drugs on brain level and uptake of GABA].

    Science.gov (United States)

    Gabana, M A; Varotto, M; Saladini, M; Zanchin, G; Battistin, L

    1981-04-30

    The effects of some psychoactive drugs on the level and uptake of GABA in the mouse brain was studied using well standardized procedures, mainely the silica-gel cromatography for determining the GABA content and the brain slices for measuring GABA uptake. It was found that levomepromazine, sulpiride, haloperidol and amytryptiline were without effects on the cerebral level of GABA; it was also found that these drugs do not influence the rates of uptake of GABA by mouse brain slices. Such results do indicate that the psychoactive drugs studied are without effects on the level and uptake of GABA in the brain. PMID:7272066

  10. Axisymmetric constant mean curvature slices in the Kerr spacetime

    International Nuclear Information System (INIS)

    Recently, there have been efforts to solve Einstein’s equation in the context of a conformal compactification of spacetime. Of particular importance in this regard are the so-called constant mean curvature (CMC) foliations, characterized by spatial hyperboloidal hypersurfaces with a constant extrinsic mean curvature K. However, although of interest for general spacetimes, CMC slices are known explicitly only for the spherically symmetric Schwarzschild metric. This work is devoted to numerically determining axisymmetric CMC slices within the Kerr solution. We construct such slices outside the black hole horizon through an appropriate coordinate transformation in which an unknown auxiliary function A is involved. The condition K = const throughout the slice leads to a nonlinear partial differential equation for the function A, which is solved with a pseudo-spectral method. The results exhibit exponential convergence, as is to be expected in a pseudo-spectral scheme for analytic solutions. As a by-product, we identify CMC slices of the Schwarzschild solution which are not spherically symmetric. (paper)

  11. Rapid and quantitative discrimination of tumour cells on tissue slices

    Science.gov (United States)

    Huang, Kai-Wen; Chieh, Jen-Jie; Liao, Shu-Hsien; Wei, Wen-Chun; Hsiao, Pei-Yi; Yang, Hong-Chang; Horng, Herng-Er

    2016-06-01

    After a needle biopsy, immunohistochemistry is generally used to stain tissue slices for clinically confirming tumours. Currently, tissue slices are immersed in a bioprobe-linked fluorescent reagent for several minutes, washed to remove the unbound reagent, and then observed using a fluorescence microscope. However, the observation must be performed by experienced pathologists, and producing a qualitative analysis is time consuming. Therefore, this study proposes a novel scanning superconducting quantum interference device biosusceptometry (SSB) method for avoiding these drawbacks. First, stain reagents were synthesised for the dual modalities of fluorescent and magnetic imaging by combining iron-oxide magnetic nanoparticles and the currently used fluorescent reagent. The reagent for the proposed approach was stained using the same procedure as that for the current fluorescent reagent, and tissue slices were rapidly imaged using the developed SSB for obtaining coregistered optical and magnetic images. Analysing the total intensity of magnetic spots in SSB images enables quantitatively determining the tumour cells of tissue slices. To confirm the magnetic imaging results, a traditional observation methodology entailing the use of a fluorescence microscope was also performed as the gold standard. This study determined high consistency between the fluorescent and magnetic spots in different regions of the tissue slices, demonstrating the feasibility of the proposed approach, which will benefit future clinical pathology.

  12. Design and evaluation of area-efficient and wide-range impedance analysis circuit for multichannel high-quality brain signal recording system

    Science.gov (United States)

    Iwagami, Takuma; Tani, Takaharu; Ito, Keita; Nishino, Satoru; Harashima, Takuya; Kino, Hisashi; Kiyoyama, Koji; Tanaka, Tetsu

    2016-04-01

    To enable chronic and stable neural recording, we have been developing an implantable multichannel neural recording system with impedance analysis functions. One of the important things for high-quality neural signal recording is to maintain well interfaces between recording electrodes and tissues. We have proposed an impedance analysis circuit with a very small circuit area, which is implemented in a multichannel neural recording and stimulating system. In this paper, we focused on the design of an impedance analysis circuit configuration and the evaluation of a minimal voltage measurement unit. The proposed circuit has a very small circuit area of 0.23 mm2 designed with 0.18 µm CMOS technology and can measure interface impedances between recording electrodes and tissues in ultrawide ranges from 100 Ω to 10 MΩ. In addition, we also successfully acquired interface impedances using the proposed circuit in agarose gel experiments.

  13. Estrogen receptor beta and 2-arachydonoylglycerol mediate the suppressive effects of estradiol on frequency of postsynaptic currents in gonadotropin-releasing hormone neurons of metestrous mice: an acute slice electrophysiological study

    Directory of Open Access Journals (Sweden)

    Flóra eBálint

    2016-03-01

    Full Text Available Gonadotropin-releasing hormone (GnRH neurons are controlled by 17β-estradiol (E2 contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM on GnRH neurons in acute brain slices obtained from metestrous GnRH-GFP mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachydonoylglycerol (2-AG signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs in GnRH neurons (49. 62±7.6% which effect was abolished by application of the ERα/β blocker Faslodex (1 µM. Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1 inverse agonist AM251 (1 µM and intracellularly applied endocannabinoid synthesis blocker THL (10 µM significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of TTX indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM also significantly decreased the frequency of miniature postsynaptic currents (mPSCs in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 µM indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM or the membrane-associated G protein-coupled estrogen receptor (GPR30 agonist G1 (10 pM had no significant effect on the frequency of mPSCs in these neurons. AM251 and THL significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These

  14. Automatic Circuit Extractor for HDL Description Using Program Slicing

    Institute of Scientific and Technical Information of China (English)

    Tun Li; Yang Guo; Si-Kun Li

    2004-01-01

    Design extraction and reduction have been extensively used in modern VLSI design process. The extracted and reduced design can be efficiently processed by various applications, such as formal verification,simulation, automatic test pattern generation (ATPG), etc. This paper presents a new circuit extraction method using program slicing technique, and develops an elegant theoretical basis based on program slicing for circuit extraction from Verilog description. The technique can obtain a chaining slice for given signals of interest. Compared with related researches, the main advantages of the method include that it is fine grain; it has no hardware description language (HDL) coding style limitation; it is precise and is capable of dealing with various Verilog constructions. The technique has been integrated with a commercial simulation environment and incorporated into a design process. The results of practical designs show the significant benefits of the approach.

  15. Fluid dynamic lateral slicing of high tensile strength carbon nanotubes.

    Science.gov (United States)

    Vimalanathan, Kasturi; Gascooke, Jason R; Suarez-Martinez, Irene; Marks, Nigel A; Kumari, Harshita; Garvey, Christopher J; Atwood, Jerry L; Lawrance, Warren D; Raston, Colin L

    2016-01-01

    Lateral slicing of micron length carbon nanotubes (CNTs) is effective on laser irradiation of the materials suspended within dynamic liquid thin films in a microfluidic vortex fluidic device (VFD). The method produces sliced CNTs with minimal defects in the absence of any chemical stabilizers, having broad length distributions centred at ca 190, 160 nm and 171 nm for single, double and multi walled CNTs respectively, as established using atomic force microscopy and supported by small angle neutron scattering solution data. Molecular dynamics simulations on a bent single walled carbon nanotube (SWCNT) with a radius of curvature of order 10 nm results in tearing across the tube upon heating, highlighting the role of shear forces which bend the tube forming strained bonds which are ruptured by the laser irradiation. CNT slicing occurs with the VFD operating in both the confined mode for a finite volume of liquid and continuous flow for scalability purposes. PMID:26965728

  16. Plastinated heart slices aid echocardiographic interpretation in the dog.

    Science.gov (United States)

    Gómez, Alejandro; Del Palacio, Josefa F; Latorre, Rafael; Henry, Robert W; Sarriá, Ricardo; Albors, Octavio López

    2012-01-01

    Our aim was to compare plastinated sections of the canine heart with corresponding two-dimensional (2D) echocardiographic images. Thirteen dog hearts were fixed by dilation and then processed by the S10 silicon plastination method (Biodur). Two dogs without evidence of cardiac disease were imaged using 2D echocardiography so as to obtain a complete series of the standard right and left parasternal images, which were compared with corresponding plastinated slices obtained by knife sectioning of the hearts. The plastinated slices revealed the internal anatomy of the heart with great detail and were particularly useful to display the spatial relationship between complex anatomic structures. The plastinated slices corresponded accurately with the echocardiographic images. Because of the dilation of the right heart during the fixation process, it was not possible to obtain plastinated specimens in ventricular systole. This paper may be a reference atlas for assisting 2D echocardiography interpretation. PMID:22092521

  17. Feature extraction from slice data for reverse engineering

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yingjie; LU Shangning

    2007-01-01

    A new approach to feature extraction for slice data points is presented. The reconstruction of objects is performed as follows. First, all contours in each slice are extracted by contour tracing algorithms. Then the data points on the contours are analyzed, and the curve segments of the contours are divided into three categories: straight lines, conic curves and B-spline curves. The curve fitting methods are applied for each curve segment to remove the unwanted points with pre-determined tolerance. Finally, the features, which consist of the object and connection relations among them, are founded by matching the corresponding contours in adjacent slices, and 3D models are reconstructed based on the features. The proposed approach has been implemented in OpenGL, and the feasibility of the proposed method has been verified by several cases.

  18. Fluid dynamic lateral slicing of high tensile strength carbon nanotubes

    Science.gov (United States)

    Vimalanathan, Kasturi; Gascooke, Jason R.; Suarez-Martinez, Irene; Marks, Nigel A.; Kumari, Harshita; Garvey, Christopher J.; Atwood, Jerry L.; Lawrance, Warren D.; Raston, Colin L.

    2016-03-01

    Lateral slicing of micron length carbon nanotubes (CNTs) is effective on laser irradiation of the materials suspended within dynamic liquid thin films in a microfluidic vortex fluidic device (VFD). The method produces sliced CNTs with minimal defects in the absence of any chemical stabilizers, having broad length distributions centred at ca 190, 160 nm and 171 nm for single, double and multi walled CNTs respectively, as established using atomic force microscopy and supported by small angle neutron scattering solution data. Molecular dynamics simulations on a bent single walled carbon nanotube (SWCNT) with a radius of curvature of order 10 nm results in tearing across the tube upon heating, highlighting the role of shear forces which bend the tube forming strained bonds which are ruptured by the laser irradiation. CNT slicing occurs with the VFD operating in both the confined mode for a finite volume of liquid and continuous flow for scalability purposes.

  19. Drying kinetics and colour change of lemon slices

    Science.gov (United States)

    Darvishi, Hosain; Khoshtaghaza, Mohammad H.; Minaei, Saeid

    2014-03-01

    The effect of microwave-convective heating on drying characteristics and colour change of lemon slices was investigated. The drying experiments were carried out at 180, 360, 540 and 720Wand at 22°C, with air velocity of 1ms-1. The values of effective moisture diffusivity were found to be in the range between 1.87 10-8 and 3.95 10-8 m2 s-1, and the activation energy was estimated to be 10.91 Wg-1. The drying data were fitted with ten mathematical models available in the literature. The model describing drying kinetics of lemon slices in the best way was found. The colour change of the dried lemon slices was analysed and considered as a quality index affecting the drying quality of the product. The values of lightness/darkness, yellowness/blueness and hue angle increased, while the value of redness/greenness decreased with increasing microwave power.

  20. 64-slice spiral CT in the diagnosis of Caroli disease

    International Nuclear Information System (INIS)

    Objective: To investigate the value of 64-slice spiral CT in the diagnosis of Caroli disease. Methods: 64-slice spiral CT of 15 patients with histologically proven Caroli disease was reviewed. Results: All cases were polycystic or multi-tubular hypodensities in the livers communicating with intrahepatic bile ducts. There was no contrast enhancement. The central dot sign was detected on 2 patients. Of 12 patients with type I disease, ancillary findings included multiple hemangiomas and small cysts in the liver (2), bile duct stones (4), pneumobilia (3), and cholangitis (1). Of the remaining 3 patients with type II disease, two had liver cirrhosis and the other cholangitis with periportal fibrosis. Conclusion: 64 slice spiral CT with multiplanar reconstruction allows clear depiction of cystic liver lesions and their relationship with intrahepatic bile ducts. It is valuable in the diagnosis of Caroli disease. (authors)

  1. Approach to combined-function magnets via symplectic slicing

    Science.gov (United States)

    Titze, M.

    2016-05-01

    In this article we describe how to obtain symplectic "slice" maps for combined-function magnets, by using a method of generating functions. A feature of this method is that one can use an unexpanded and unsplit Hamiltonian. From such a slice map we obtain a first-order map which is symplectic at the closed orbit. We also obtain a symplectic kick map. Both results were implemented into the widely used program MAD-X to regain, in particular, the twiss parameters for the sliced model of the Proton Synchrotron at CERN. In addition, we obtain recursion equations for symplectic maps of general time-dependent Hamiltonians, which might be useful even beyond the scope of accelerator physics.

  2. Color changes and acrylamide formation in fried potato slices

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Moyano, Pedro; Kaack, Karl;

    2005-01-01

    The objective of this work was to study the kinetics of browning during deep-fat frying of blanched and unblanched potato chips by using the dynamic method and to find a relationship between browning development and acrylamide formation. Prior to frying, potato slices were blanched in hot water...... at 85degreesC for 3.5 min. Unblanched slices were used as the control. Control and blanched potato slices (Panda variety, diameter: 37 mm, width: 2.2 mm) were fried at 120, 150 and 180degreesC until reaching moisture contents of similar to1.8% (total basis) and their acrylamide content and final color...... relationship with correlation coefficients greater than 90%. A first-order rate equation was used to model the kinetics of color change. In all case the Arrhenius activation energy decreases alongside with decreasing chip moisture content. Blanching reduced acrylamide formation in potato chips in similar to64...

  3. GEAR CRACK EARLY DIAGNOSIS USING BISPECTRUM DIAGONAL SLICE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A study of bispectral analysis in gearbox condition monitoring is presented.The theory of bispectrum and quadratic phase coupling (QPC) is first introduced, and then equations for computing bispectrum slices are obtained.To meet the needs of online monitoring, a simplified method of computing bispectrum diagonal slice is adopted.Industrial gearbox vibration signals measured from normal and tooth cracked conditions are analyzed using the above method.Experiments results indicate that bispectrum can effectively suppress the additive Gaussian noise and chracterize the QPC phenomenon.It is also shown that the 1-D bispectrum diagonal slice can capture the non-Gaussian and nonlinear feature of gearbox vibration when crack occurred, hence, this method can be employed to gearbox real time monitoring and early diagnosis.

  4. Fast parallel algorithm for slicing STL based on pipeline

    Science.gov (United States)

    Ma, Xulong; Lin, Feng; Yao, Bo

    2016-05-01

    In Additive Manufacturing field, the current researches of data processing mainly focus on a slicing process of large STL files or complicated CAD models. To improve the efficiency and reduce the slicing time, a parallel algorithm has great advantages. However, traditional algorithms can't make full use of multi-core CPU hardware resources. In the paper, a fast parallel algorithm is presented to speed up data processing. A pipeline mode is adopted to design the parallel algorithm. And the complexity of the pipeline algorithm is analyzed theoretically. To evaluate the performance of the new algorithm, effects of threads number and layers number are investigated by a serial of experiments. The experimental results show that the threads number and layers number are two remarkable factors to the speedup ratio. The tendency of speedup versus threads number reveals a positive relationship which greatly agrees with the Amdahl's law, and the tendency of speedup versus layers number also keeps a positive relationship agreeing with Gustafson's law. The new algorithm uses topological information to compute contours with a parallel method of speedup. Another parallel algorithm based on data parallel is used in experiments to show that pipeline parallel mode is more efficient. A case study at last shows a suspending performance of the new parallel algorithm. Compared with the serial slicing algorithm, the new pipeline parallel algorithm can make full use of the multi-core CPU hardware, accelerate the slicing process, and compared with the data parallel slicing algorithm, the new slicing algorithm in this paper adopts a pipeline parallel model, and a much higher speedup ratio and efficiency is achieved.

  5. Brain Basics

    Medline Plus

    Full Text Available ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  6. Brain Basics

    Science.gov (United States)

    ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  7. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  8. Dibucaine mitigates spreading depolarization in human neocortical slices and prevents acute dendritic injury in the ischemic rodent neocortex.

    Directory of Open Access Journals (Sweden)

    W Christopher Risher

    Full Text Available Spreading depolarizations that occur in patients with malignant stroke, subarachnoid/intracranial hemorrhage, and traumatic brain injury are known to facilitate neuronal damage in metabolically compromised brain tissue. The dramatic failure of brain ion homeostasis caused by propagating spreading depolarizations results in neuronal and astroglial swelling. In essence, swelling is the initial response and a sign of the acute neuronal injury that follows if energy deprivation is maintained. Choosing spreading depolarizations as a target for therapeutic intervention, we have used human brain slices and in vivo real-time two-photon laser scanning microscopy in the mouse neocortex to study potentially useful therapeutics against spreading depolarization-induced injury.We have shown that anoxic or terminal depolarization, a spreading depolarization wave ignited in the ischemic core where neurons cannot repolarize, can be evoked in human slices from pediatric brains during simulated ischemia induced by oxygen/glucose deprivation or by exposure to ouabain. Changes in light transmittance (LT tracked terminal depolarization in time and space. Though spreading depolarizations are notoriously difficult to block, terminal depolarization onset was delayed by dibucaine, a local amide anesthetic and sodium channel blocker. Remarkably, the occurrence of ouabain-induced terminal depolarization was delayed at a concentration of 1 µM that preserves synaptic function. Moreover, in vivo two-photon imaging in the penumbra revealed that, though spreading depolarizations did still occur, spreading depolarization-induced dendritic injury was inhibited by dibucaine administered intravenously at 2.5 mg/kg in a mouse stroke model.Dibucaine mitigated the effects of spreading depolarization at a concentration that could be well-tolerated therapeutically. Hence, dibucaine is a promising candidate to protect the brain from ischemic injury with an approach that does not rely on

  9. Verification of Software Product Lines with Delta-Oriented Slicing

    Science.gov (United States)

    Bruns, Daniel; Klebanov, Vladimir; Schaefer, Ina

    Software product line (SPL) engineering is a well-known approach to develop industry-size adaptable software systems. SPL are often used in domains where high-quality software is desirable; the overwhelming product diversity, however, remains a challenge for assuring correctness. In this paper, we present delta-oriented slicing, an approach to reduce the deductive verification effort across an SPL where individual products are Java programs and their relations are described by deltas. On the specification side, we extend the delta language to deal with formal specifications. On the verification side, we combine proof slicing and similarity-guided proof reuse to ease the verification process.

  10. Preparing polished crystal slices with high precision orientation

    DEFF Research Database (Denmark)

    Mathiesen, S. Ipsen; Gerward, Leif; Pedersen, O.

    1974-01-01

    A polishing procedure is described which utilizes a high precision Laue technique for crystal orientation. Crystal slices with their final polished surfaces parallel to a crystallographic plane within 0.02° can be prepared. ©1974 The American Institute of Physics......A polishing procedure is described which utilizes a high precision Laue technique for crystal orientation. Crystal slices with their final polished surfaces parallel to a crystallographic plane within 0.02° can be prepared. ©1974 The American Institute of Physics...

  11. Single-slice mapping of ultrashort T(2).

    Science.gov (United States)

    Kirsch, Stefan; Schad, Lothar R

    2011-05-01

    In this communication we present a method for single-slice mapping of ultrashort transverse relaxation times T(2). The RF pulse sequence consists of a spin echo preparation of the magnetization followed by slice-selective ultrashort echo time (UTE) imaging with radial k-space sampling. In order to keep the minimum echo time as small as possible, avoid out-of-slice contamination and signal contamination due to unwanted echoes, the implemented pulse sequence employs a slice-selective 180° RF refocusing pulse and a 4-step phase cycle. The slice overlap of the two slice-selective RF pulses was investigated. An acceptable Gaussian slice profile could be achieved by adjusting the strength of the two slice-selection gradients. The method was tested on a short T(2) phantom consisting of an arrangement of a roll of adhesive tape, an eraser, a piece of modeling dough made of Plasticine®, and a 10% w/w agar gel. The T(2) measurements on the phantom revealed exponential signal decays for all samples with T(2)(adhesive tape)=(0.5 ± 0.1)ms, T(2)(eraser)=(2.33 ± 0.07)ms, T(2)(Plasticine®)=(2.8 ± 0.06)ms, and T(2)(10%agar)=(9.5 ± 0.83)ms. The T(2) values obtained by the mapping method show good agreement with the T(2) values obtained by a non-selective T(2) measurement. For all samples, except the adhesive tape, the effective transverse relaxation time T(2)(∗) was significantly shorter than T(2). Depending on the scanner hardware the presented method allows mapping of T(2) down to a few hundreds of microseconds. Besides investigating material samples, the presented method can be used to study the rapidly decaying MR-signal from biological tissue (e.g.: bone, cartilage, and tendon) and quadrupolar nuclei (e.g.: (23)Na, (35)Cl, and (17)O). PMID:21353799

  12. Single-slice mapping of ultrashort T 2

    Science.gov (United States)

    Kirsch, Stefan; Schad, Lothar R.

    2011-05-01

    In this communication we present a method for single-slice mapping of ultrashort transverse relaxation times T2. The RF pulse sequence consists of a spin echo preparation of the magnetization followed by slice-selective ultrashort echo time (UTE) imaging with radial k-space sampling. In order to keep the minimum echo time as small as possible, avoid out-of-slice contamination and signal contamination due to unwanted echoes, the implemented pulse sequence employs a slice-selective 180° RF refocusing pulse and a 4-step phase cycle. The slice overlap of the two slice-selective RF pulses was investigated. An acceptable Gaussian slice profile could be achieved by adjusting the strength of the two slice-selection gradients. The method was tested on a short T2 phantom consisting of an arrangement of a roll of adhesive tape, an eraser, a piece of modeling dough made of Plasticine®, and a 10% w/w agar gel. The T2 measurements on the phantom revealed exponential signal decays for all samples with T2(adhesive tape) = (0.5 ± 0.1) ms, T2(eraser) = (2.33 ± 0.07) ms, T2(Plasticine®) = (2.8 ± 0.06) ms, and T2(10% agar) = (9.5 ± 0.83) ms. The T2 values obtained by the mapping method show good agreement with the T2 values obtained by a non-selective T2 measurement. For all samples, except the adhesive tape, the effective transverse relaxation time T2∗ was significantly shorter than T2. Depending on the scanner hardware the presented method allows mapping of T2 down to a few hundreds of microseconds. Besides investigating material samples, the presented method can be used to study the rapidly decaying MR-signal from biological tissue (e.g.: bone, cartilage, and tendon) and quadrupolar nuclei (e.g.: 23Na, 35Cl, and 17O).

  13. Single slice US-MRI registration for neurosurgical MRI-guided US

    Science.gov (United States)

    Pardasani, Utsav; Baxter, John S. H.; Peters, Terry M.; Khan, Ali R.

    2016-03-01

    Image-based ultrasound to magnetic resonance image (US-MRI) registration can be an invaluable tool in image-guided neuronavigation systems. State-of-the-art commercial and research systems utilize image-based registration to assist in functions such as brain-shift correction, image fusion, and probe calibration. Since traditional US-MRI registration techniques use reconstructed US volumes or a series of tracked US slices, the functionality of this approach can be compromised by the limitations of optical or magnetic tracking systems in the neurosurgical operating room. These drawbacks include ergonomic issues, line-of-sight/magnetic interference, and maintenance of the sterile field. For those seeking a US vendor-agnostic system, these issues are compounded with the challenge of instrumenting the probe without permanent modification and calibrating the probe face to the tracking tool. To address these challenges, this paper explores the feasibility of a real-time US-MRI volume registration in a small virtual craniotomy site using a single slice. We employ the Linear Correlation of Linear Combination (LC2) similarity metric in its patch-based form on data from MNI's Brain Images for Tumour Evaluation (BITE) dataset as a PyCUDA enabled Python module in Slicer. By retaining the original orientation information, we are able to improve on the poses using this approach. To further assist the challenge of US-MRI registration, we also present the BOXLC2 metric which demonstrates a speed improvement to LC2, while retaining a similar accuracy in this context.

  14. Phosphatase inhibitors remove the run-down of γ-aminobutyric acid type A receptors in the human epileptic brain

    Science.gov (United States)

    Palma, E.; Ragozzino, D. A.; Di Angelantonio, S.; Spinelli, G.; Trettel, F.; Martinez-Torres, A.; Torchia, G.; Arcella, A.; Di Gennaro, G.; Quarato, P. P.; Esposito, V.; Cantore, G.; Miledi, R.; Eusebi, F.

    2004-01-01

    The properties of γ-aminobutyric acid (GABA) type A receptors (GABAA receptors) microtransplanted from the human epileptic brain to the plasma membrane of Xenopus oocytes were compared with those recorded directly from neurons, or glial cells, in human brains slices. Cell membranes isolated from brain specimens, surgically obtained from six patients afflicted with drug-resistant temporal lobe epilepsy (TLE) were injected into frog oocytes. Within a few hours, these oocytes acquired GABAA receptors that generated GABA currents with an unusual run-down, which was inhibited by orthovanadate and okadaic acid. In contrast, receptors derived from membranes of a nonepileptic hippocampal uncus, membranes from mouse brain, or recombinant rat α1β2γ2-GABA receptors exhibited a much less pronounced GABA-current run-down. Moreover, the GABAA receptors of pyramidal neurons in temporal neocortex slices from the same six epileptic patients exhibited a stronger run-down than the receptors of rat pyramidal neurons. Interestingly, the GABAA receptors of neighboring glial cells remained substantially stable after repetitive activation. Therefore, the excessive GABA-current run-down observed in the membrane-injected oocytes recapitulates essentially what occurs in neurons, rather than in glial cells. Quantitative RT-PCR analyses from the same TLE neocortex specimens revealed that GABAA-receptor β1, β2, β3, and γ2 subunit mRNAs were significantly overexpressed (8- to 33-fold) compared with control autopsy tissues. Our results suggest that an abnormal GABA-receptor subunit transcription in the TLE brain leads to the expression of run-down-enhanced GABAA receptors. Blockage of phosphatases stabilizes the TLE GABAA receptors and strengthens GABAergic inhibition. It may be that this process can be targeted to develop new treatments for intractable epilepsy. PMID:15218107

  15. Rabbit cerebellar slice analysis of long-term depression and its role in classical conditioning.

    Science.gov (United States)

    Schreurs, B G; Alkon, D L

    1993-12-24

    Cerebellar long-term depression (LTD) has been proposed as a mechanism underlying classical conditioning of the rabbit nictitating membrane/eyelid response (NMR). However, LTD has only been obtained reliably when (1) cerebellar slices are bathed in GABA antagonists which abolish disynaptic inhibitory post synaptic potentials, and (2) the temporal sequence of stimulation used in slice or intact preparations is the opposite of that used in classical conditioning. Based on intradendritic Purkinje cell recordings obtained from rabbit cerebellar slices, we report that stimulation of climbing fibers and then parallel fibers in the presence of the GABA antagonist, bicuculline, produced significant depression of parallel fiber excitatory post synaptic potential (epsp) amplitude that continued to increase for at least 20 min after stimulation. However, application of the same stimulation protocol without GABA antagonists produced a brief depression of parallel fiber epsps that disappeared within minutes. Activation of parallel fibers and then climbing fibers in an order opposite to the LTD-producing sequence (i.e. a classical conditioning-like order) produced a brief depression that dissipated quickly. Stimulation of parallel fibers alone produced a small, slowly developing potentiation, but stimulation of parallel fibers during depolarization-induced local dendritic calcium spikes produced significant depression almost immediately which then declined slowly to more modest levels. Finally, stimulation of parallel fibers at frequencies used in in vivo parallel fiber-climbing fiber stimulation experiments (e.g. 100 Hz) produced an immediate and profound long-lasting epsp depression. The depression occurred, however, whether parallel and climbing fibers were stimulated separately (unpaired) or in a classical conditioning-like protocol (paired) where parallel fiber stimulation coterminated with climbing fiber stimulation (10 Hz).(ABSTRACT TRUNCATED AT 250 WORDS)

  16. "The Most Famous Brain in the World" Performance and Pedagogy on an Amnesiac's Brain

    Science.gov (United States)

    Sweaney, Katherine W.

    2012-01-01

    Project H.M. was just the sort of thing one might expect the Internet to latch onto: it was a live streaming video of a frozen human brain being slowly sliced apart. Users who clicked the link on Twitter or Facebook between the 2nd and 4th of December 2009 were immediately confronted with a close-up shot of the brain's interior, which was…

  17. Automated detection of hypoglycemia-induced EEG changes recorded by subcutaneous electrodes in subjects with type 1 diabetes--the brain as a biosensor

    DEFF Research Database (Denmark)

    Juhl, Claus B.; Højlund, Kurt; Elsborg, Rasmus;

    2010-01-01

    Hypoglycemia unawareness is a common condition associated with increased risk of severe hypoglycemia. We test the hypothesis that specific changes in the electroencephalogram (EEG) during hypoglycemia can be recorded by subcutaneous electrodes and processed by a general mathematical algorithm, and...

  18. Blanching, salting and sun drying of different pumpkin fruit slices.

    Science.gov (United States)

    Workneh, T S; Zinash, A; Woldetsadik, K

    2014-11-01

    The study was aimed at assessing the quality of pumpkin (Cucuribita Spp.) slices that were subjected to pre-drying treatments and drying using two drying methods (uncontrolled sun and oven) fruit accessions. Pre-drying had significant (P ≤ 0.05) effect on the quality of dried pumpkin slices. 10 % salt solution dipped pumpkin fruit slices had good chemical quality. The two-way interaction between drying methods and pre-drying treatments had significant (P ≤ 0.05) effect on chemical qualities. Pumpkin subjected to salt solution dipping treatment and oven dried had higher chemical concentrations. Among the pumpkin fruit accessions, pumpkin accession 8007 had the superior TSS, total sugar and sugar to acid ratio after drying. Among the three pre-drying treatment, salt solution dipping treatment had significant (P ≤ 0.05) effect and the most efficient pre-drying treatment to retain the quality of dried pumpkin fruits without significant chemical quality deterioration. Salt dipping treatment combined with low temperature (60 °C) oven air circulation drying is recommended to maintain quality of dried pumpkin slices. However, since direct sun drying needs extended drying time due to fluctuation in temperature, it is recommended to develop or select best successful solar dryer for use in combination with pre-drying salt dipping or blanching treatments.

  19. Steamed Sliced Pork with Dried Mustard Cabbage (Meigancai Kourou)

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    500 grams pork with skin75 grams dried mustard cabbage10 grams Shaoxing wine50 grams sugar100 grams soy sauce2 grams salt5 grams spring onions5 grams ginger500 grams clear stockClean the pork, soak the dried mustard cabbage until soft, and clean and slice the spring onion and ginger.Braise the pork in a wok, then

  20. Mathematical modeling on vacuum drying of Zizyphus jujuba Miller slices.

    Science.gov (United States)

    Lee, Jun Ho; Zuo, Li

    2013-02-01

    The thin-layer vacuum drying behavior of Zizyphus jujuba Miller slices was experimentally investigated at the temperature of 50, 60, and 70 °C and the mathematical models were used to fit the thin-layer vacuum drying of Z. jujuba slices. The increase in drying air temperature resulted in a decrease in drying time. The drying rate was found to increase with temperature, thereby reducing the total drying time. It was found that Z. jujuba slices with thickness of 4 mm would be dried up to 0.08 kg water/kg dry matter in the range of 180-600 min in the vacuum dryer at the studied temperature range from 70 to 50 °C. The Midilli et al. model was selected as the most appropriate model to describe the thin-layer drying of Z. jujuba slices. The diffusivity coefficient increased linearly over the temperature range from 1.47 × 10(-10) to 3.27 × 10(-10) m(2)/s, as obtained using Fick's second law. The temperature dependence of the effective diffusivity coefficient followed an Arrhenius-type relationship. The activation energy for the moisture diffusion was determined to be 36.76 kJ/mol. PMID:24425895

  1. Slicing Recognition of Aircraft Integral Panel Generalized Pocket

    Institute of Scientific and Technical Information of China (English)

    Yu Fangfang; Du Baorui; Ren Wenjie; Zheng Guolei; Chu Hongzhen

    2008-01-01

    To automatically obtain a machining area in numerical control (NC) programming, a data model of generalized pocket is estab-lished by analyzing aireraft integral panel characteristics, and a feature recognition approach is proposed. First, by reference to the prao- tieal slice-machining process of an aircraft integral panel, both the part and the blank are sliced in the Z-axis direction; hence a feature profile is created acceding to the slicing planes and the contours are formed by the intersection of the slicing planes with the part and its blanK. Second, the auxiliary features of the generalized pocket are also determined based on the face type and the position, to correct the profile of the pocket. Finally, the generalized pocket feature relationship tree is constructed by matching the vertical relationships among the features. Machining feature information produced by using this method can be directly used to calculate the cutter path. The validity and practicability of the method is verified by NC programming for aircraft panels.

  2. Thin slice impressions : How advertising evaluation depends on exposure duration

    NARCIS (Netherlands)

    Pieters, Rik; Elsen, M.; Wedel, M.

    2016-01-01

    The duration of exposures to advertising is often brief. Then, consumers can only obtain “thin slices” of information from the ads, such as which product and brand are being promoted. This research is the first to examine the influence that such thin slices of information have on ad and brand evalua

  3. TSLV: Time-Slice-Based Location Verification for VANET

    Institute of Scientific and Technical Information of China (English)

    Xue Xiaoping; Liu Mingyang; Lin Nizhong; Zhang Yuehao

    2011-01-01

    Position-spoofing-based attacks seriously threaten the security of Vehicular Ad Hoc Network (VANET).An effective solution to detect position spoofing is location verification.However,since vehicles move fast and the topology changes quickly in VANET,the static location verification method in Wireless Sensor Network (WSN) is not suitable for VANET.Taking into account the dynamic changing topology of VANET and collusion,we propose a Time-Slice-based Location Verification scheme,named TSLV,to resist position spoofing in VANET.Specifically,TSLV transforms the dynamic topology into static topology by time slice and each time slice corresponds to a verification process.The verifier can implement location verification for the corresponding prover.During the verification process,the verifier first filters out vehicles which provide unreasonably claimed locations,and then uses the Mean Square Error (MSE)-based cluster approach to separate the consistent vehicles by time slice,and uses the consistent set for its verification.In addition,security analysis and simulation show that TSLV can defend against the collusion attack effectively.

  4. Evaluation of fibrosis in precision-cut tissue slices

    NARCIS (Netherlands)

    Westra, I. M.; Pham, B. T.; Groothuis, G. M. M.; Olinga, P.

    2013-01-01

    1. In this review, the use of precision-cut tissue slices (PCTS) of the liver, kidney, lung and intestine in fibrosis research are evaluated and future possibilities are discussed. 2. In vivo models or techniques that are applicabless to be investigated in PCTS are discussed. 3. It is concluded that

  5. Blanching, salting and sun drying of different pumpkin fruit slices.

    Science.gov (United States)

    Workneh, T S; Zinash, A; Woldetsadik, K

    2014-11-01

    The study was aimed at assessing the quality of pumpkin (Cucuribita Spp.) slices that were subjected to pre-drying treatments and drying using two drying methods (uncontrolled sun and oven) fruit accessions. Pre-drying had significant (P ≤ 0.05) effect on the quality of dried pumpkin slices. 10 % salt solution dipped pumpkin fruit slices had good chemical quality. The two-way interaction between drying methods and pre-drying treatments had significant (P ≤ 0.05) effect on chemical qualities. Pumpkin subjected to salt solution dipping treatment and oven dried had higher chemical concentrations. Among the pumpkin fruit accessions, pumpkin accession 8007 had the superior TSS, total sugar and sugar to acid ratio after drying. Among the three pre-drying treatment, salt solution dipping treatment had significant (P ≤ 0.05) effect and the most efficient pre-drying treatment to retain the quality of dried pumpkin fruits without significant chemical quality deterioration. Salt dipping treatment combined with low temperature (60 °C) oven air circulation drying is recommended to maintain quality of dried pumpkin slices. However, since direct sun drying needs extended drying time due to fluctuation in temperature, it is recommended to develop or select best successful solar dryer for use in combination with pre-drying salt dipping or blanching treatments. PMID:26396303

  6. Comparative study of the sectional slice of the anterior commissure and the internal capsule with its MRI images

    Institute of Scientific and Technical Information of China (English)

    WANG Dandan; MA Wenyi; Zhang Xiaoyang; YUAN Lixiang; YUAN Wu; LI Yunsheng

    2015-01-01

    Objective:The brain of 100 normal persons were performed MRI scan and image analysis. 12 adult female brain specimens fixed by formalin, were made into the thickness of 0. 5mm by celloidin embedding technique. We analyzed the anatomical position of the relationship about the anterior limb of internal capsule and the anterior commissure in eollodion-embedded plans, and then compared with the brain MRI of normal people. We also further compared the statistical differences of the internal capsule’ s volume. This research aimed to pro-vide a reliable sectional anatomic basis for the study of the central nervous system and deep brain stimulation to treat the mental neurological diseases. Results:1. Continous observation of celloid in brain slices horizontal section:Approximately 130 slices of each specimen, from the parietal lobe,the internal capsule was the typical structure"><" on the level of about 35 mm . On the level of about 41mm, the anterior commissure was"arc" through the bot-tom head of the caudate nucleus connecting the bilateral anterior limb, which located between the caudate nucleus and the lentiform nucleus. The posterior limb of internal capsule situated between the dorsal thalamus and the lenti-form nucleus on the level of about 46 mm. Coronal section:about 150 slices of per specimen, from the former lat-eral ventricle horn back,on the level of about 16 mm the anterior commissure was "arch" connecting the anterior limb. About 28 mm dimension, the interior capsule fore limb located between the caudate nucleus and the puta-men, the posterior limb of internal capsule located between the globus pallidus and the dorsal thalamus, extending down to the cerebral peduncle. Sagittal section:about 180 slices of per specimen, from the outside to the inside at the beginning of the temporal lobe, the corona radia taextends between the putamen and dorsal thalamus, and then formsthe posterior limb of the internal capsule at the level of about 21 mm. About 25 mm level

  7. A new algorithm of brain volume contours segmentation

    Institute of Scientific and Technical Information of China (English)

    吴建明; 施鹏飞

    2003-01-01

    This paper explores brain CT slices segmentation technique and some related problems, including contours segmentation algorithms, edge detector, algorithm evaluation and experimental results. This article describes a method for contour-based segmentation of anatomical structures in 3D medical data sets. With this method, the user manually traces one or more 2D contours of an anatomical structure of interest on parallel planes arbitrarily cutting the data set. The experimental results showes the segmentation based on 3D brain volume and 2D CT slices. The main creative contributions in this paper are: (1) contours segmentation algorithm; (2) edge detector; (3) algorithm evaluation.

  8. Brain herniation

    Science.gov (United States)

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  9. A primary study of polygraph recording from patients with traumatic brain injury%多普描记仪在脑外伤患者中的测试初探

    Institute of Scientific and Technical Information of China (English)

    李钢琴; 吕连辉; 胡泽卿

    2012-01-01

    Objective To investigate the responses of the patient with traumatic brain injury in the polygraph test, therefore to provide reference data to the field. Methods 30 patients with traumatic brain injury and 30 normal volunteers were tested by polygraph with Stimulation Test (STIM) .recording responses of the skin conductance,respiration and finger pulse. Results In patients with traumatic brain injury,the overall rate of accuracy was 53%. In the normal people ,the overall rate of accuracy was 80%. There was significant difference between the two groups (P < 0. 05). Conclusions The accuracy would be lower when the patient with traumatic brain injury was tested by polygraph.%目的 研究脑外伤患者应用多普描记仪的反应,为多普描记仪应用于脑外伤患者提供部分实验数据.方法 30例司法鉴定的脑外伤患者为研究对象,30例正常人作为对照,用多普描记仪对两组进行猜数测试,记录两组受试对象的皮肤电、呼吸和指尖脉搏的变化.结果 实验组的综合准确率为53%,对照组的综合准确率为80%,统计分析发现两组差异有统计学意义(P<0.05).结论 多普描记仪用于脑外伤患者时,其准确率较低.

  10. Distribution of melatonin receptor in human fetal brain

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-quan; SHAO Fu-yuan; ZHAO Ying; LIU Zhi-min

    2001-01-01

    Objective: To study the distribution of 2 kinds of melatonin receptor subtypes (mtl and MT2) in human fetal brain. Methods: The fetal brain tissues were sliced and the distribution ofmelatonin receptors in human fetal brain were detected using immunohistochemistry and in situ hybridization. Results: Melatonin receptor mtl existed in the cerebellun and hypothalamus, melatonin receptor MT2 exists in hypothalamus, occipital and medulla. Conclusion: Two kinds of melatonin receptors, mtl and MT2 exist in the membrane and cytosol of brain cells, indicating that human fetal brain is a target organ of melatonin.

  11. Effect of simultaneous infrared dry-blanching and dehydration on quality characteristics of carrot slices

    Science.gov (United States)

    This study investigated the effects of various processing parameters on carrot slices exposed to infrared (IR) radiation heating for achieving simultaneous infrared dry-blanching and dehydration (SIRDBD). The investigated parameters were product surface temperature, slice thickness and processing ti...

  12. Metabolic Brain-Computer Interfaces

    OpenAIRE

    Sitaram, Ranganatha

    2010-01-01

    Brain-Computer Interfaces (BCI) utilise neurophysiological signals originating in the brain to activate or deactivate external devices or computers (Donoghue 2002; Wolpaw, Birbaumer et al. 2002; Nicolelis 2003; Birbaumer and Cohen 2007). The neuronal signals can be recorded from inside the brain (invasive BCIs) or outside (non-invasive BCIs) of the brain. Most BCIs developed so far have used operant training of direct neuroelectric responses, Electroencephalography (EEG) waves, event-related ...

  13. Whole-brain perfusion imaging and angiography performed with 256-slice CTin evaluation of cerebrovascular reserve capacity in unilateral carotid artery stenosis%256层CT全脑灌注成像联合CTA评估单侧颈动脉狭窄的脑血管储备能力的价值

    Institute of Scientific and Technical Information of China (English)

    唐健; 常军; 侯海燕; 姜旭栋; 堵红群; 姜建威

    2012-01-01

    Objective To assess the value of combination of whole-brain perfusion imaging and CTA in evaluating cerebrovascular reserve capacity in unilateral carotid artery stenosis. Methods Twenty-seven patients with unilateral carotid artery stenosis of ≥50% were divided into 2 groups according to CTA results: carotid moderate stenosis groupfcarotid stenosis of 50%-69%, group A) and carotid severe stenosis or occlusion group(carotid stenosis of ≥70% , group B). The relative cerebral blood volume(rCBV) , the relative cerebral blood folw(rCBF) , the difference in mean transit time(dMTT) and the difference in time to peak(dTTP) in bilateral temporal white matter and gray matter supplied by middle cerebral artery were measured and calculated. CTA was used to assess the configuration of the circle of Willis and if primary collaterals were patent. Differences in perfusion parameters between group A and group B, and between patients with patent primary collaterals or not were determined by using one way ANOVA test. Results There were statistical differences in rCBV, rCBF, dMTT and dTTP between two groups in white matter. Statistical difference of dMTT and dTTP was found between two groups in gray matter. There was significant increase in dTTP in the group B of the patients without patent primary collaterals. Conclusion Combined whole-brain perfusion imaging and CTA is a good way to evaluate cerebrovascular reserve capacity in unilateral carotid artery stenosis, and to provide a reliable method for choice of clinic treatments.%目的 探讨256层CT全脑灌注成像联合CTA评估单侧颈动脉狭窄的脑血管储备能力的价值.方法 单侧颈动脉狭窄≥50%的患者27例,根据CTA结果 按颈动脉狭窄程度划分为第一组中度狭窄组(血管阻塞50%~69%)和第二组重度狭窄或闭塞组(血管阻塞≥70%).测量并计算2组大脑中动脉供血区的白质和灰质的相对脑血容量(relative cerebral blood volume,r

  14. An optogenetics- and imaging-assisted simultaneous multiple patch-clamp recording system for decoding complex neural circuits.

    Science.gov (United States)

    Wang, Guangfu; Wyskiel, Daniel R; Yang, Weiguo; Wang, Yiqing; Milbern, Lana C; Lalanne, Txomin; Jiang, Xiaolong; Shen, Ying; Sun, Qian-Quan; Zhu, J Julius

    2015-03-01

    Deciphering neuronal circuitry is central to understanding brain function and dysfunction, yet it remains a daunting task. To facilitate the dissection of neuronal circuits, a process requiring functional analysis of synaptic connections and morphological identification of interconnected neurons, we present here a method for stable simultaneous octuple patch-clamp recordings. This method allows physiological analysis of synaptic interconnections among 4-8 simultaneously recorded neurons and/or 10-30 sequentially recorded neurons, and it allows anatomical identification of >85% of recorded interneurons and >99% of recorded principal neurons. We describe how to apply the method to rodent tissue slices; however, it can be used on other model organisms. We also describe the latest refinements and optimizations of mechanics, electronics, optics and software programs that are central to the realization of a combined single- and two-photon microscopy-based, optogenetics- and imaging-assisted, stable, simultaneous quadruple-viguple patch-clamp recording system. Setting up the system, from the beginning of instrument assembly and software installation to full operation, can be completed in 3-4 d.

  15. Brain Extraction and Fuzzy Tissue Segmentation in Cerebral 2D T1-Weigthed Magnetic Resonance Images

    OpenAIRE

    Bouchaib Cherradi; Omar Bouattane; Mohamed Youssfi; Abdelhadi Raihani

    2011-01-01

    In medical imaging, accurate segmentation of brain MR images is of interest for many brain manipulations. In this paper, we present a method for brain Extraction and tissues classification. An application of this method to the segmentation of simulated MRI cerebral images in three clusters will be made. The studied method is composed with different stages, first Brain Extraction from T1-weighted 2D MRI slices (TMBE) is performed as pre-processing procedure, then Histogram based centroids init...

  16. Role of Nitric Oxide and Nitric Oxide Synthases in Ischemia-reperfusion Injury in Rat Organotypic Hippocampus Slice

    Institute of Scientific and Technical Information of China (English)

    MENG Xianfang; SHI Jing; LIU Xiaochun; ZHANG Jing; SUN Ning

    2005-01-01

    To investigate the effects of ischemia-reperfusion on the levels of nitric oxide and nitric oxide synthase isoforms (nNOS and iNOS), rat organotypic hippocampus slice were cultured in vitro and subjected to ischemia by oxygen glucose deprivation (OGD) for 30 min and then placed in the normal culture condition. The ischemia-reperfusion produced a time-dependent increase in nitrite levels in the culture medium. Reverse transcriptional-polymerase chain reaction showed augmented levels of mRNA for both nNOS and iNOS when compared with control at 12 h and remained increase at 36 h after OGD (P<0.05). The protein levels of both nitric oxide synthase isoforms increased significantly as determined by Western Blot. OGD also caused neurotoxicity in this model as revealed by the elevated lactate dehydrogenase (LDH) efflux into the incubation solution. The results suggest that organotypic hippocampus slice is a useful model in studying ischemia-reperfusion brain injury. NO and NOS may play a critical role in the ischemia-reperfusion brain damage in vitro.

  17. Reduction of acrylamide formation in potato slices during frying

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Kaack, K.; Granby, Kit

    2004-01-01

    and 40 min; 90degreesC for 2 and 9 min); (iii) immersed in citric acid solutions of different concentrations (10 and 20 g/l) for half an hour. Glucose and asparagine concentration was determined in potato slices before frying, whereas acrylamide content was determined in the resultant fried potato chips...... on average 76% and 68% of the glucose and asparagine content compared to the control. Potato slices blanched at 50degreesC for 70 min surprisingly had a very low acrylamide content (28 mum/kg) even when they were fried at 190degreesC. Potato immersion in citric acid solutions of 10 and 20 g/l reduced...

  18. Effect of Blanching on Structural Quality of Dried Potato Slices.

    Science.gov (United States)

    Maté; Quartaert; Meerdink; van't Riet K

    1998-02-16

    Mechanical properties of potato slices were monitored during blanching, as indicators of structural changes. As expected, blanching resulted in weakening of potato structure. Gelatinization, which occurred during the first 2 min, did not promote an immediate weakening of the potato tissue. More than 80% of the changes in mechanical properties occurred during the first 30 min of blanching. Potato slices blanched for 2 and 30 min as well as unblanched ones were dried in a convective air drier at 48 degrees C. Bulk and true density, porosity, and shrinkage were monitored with time. Blanched potatoes resulted in a significantly more compact, less porous product with lower effective water diffusivity than unblanched potatoes. The results indicated that changes that occurred during the first 2 min of blanching had a much greater influence on structural quality of dried potatoes than changes that occurred from 2 to 30 min of blanching.

  19. Authentication and self-correction in sequential MRI slices.

    Science.gov (United States)

    Fotopoulos, Vassilis; Stavrinou, Maria L; Skodras, Athanassios N

    2011-10-01

    One of the new challenges of Information Technology in the medical world is the protection and authentication of a variety of digital medical files, datasets, and images. In this work, the ability of magnetic resonance imaging (MRI) slice sequences to hide digital data is investigated and more specifically the case that the hidden data are the regions of interest (ROI) of the MRI slices. The regions of non-interest (RONI) are used as cover. The hiding capacity of the whole sequence is taken into account. Any ROI-targeted tampering attempt can be detected, and the original image can be self-restored (under certain conditions) by extracting the ROI from the RONI.

  20. Penentuan Nilai Noise Berdasarkan Slice Thickness Pada Citra CT Scan

    OpenAIRE

    Sihombing, Hediana

    2015-01-01

    Noise measurements have been carried out with changes in thick slices CT Scan image by selecting the ROI on a water phantom objects. The method used in the measurement of noise values ranging from 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm and eksposi factor of 100 kV and 500 mAs. The results obtained are 6.32 HU; 5:14 HU; 3.86 HU; HU 3:48; HU 3:14; 2.94 HU; 2.78 HU; 2.52 HU; HU HU 2:44 and 2:38. The thicker slices diminishing the noise then the resulting CT images wer...

  1. Alternative oxidase expression in aged potato tuber slices

    Energy Technology Data Exchange (ETDEWEB)

    Hiser, C.; Herdies, L.; McIntosh, L. (Michigan State Univ., East Lansing (USA))

    1989-04-01

    Higher plant mitochondria posses a cyanide-resistant, hydroxamate-sensitive alternative pathway of electron transport that does not conserve energy. Aging of potato tuber slices for 24 hours leads to the development of an alternative pathway capacity. We have shown that a monoclonal antibody raised against the alternative pathway terminal oxidase of Sauromatum guttatum crossreacts with a protein of similar size in aged potato slice mitochondria. This protein was partially purified and characterized by two-dimensional gel electrophoresis, and its relative levels parallel the rise in cyanide-resistant respiration. We are using a putative clone of the S. guttatum alternative oxidase gene to isolate the equivalent gene from potato and to examine its expression.

  2. Microbiological quality of sliced and block mozzarella cheese

    Directory of Open Access Journals (Sweden)

    Mariana Fontanetti Marinheiro

    2015-06-01

    Full Text Available The aim of this study was to verify the microbiological quality of mozzarella cheese sold in retail markets of Pelotas, Rio Grande do Sul, Brazil. Forty samples of mozzarella cheese were analyzed, comprising 20 samples of block cheese and 20 of sliced cheese. The cheese samples were analyzed for thermotolerant coliform counts and coagulase positive staphylococci counts, and presence of Salmonella spp and Listeria monocytogenes. The percentage of 12,5% and 5% of the sliced and block cheese samples analyzed, respectively, exceeded the microbiological standards accepted by Brazilian legislation. These results indicate the need for a better product monitoring and more concern with hygiene and sanitary practices during industrial process.

  3. Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

  4. Administration of copper reduced the hyper-excitability of neurons in CA1 hippocampal slices from epileptic rats.

    Science.gov (United States)

    Leiva, Juan; Infante, Claudio

    2016-04-01

    Copper as a trace metal is involved in several neurodegenerative illnesses, such as Menkes, Wilson's, Alzheimer's, amyotrophic lateral sclerosis (ALS), and Creutzfeldt-Jakob. Electrophysiological evidence indicates that acute perfusion of copper can inhibit long-term synaptic potentiation in hippocampal slices. The objective of this work is to determine whether Cu perfusion can perturb synaptic transmission in hippocampal slices derived from pilocarpine treated epileptic rats. Field potential (FP) recordings of the CA1 neurons of rats with chronic epilepsy showed voltage and response duration decrease following copper sulfate perfusion. However, voltage and response duration were higher after removing copper by washing. The discharge frequency of the CA1 neurons of hippocampal slices from non-epileptic control rats was increased after acute perfusion of 10 μM of pilocarpine. This increase was blocked by administering copper sulphate 10 μM. Krebs-Ringer solution washing re-established the discharges, with a higher frequency than that provoked by pilocarpine perfusion. We discuss the blocking effect of copper and the synaptic hyper-excitability generated by its removal. PMID:27548095

  5. Power law scaling in synchronization of brain signals depends on cognitive load

    Directory of Open Access Journals (Sweden)

    Jose Luis ePerez Velazquez

    2014-05-01

    Full Text Available As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task. There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa, which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviours.

  6. Power law scaling in synchronization of brain signals depends on cognitive load.

    Science.gov (United States)

    Tinker, Jesse; Velazquez, Jose Luis Perez

    2014-01-01

    As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task). There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa), which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviors.

  7. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  8. Modelling of lactic fermentation of carrot slices in salted brines

    OpenAIRE

    Nabais, R.M.; Malcata, F. X.

    1997-01-01

    Increases in suspended biomass and variation in the concentrations of reducing sugars, salt, and lactic acid in brine containing sliced carrots were followed for a period of several days. A tentative unstructured, unsegregated model for the metabolism of suspended Lactobacillus plan tarum coupled with Fick's second law of diffusion for the transport of solutes within the carrot material was postulated. This general model was fitted by non-linear multiresponse regression analysis to an extensi...

  9. On the concordance genus of topologically slice knots

    OpenAIRE

    Hom, Jennifer

    2012-01-01

    The concordance genus of a knot K is the minimum Seifert genus of all knots smoothly concordant to K. Concordance genus is bounded below by the 4-ball genus and above by the Seifert genus. We give a lower bound for the concordance genus of K coming from the knot Floer complex of K. As an application, we prove that there are topologically slice knots with 4-ball genus equal to one and arbitrarily large concordance genus.

  10. Comparison between powder and slices diffraction methods in teeth samples

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, Marcos V.; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada; Porto, Isabel M. [Universidade Estadual de Campinas (FOP/UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia; Gerlach, Raquel F. [Universidade de Sao Paulo (FORP/USP), Rieirao Preto, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia, Estomatologia e Fisiologia; Costa, Fanny N. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10{sup -1}0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  11. CONDITIONED SLICING FOR EFFICIENT MULTIWAY DECISION GRAPHS MODEL-CHECKER

    Directory of Open Access Journals (Sweden)

    Saad Elmansori

    2013-01-01

    Full Text Available Integrating formal verification techniques into the hardware design process provides the means to rigorously prove critical properties. However, most automatic verification techniques, such as model checking, are only effectively applicable to designs of limited sizes due to the state explosion problem. The Multiway Decision Graphs (MDG method is an efficient method to define hardware designs into more abstract environments; however, the MDG model checker (MDG-MC still suffers from the state explosion problem. Furthermore, all the backward reduction algorithms cannot be used in MDG, due to the presence of abstract state variables. In this study, an efficient extractor for MDG Hardware Descrpiton Languge (MDG-HDL is introduced based on static (SS-MDG and conditioned (CS-MDG program slicing techniques. The techniques can obtain a chaining slice for given signals of interest. The main advantages of these techniques are: It has no MDG-HDL coding style limitation, it is accurate and it is competent in dealing with various MDG-HDL constructions. The main motivation for introducing this approach is to tackle the state explosion problem of MDG-MC that big MDG-HDL may cause. We apply our proposed techniques on different MDG-HDL designs and our analyses have shown that the proposed reduction techniques resulted in significantly improved performance of the MDG-MC. In this study, we present a general idea of program slicing, a discussion of how to slice MDG-HDL programs, implementation of the tool and a brief overview of some applications and experimental results. The underlying method and the tool based on it need to be empirically evaluated when applying to various applications.

  12. Organotypic Slice Cultures to Study Oligodendrocyte Dynamics and Myelination

    Science.gov (United States)

    Hill, Robert A.; Medved, Jelena; Patel, Kiran D.; Nishiyama, Akiko

    2014-01-01

    NG2 expressing cells (polydendrocytes, oligodendrocyte precursor cells) are the fourth major glial cell population in the central nervous system. During embryonic and postnatal development they actively proliferate and generate myelinating oligodendrocytes. These cells have commonly been studied in primary dissociated cultures, neuron cocultures, and in fixed tissue. Using newly available transgenic mouse lines slice culture systems can be used to investigate proliferation and differentiation of oligodendrocyte lineage cells in both gray and white matter regions of the forebrain and cerebellum. Slice cultures are prepared from early postnatal mice and are kept in culture for up to 1 month. These slices can be imaged multiple times over the culture period to investigate cellular behavior and interactions. This method allows visualization of NG2 cell division and the steps leading to oligodendrocyte differentiation while enabling detailed analysis of region-dependent NG2 cell and oligodendrocyte functional heterogeneity. This is a powerful technique that can be used to investigate the intrinsic and extrinsic signals influencing these cells over time in a cellular environment that closely resembles that found in vivo. PMID:25177825

  13. Direct Slicing Based on Material Performance and Process Parameters for Selective Laser Sintering

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Direct slicing from CAD models to generate sectional contours of thepart to be sintered for Selective Laser Sintering (SLS) may overcome inherent disadvantages of using a Stereo Lithography ( STL ) format. In this paper, a direct slicing procedure is proposed for Selective Laser Sintering based on material performance and process parameters. Slicing thickness depends on the 3 D geometric model,material performance and process parameters. The relationship among material performance, process parameters and the largest slicing thickness is established using analysis of a sintering temperature field. A dynamic linked library is developed to realize direct slicing from a CAD model.

  14. Brain plasticity and functionality explored by nonlinear optical microscopy

    Science.gov (United States)

    Sacconi, L.; Allegra, L.; Buffelli, M.; Cesare, P.; D'Angelo, E.; Gandolfi, D.; Grasselli, G.; Lotti, J.; Mapelli, J.; Strata, P.; Pavone, F. S.

    2010-02-01

    In combination with fluorescent protein (XFP) expression techniques, two-photon microscopy has become an indispensable tool to image cortical plasticity in living mice. In parallel to its application in imaging, multi-photon absorption has also been used as a tool for the dissection of single neurites with submicrometric precision without causing any visible collateral damage to the surrounding neuronal structures. In this work, multi-photon nanosurgery is applied to dissect single climbing fibers expressing GFP in the cerebellar cortex. The morphological consequences are then characterized with time lapse 3-dimensional two-photon imaging over a period of minutes to days after the procedure. Preliminary investigations show that the laser induced fiber dissection recalls a regenerative process in the fiber itself over a period of days. These results show the possibility of this innovative technique to investigate regenerative processes in adult brain. In parallel with imaging and manipulation technique, non-linear microscopy offers the opportunity to optically record electrical activity in intact neuronal networks. In this work, we combined the advantages of second-harmonic generation (SHG) with a random access (RA) excitation scheme to realize a new microscope (RASH) capable of optically recording fast membrane potential events occurring in a wide-field of view. The RASH microscope, in combination with bulk loading of tissue with FM4-64 dye, was used to simultaneously record electrical activity from clusters of Purkinje cells in acute cerebellar slices. Complex spikes, both synchronous and asynchronous, were optically recorded simultaneously across a given population of neurons. Spontaneous electrical activity was also monitored simultaneously in pairs of neurons, where action potentials were recorded without averaging across trials. These results show the strength of this technique in describing the temporal dynamics of neuronal assemblies, opening promising

  15. Recomendações técnicas para o registro do eletrencefalograma (EEG na suspeita da morte encefálica Guidelines for electroencephalogram (eeg recording in suspected brain death

    Directory of Open Access Journals (Sweden)

    FRANCISCO JOSÉ C. LUCCAS

    1998-09-01

    Full Text Available Neste trabalho, desenvolvido por uma comissão nomeada pela Sociedade Brasileira de Neurofisiologia Clínica, são apresentadas as recomendações referentes ao registro do eletrencefalograma (EEG nos casos de suspeita de morte encefálica, enfatizando que, apesar do necessário respeito aos parâmetros técnicos, o método não visa substituir o exame neurológico, mas complementá-lo.Brazilian Clinical Neurophysiology Society guidelines and pertaining comments concerning electroencephalogram (EEG recording in suspected brain death are presented. EEG is not intended as a substitute, rather as a complement to neurologic evaluation.

  16. Alteration in rectification of potassium channels in perinatal hypoxia ischemia brain damage.

    Science.gov (United States)

    Chen, Penghui; Wang, Liyan; Deng, Qiyue; Ruan, Huaizhen; Cai, Wenqin

    2015-01-15

    Oligodendrocyte progenitor cells (OPCs) are susceptible to perinatal hypoxia ischemia brain damage (HIBD), which results in infant cerebral palsy due to the effects on myelination. The origin of OPC vulnerability in HIBD, however, remains controversial. In this study, we defined the HIBD punctate lesions by MRI diffuse excessive high signal intensity (DEHSI) in postnatal 7-day-old rats. The electrophysiological functional properties of OPCs in HIBD were recorded by patch-clamp in acute cerebral cortex slices. The slices were intracellularly injected with Lucifer yellow and immunohistochemically labeled with NG2 antibody to identify local OPCs. Passive membrane properties and K(+) channel functions in OPCs were analyzed to estimate the onset of vulnerability in HIBD. The resting membrane potential, membrane resistance, and membrane capacitance of OPCs were increased in both the gray and white matter of the cerebral cortex. OPCs in both the gray and white matter exhibited voltage-dependent K(+) currents, which consisted of the initiated rectified potassium currents (IA) and the sustained rectified currents (IK). The significant alternation in membrane resistance was influenced by the diversity of potassium channel kinetics. These findings suggest that the rectification of IA and IK channels may play a significant role in OPC vulnerability in HIBD.

  17. The topology of large-scale structure. VI - Slices of the universe

    Science.gov (United States)

    Park, Changbom; Gott, J. R., III; Melott, Adrian L.; Karachentsev, I. D.

    1992-01-01

    Results of an investigation of the topology of large-scale structure in two observed slices of the universe are presented. Both slices pass through the Coma cluster and their depths are 100 and 230/h Mpc. The present topology study shows that the largest void in the CfA slice is divided into two smaller voids by a statistically significant line of galaxies. The topology of toy models like the white noise and bubble models is shown to be inconsistent with that of the observed slices. A large N-body simulation was made of the biased cloud dark matter model and the slices are simulated by matching them in selection functions and boundary conditions. The genus curves for these simulated slices are spongelike and have a small shift in the direction of a meatball topology like those of observed slices.

  18. Imaging and recording subventricular zone progenitor cells in live tissue of postnatal mice

    Directory of Open Access Journals (Sweden)

    Benjamin Lacar

    2010-07-01

    Full Text Available The subventricular zone (SVZ is one of two regions where neurogenesis persists in the postnatal brain. The SVZ, located along the lateral ventricle, is the largest neurogenic zone in the brain that contains multiple cell populations including astrocyte-like cells and neuroblasts. Neuroblasts migrate in chains to the olfactory bulb where they differentiate into interneurons. Here, we discuss the experimental approaches to record the electrophysiology of these cells and image their migration and calcium activity in acute slices. Although these techniques were in place for studying glial cells and neurons in mature networks, the SVZ raises new challenges due to the unique properties of SVZ cells, the cellular diversity, and the architecture of the region. We emphasize different methods, such as the use of transgenic mice and in vivo electroporation that permit identification of the different SVZ cell populations for patch clamp recording or imaging. Electroporation also permits genetic labeling of cells using fluorescent reporter mice and modification of the system using either RNA interference technology or floxed mice. In this review, we aim to provide conceptual and technical details of the approaches to perform electrophysiological and imaging studies of SVZ cells.

  19. Record Schedules

    Data.gov (United States)

    Department of Homeland Security — A records schedule describes FAA records, identifies the records as either temporary or permanent, and provides specific, mandatory instructions for the disposition...

  20. Live Imaging of the Ependymal Cilia in the Lateral Ventricles of the Mouse Brain.

    Science.gov (United States)

    Al Omran, Alzahra J; Saternos, Hannah C; Liu, Tongyu; Nauli, Surya M; AbouAlaiwi, Wissam A

    2015-01-01

    Multiciliated ependymal cells line the ventricles in the adult brain. Abnormal function or structure of ependymal cilia is associated with various neurological deficits. The current ex vivo live imaging of motile ependymal cilia technique allows for a detailed study of ciliary dynamics following several steps. These steps include: mice euthanasia with carbon dioxide according to protocols of The University of Toledo's Institutional Animal Care and Use Committee (IACUC); craniectomy followed by brain removal and sagittal brain dissection with a vibratome or sharp blade to obtain very thin sections through the brain lateral ventricles, where the ependymal cilia can be visualized. Incubation of the brain's slices in a customized glass-bottom plate containing Dulbecco's Modified Eagle's Medium (DMEM)/High-Glucose at 37 °C in the presence of 95%/5% O2/CO2 mixture is essential to keep the tissue alive during the experiment. A video of the cilia beating is then recorded using a high-resolution differential interference contrast microscope. The video is then analyzed frame by frame to calculate the ciliary beating frequency. This allows distinct classification of the ependymal cells into three categories or types based on their ciliary beating frequency and angle. Furthermore, this technique allows the use of high-speed fluorescence imaging analysis to characterize the unique intracellular calcium oscillation properties of ependymal cells as well as the effect of pharmacological agents on the calcium oscillations and the ciliary beating frequency. In addition, this technique is suitable for immunofluorescence imaging for ciliary structure and ciliary protein localization studies. This is particularly important in disease diagnosis and phenotype studies. The main limitation of the technique is attributed to the decrease in live motile cilia movement as the brain tissue starts to die. PMID:26067390

  1. Vortices in brain waves

    OpenAIRE

    Freeman, Walter J III; Vitiello, Giuseppe

    2008-01-01

    Interactions by mutual excitation in neural populations in human and animal brains cre- ate a mesoscopic order parameter that is recorded in brain waves (electroencephalogram, EEG). Spatially and spectrally distributed oscillations are imposed on the background activity by inhibitory feedback in the gamma range (30–80 Hz). Beats recur at theta rates (3–7 Hz), at which the order parameter transiently approaches zero and micro- scopic activity becomes disordered. After these null spikes, the or...

  2. Stretchable microelectrode arrays--a tool for discovering mechanisms of functional deficits underlying traumatic brain injury and interfacing neurons with neuroprosthetics.

    Science.gov (United States)

    Yu, Zhe; Tsay, Candice; Lacour, Stéphanie P; Wagner, Sigurd; Morrison, Barclay

    2006-01-01

    Traumatic brain injury (TBI) can be caused by motor vehicle accidents, falls and firearms. TBI can result in major neurological dysfunction such as chronic seizures and memory disturbances. To discover mechanisms of functional deficits underlying TBI, we developed a stretchable microelectrode array (SMEA),which can be used for continuous recording of neuronal function, pre-, during, and post-stretch injury. TheSMEA was fabricated on a polydimethylsiloxane (PDMS)substrate with stretchable, 100 pm wide, 25 nm thick gold electrodes patterned there on [1]. The electrodes were encapsulated with a 10-20 microm thick, photo-patternable PDMS insulation layer. Previous biocompatibility tests showed no overt necrosis or cell death caused by the SMEAs after 2 weeks in culture [2]. The electrical performance of the SMEAs was tested in electrophysiological saline solution before, during and after biaxial stretching. The results showed that the electrode impedance increased with the strain to reach 800 kL at 8.5% strain and then recovered to 10 kil after relaxation. The working noise level remained below 20 pV pp during the whole process. New methodologiesf or improving the patterning of the encapsulation layer were tested on gold electrode arrays supported on glass. With these prototype arrays, robust population spikes were recorded from organotypic hippocampal slice cultures of brain tissue. Additionally, seizure-like activity induced with 1 mM bicuculline was also recorded. Our results demonstrate that the prototype arrays have good electrical performance compatible with existing multielectrode array systems. They also indicate the ability to record neuronal activity from hippocampal slices. This novel technology will enable new studies to understand injury mechanisms leading to post-traumatic neuronal dysfunction. PMID:17959498

  3. The influence of heart rate, slice thickness, and calcification density on calcium scores using 64-slice multidetector computed tomography - A systematic phantom study

    NARCIS (Netherlands)

    Groen, Jaap M.; Greuter, Marcel J.; Schmidt, Bernhard; Suess, Christoph; Vliegenthart, Rozemarijn; Oudkerk, Matthis

    2007-01-01

    Objective: The purpose of this study was to investigate the influence of heart rate, slice thickness, and calcification density on absolute value and variability of calcium score using 64-slice multidetector computed tomography (MDCT). Methods and Materials: Three artificial arteries containing each

  4. Effect of anatomical noise on the detectability of cone beam CT images with different slice direction, slice thickness, and volume glandular fraction.

    Science.gov (United States)

    Han, Minah; Park, Subok; Baek, Jongduk

    2016-08-22

    We investigate the effect of anatomical noise on the detectability of cone beam CT (CBCT) images with different slice directions, slice thicknesses, and volume glandular fractions (VGFs). Anatomical noise is generated using a power law spectrum of breast anatomy, and spherical objects with diameters from 1mm to 11mm are used as breast masses. CBCT projection images are simulated and reconstructed using the FDK algorithm. A channelized Hotelling observer (CHO) with Laguerre-Gauss (LG) channels is used to evaluate detectability for the signal-known-exactly (SKE) binary detection task. Detectability is calculated for various slice thicknesses in the transverse and longitudinal planes for 15%, 30% and 60% VGFs. The optimal slice thicknesses that maximize the detectability of the objects are determined. The results show that the β value increases as the slice thickness increases, but that thicker slices yield higher detectability in the transverse and longitudinal planes, except for the case of a 1mm diameter spherical object. It is also shown that the longitudinal plane with a 0.1mm slice thickness provides higher detectability than the transverse plane, despite its higher β value. With optimal slice thicknesses, the longitudinal plane exhibits better detectability for all VGFs and spherical objects. PMID:27557168

  5. Neuroprotection of Persea major extract against oxygen and glucose deprivation in hippocampal slices involves increased glutamate uptake and modulation of A1 and A2A adenosine receptors

    Directory of Open Access Journals (Sweden)

    Marielli Letícia Fedalto

    2013-10-01

    Full Text Available Ischemic stroke is characterised by a lack of oxygen and glucose in the brain, leading to excessive glutamate release and neuronal cell death. Adenosine is produced in response to ATP depletion and acts as an endogenous neuromodulator that reduces excitotoxicity. Persea major (Meins. L.E. Kopp (Lauraceae is a medical plant that is indigenous to South Brazil, and the rural population has used it medicinally due to its anti-inflammatory properties. The aim of this study was to evaluate the neuroprotective effect of Persea major methanolic extract against oxygen and glucose deprivation and re-oxygenation as well as to determine its underlying mechanism of action in hippocampal brain slices. Persea major methanolic extract (0.5 mg/ml has a neuroprotective effect on hippocampal slices when added before or during 15 min of oxygen and glucose deprivation or 2 h of re-oxygenation. Hippocampal slices subjected to oxygen and glucose deprivation and re-oxygenation showed significantly reduced glutamate uptake, and the addition of Persea major methanolic extract in the re-oxygenation period counteracted the reduction of glutamate uptake. The presence of A1 or A2A, but not A2B or A3 receptor antagonists, abolished the neuroprotective effect of Persea major methanolic extract. In conclusion, the neuroprotective effect of Persea majormethanolic extract involves augmentation of glutamate uptake and modulation of A1 and A2B adenosine receptors.

  6. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    2012-12-01

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

  7. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    ravi kumar

    2012-12-01

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

  8. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  9. Brain Basics

    Medline Plus

    Full Text Available ... as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the brain ... specialized for the function of conducting messages. A neuron has three basic parts: Cell body which includes ...

  10. Brain surgery

    Science.gov (United States)

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  11. Brain Malformations

    Science.gov (United States)

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  12. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... others live with symptoms of mental illness every day. They can be moderate, or serious and cause ...

  13. Brain Basics

    Medline Plus

    Full Text Available ... The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the ... distant nerve cells (via axons) to form brain circuits. These circuits control specific body functions such as ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... Basics will introduce you to some of this science, such as: How the brain develops How genes and the environment affect the brain The basic structure of the brain How different parts of ...

  15. Brain Basics

    Medline Plus

    Full Text Available ... science, such as: How the brain develops How genes and the environment affect the brain The basic ... that with brain development in people mental disorders. Genes and environmental cues both help to direct this ...

  16. Inhibition of intermediary metabolism by amiodarone in dog thyroid slices

    Energy Technology Data Exchange (ETDEWEB)

    Pasquali, D.; Tseng, F.Y.; Rani, C.S.; Field, J.B. (Baylor College of Medicine, Houston, TX (USA))

    1990-10-01

    Amiodarone, an iodine-containing antiarrhythmic drug, has been reported to interfere with thyroid function and thyroid hormone metabolism. We studied the effects of amiodarone on basal and agonist (thyroid-stimulating hormone (TSH), phorbol ester, or carbachol)-stimulated glucose oxidation, 32PO4 incorporation into phospholipids, and adenosine 3',5'-cyclic monophosphate (cAMP) concentration in dog thyroid slices. Slices were preincubated with amiodarone at 37 degrees C for 1 h before the addition of agonist and the appropriate radioisotope. cAMP stimulation was measured after 20 min, glucose oxidation for 45 min, and 32PO4 incorporation into phospholipids for 2 h. Amiodarone (0.5 mM) had no effect on basal 14CO2 formation or 32PO4 incorporation into phospholipids but significantly inhibited TSH, phorbol ester, and carbachol stimulation of these parameters. It also inhibited cAMP stimulation by TSH. Inhibition of TSH-stimulated (14C)glucose oxidation was also obtained with another iodide-containing compound, iopanoic acid (0.5 mM), but not with iothalamate (up to 10 mM). Inhibition by amiodarone was still present, but to a lesser extent, when it was added at the same time as the agonist. Inhibition of stimulated (14C)glucose oxidation persisted even after the slices were incubated without amiodarone for 6 h. Inhibition by amiodarone, in contrast to that by inorganic iodide, was not prevented by 1 mM methimazole added at the same time as amiodarone. These results indicate that the inhibitory effects of amiodarone on thyroid function are not due to dissociation of iodide from the molecule.

  17. SYNCHROTRON RADIATION XRF MICROPROBE STUDY OF HUMAN BONE TUMOR SLICE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The experimental apparatus of X-ray fluorescence (XRF) microprobe analysis at Beijing Synchrotron Radiation Facility (BSRF) is described Using the bovine liver as the standard reference.the minimum detection limit(MDL) of trace element was measured to determine the capability of biological sample analysis by synchrotron radiation XRF microprobe.The relative change of the content of the major or trace element in the normal and tumor part of human bone tissue slice was investigated The experimental result relation to the clinical medicine was also discussed.

  18. Rational-slice Knots via Strongly Negative-amphicheiral Knots

    Institute of Scientific and Technical Information of China (English)

    KAWAUCHI AKIO

    2009-01-01

    We show that certain satellite knots of every strongly negative-amphicheiral rational knot are rational-slice knots. This proof also shows that the 0-surgery man-ifold of a certain strongly negative amphicheiral knot such as the figure-eight knot bounds a compact oriented smooth 4-manifold homotopy equivalent to the 2-sphere such that a second homology class of the 4-manifold is represented by a smoothly embedded 2-sphere if and only if the modulo two reduction of it is zero.

  19. Maximal slicings in spherical symmetry: local existence and construction

    CERN Document Server

    Cordero-Carrión, Isabel; Morales-Lladosa, Juan Antonio; 10.1063/1.3658864

    2011-01-01

    We show that any spherically symmetric spacetime locally admits a maximal spacelike slicing and we give a procedure allowing its construction. The construction procedure that we have designed is based on purely geometrical arguments and, in practice, leads to solve a decoupled system of first order quasi-linear partial differential equations. We have explicitly built up maximal foliations in Minkowski and Friedmann spacetimes. Our approach admits further generalizations and efficient computational implementation. As by product, we suggest some applications of our work in the task of calibrating Numerical Relativity complex codes, usually written in Cartesian coordinates.

  20. Coronary artery imaging with 64-slice spiral CT in atrial fibrillation patients: initial experience

    International Nuclear Information System (INIS)

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice spiral CT in patient with atrial fibrillation. Methods: The images of 31 patients with atrial fibrillation who underwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software. Ten patients additionally underwent conventional coronary angiography. The results of conventional coronary angiography were compared with CT coronary angiography of the 10 patients. Results: Image reconstruction was based on absolute timing. The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 85, 41, 5, and 8 vessel segments respectively in patient group with heart rate between 47 beat per minent (bpm) and 69 bpm; and in 63, 16, 13, and 15 vessel segments respectively in patent group with heart rate between 70 bpm and 79 bpm;and in 46, 25, 23, and 24 vessel segments in patient group with heart rate between 80 bpm and 105 bpm. There was significant difference among the three patient groups (H=22.08, P<0.01). Comparison was carried out between CT angiographic findings and conventional angiographic findings of the 125 segments of the coronary arteries in the 10 patients who underwent conventional coronary angiography. The sensitivity and specificity of CT angiography for diagnosing vessel with significant coronary stenosis (≥50% narrowing) was 85.0% (17/20) and 95.2% (100/105), respectively. Positive predictive value was 77.3% (17/22), and negative predictive value was 97.1% (100/103). Coronary CTA underestimated the lesions of 3 vessel segments and overestimated the lesions of 5 vessel segments. Conclusion: Coronary artery imaging with 64-slice row CT had clinical value for patients with atrial fibrillation

  1. The feasibility study of 80 kV in 128-slice MSCT pulmonary angiography

    International Nuclear Information System (INIS)

    Objective: To investigate the influence of 80 kV on dose reduction and image quality in 128-slice CT pulmonary angiography (CTPA) compared with the conventional 120 kV. Methods: Sixty patients suspected of pulmonary embolism (PE) who underwent CTPA were randomly divided into 80 kV and 120 kV groups by random digits table method. All the patients underwent CTPA with automatic tube current modulation. The values of volume CT dose index (CTDIvol),dose length product (DLP) were recorded and effective dose (E) was calculated. The attenuation was measured in central and peripheral pulmonary arteries as well as background noise (BN), then signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. The radiation exposure, pulmonary arterial enhancement, background noise, SNR, CNR and scores of image quality by a 5-point scale were compared between two groups. Results: E value was significantly lower at 80 kV [(0.99 ± 0.27) mSv] compared with 120 kV [(3.02 ± 0.87) mSv, t =12.281, P<0.05]. The mean attenuation value of pulmonary arteries as well as BN in 80 kV group were significantly higher than in 120 kV group (P<0.05). SNR and CNR did not differ significantly between two groups. No significant difference was detected on scores of image quality (P>0.05). Conclusions: The application of 80 kV protocol combined with automatic tube current modulation scanning in 128-slice MSCT pulmonary angiography could significantly reduce radiation dose compared with the conventional 120 kV protocol without deterioration in diagnostic image quality. (authors)

  2. A Prototype Two-Axis Laser Scanning System used in Stereolithography Apparatus with New Algorithms for Computerized Model Slicing

    OpenAIRE

    Habibi, M.; H. Shahmohammadi; V. Taraghi; S. D. Safari; B. Arezoo

    2009-01-01

    Problem statement: A successful operation of rapid prototyping process depends on software and hardware which are used in RP machines. About software, an efficient technique is required to slice the CAD model. Several slicing methods are used for slicing from Standard Triangulation Language (STL) files, such as direct slicing and adaptive slicing. Using these methods reduce accuracy of physical part or increase process time. About hardware, in Stereolithography (SLA) apparatus, two mirrors ha...

  3. Performance of a Self-Paced Brain Computer Interface on Data Contaminated with Eye-Movement Artifacts and on Data Recorded in a Subsequent Session

    Directory of Open Access Journals (Sweden)

    Mehrdad Fatourechi

    2008-01-01

    Full Text Available The performance of a specific self-paced BCI (SBCI is investigated using two different datasets to determine its suitability for using online: (1 data contaminated with large-amplitude eye movements, and (2 data recorded in a session subsequent to the original sessions used to design the system. No part of the data was rejected in the subsequent session. Therefore, this dataset can be regarded as a “pseudo-online” test set. The SBCI under investigation uses features extracted from three specific neurological phenomena. Each of these neurological phenomena belongs to a different frequency band. Since many prominent artifacts are either of mostly low-frequency (e.g., eye movements or mostly high-frequency nature (e.g., muscle movements, it is expected that the system shows a fairly robust performance over artifact-contaminated data. Analysis of the data of four participants using epochs contaminated with large-amplitude eye-movement artifacts shows that the system's performance deteriorates only slightly. Furthermore, the system's performance during the session subsequent to the original sessions remained largely the same as in the original sessions for three out of the four participants. This moderate drop in performance can be considered tolerable, since allowing artifact-contaminated data to be used as inputs makes the system available for users at ALL times.

  4. Development of the Young Brain

    Medline Plus

    Full Text Available ... very early in life we have our five senses where our visual system and audio system is ... Early evidence suggests -pretty well. In fact, the human brain has a track record of successfully adapting ...

  5. Development of the Young Brain

    Medline Plus

    Full Text Available ... Early evidence suggests -pretty well. In fact, the human brain has a track record of successfully adapting ... reading. Dr. Giedd: It’s sobering to realize most humans that have lived and died have never read. ...

  6. Rapid ultrathin slice plastination of embalmed specimens with minimal tissue loss.

    Science.gov (United States)

    Soal, S; Pollard, M; Burland, G; Lissaman, R; Wafer, M; Stringer, M D

    2010-07-01

    A modified technique of producing 1 mm (ultrathin) E12 plastinated slices of tissue specimens from embalmed cadavers for anatomical teaching and research is described. Specimens up to 150 mm in length and width were embedded in polyurethane foam and serially sectioned using an OMAS C300 food slicer. Individual slices were then processed by cold dehydration, degreasing, resin impregnation, mounting and curing. Bone-containing specimens were first decalcified. Tissue slices could be cut with remarkable accuracy (0.98 +/- 0.01 mm per slice) and minimal tissue loss (less than 2% per slice). The entire production process could be achieved in 25 days and was associated with tissue volume shrinkage of no more than 6%. These results demonstrate a relatively rapid method of producing ultrathin E12 slices with minimal tissue loss. The technique may be particularly applicable to submacroscopic morphologic studies and three-dimensional reconstruction in clinical anatomy. PMID:20235170

  7. Can outer-to-outer diameter be used alone in diagnosing appendicitis on 128-slice MDCT?

    Institute of Scientific and Technical Information of China (English)

    Jamal; Yaqoob; Muhammad; Idris; Muhammad; Shahbaz; Alam; Nazia; Kashif

    2014-01-01

    AIM: To assess the frequency of visualization, position and diameter of normal appendix on 128-slice multidetector computed tomography(MDCT) in adult population.METHODS: Retrospective cross sectional study conducted at Radiology Department, Dallah Hospital, Riyadh, Saudi Arabia from March 2013 to October 2013. Non-enhanced computed tomography scans of abdomen and pelvis of 98 patients presenting with hematuria(not associated with abdominal pain, fever or colonic disease) were reviewed by two radiologists, blinded to patient history. The study group included 55 females and 43 males with overall mean age of 54.7 years(range 21 to 94 years). The coronal reformatted images were reviewed in addition to the axial images. The frequency of visualization of appendix was recorded with assessment of position, diameter and luminal contents.RESULTS: The appendix was recorded as definitely visualized in 99% of patients and mean outer-to-outer diameter of the appendix was 5.6 ± 1.3 mm(range 3.0-11.0 mm).CONCLUSION: MDCT with its multiplanar reformation display is extremely useful for visualization of normal appendix. The normal appendix is very variable in its position and diameter. In the absence of other signs, the diagnosis of acute appendix should not be made solely on outer-to-outer appendiceal diameter.

  8. Cultivar affects browning susceptibility of freshly cut star fruit slices

    Directory of Open Access Journals (Sweden)

    Teixeira Gustavo Henrique de Almeida

    2006-01-01

    Full Text Available Consumption of freshly-cut horticultural products has increased in the last few years. The principal restraint to using freshly-cut carambola is its susceptibility to tissue-browning, due to polyphenol oxidase-mediated oxidation of phenolic compounds present in the tissue. The current study investigated the susceptibility to browning of star fruit slices (Averrhoa carambola L. of seven genotypes (Hart, Golden Star, Taen-ma, Nota-10, Malásia, Arkin, and Fwang Tung. Cultivar susceptibility to browning as measured by luminosity (L* varied significantly among genotypes. Without catechol 0.05 M, little changes occurred on cut surface of any cultivars during 6 hour at 25degreesC, 67% RH. Addition of catechol led to rapid browning, which was more intense in cvs. Taen-ma, Fwang Tung, and Golden Star, with reduction in L* value of 28.60%, 27.68%, and 23.29%, respectively. Browning was more intense in the center of the slices, particularly when treated with catechol, indicating highest polyphenol oxidase (PPO concentration. Epidermal browning, even in absence of catechol, is a limitation to visual acceptability and indicates a necessity for its control during carambola processing. Care must be given to appropriate selection of cultivars for fresh-cut processing, since cultivar varied in browning susceptibility in the presence of catechol.

  9. Assessment of aec system response in ge 16 slices scanner

    International Nuclear Information System (INIS)

    Computed Tomography scanners equipped with system for Automatic Exposure Control ( AEC ) have been recently installed into clinical practice in Macedonia. Assessment of their AEC settings and performances is important task from patient doses and images quality point of view . This study was done by analyzing of CT examinations in patients in the City Hospital ' 8 September' in Skopje. The examinations were carried out by GE Bright Speed 16 slices scanner equipped with AEC system . In all patients were applied the same protocol with constant acquisition parameters was applied , and images were reconstructed by standard mode . Patient dimensions and image noise were measured from the scouts and axial images. From DICOM header the information related to dose, TCM and slice position were extracted . It was found that scanner automatic exposure system adjusts exposure mainly according to maximal patient lateral dimension (LR) and applying the same Noise Index (NI) value in patients with different size does not provides necessarily the same image noise level. In patients which LR dimension was less than 30 cm it was found that AEC adjusts tube current at the minimum of m A interval with no modulation throughout different body parts. (Author)

  10. Slices: A shape-proxy based on planar sections

    KAUST Repository

    McCrae, James

    2011-12-01

    Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours of intersection of planes with a 3D object, for creating shape abstractions, motivated by their popularity in art and engineering. We first perform a user study to show that humans do define consistent and similar planar section proxies for common objects. Interestingly, we observe a strong correlation between user-defined planes and geometric features of objects. Further we show that the problem of finding the minimum set of planes that capture a set of 3D geometric shape features is both NP-hard and not always the proxy a user would pick. Guided by the principles inferred from our user study, we present an algorithm that progressively selects planes to maximize feature coverage, which in turn influence the selection of subsequent planes. The algorithmic framework easily incorporates various shape features, while their relative importance values are computed and validated from the user study data. We use our algorithm to compute planar slices for various objects, validate their utility towards object abstraction using a second user study, and conclude showing the potential applications of the extracted planar slice shape proxies.

  11. Large-scale, high-resolution multielectrode-array recording depicts functional network differences of cortical and hippocampal cultures.

    Directory of Open Access Journals (Sweden)

    Shinya Ito

    Full Text Available Understanding the detailed circuitry of functioning neuronal networks is one of the major goals of neuroscience. Recent improvements in neuronal recording techniques have made it possible to record the spiking activity from hundreds of neurons simultaneously with sub-millisecond temporal resolution. Here we used a 512-channel multielectrode array system to record the activity from hundreds of neurons in organotypic cultures of cortico-hippocampal brain slices from mice. To probe the network structure, we employed a wavelet transform of the cross-correlogram to categorize the functional connectivity in different frequency ranges. With this method we directly compare, for the first time, in any preparation, the neuronal network structures of cortex and hippocampus, on the scale of hundreds of neurons, with sub-millisecond time resolution. Among the three frequency ranges that we investigated, the lower two frequency ranges (gamma (30-80 Hz and beta (12-30 Hz range showed similar network structure between cortex and hippocampus, but there were many significant differences between these structures in the high frequency range (100-1000 Hz. The high frequency networks in cortex showed short tailed degree-distributions, shorter decay length of connectivity density, smaller clustering coefficients, and positive assortativity. Our results suggest that our method can characterize frequency dependent differences of network architecture from different brain regions. Crucially, because these differences between brain regions require millisecond temporal scales to be observed and characterized, these results underscore the importance of high temporal resolution recordings for the understanding of functional networks in neuronal systems.

  12. Coculture System with an Organotypic Brain Slice and 3D Spheroid of Carcinoma Cells

    OpenAIRE

    Chuang, Han-Ning; Lohaus, Raphaela; Hanisch, Uwe-Karsten; Binder, Claudia; Dehghani, Faramarz; Pukrop, Tobias

    2013-01-01

    Patients with cerebral metastasis of carcinomas have a poor prognosis. However, the process at the metastatic site has barely been investigated, in particular the role of the resident (stromal) cells. Studies in primary carcinomas demonstrate the influence of the microenvironment on metastasis, even on prognosis1,2. Especially the tumor associated macrophages (TAM) support migration, invasion and proliferation3. Interestingly, the major target sites of metastasis possess tissue-specific macro...

  13. Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

    DEFF Research Database (Denmark)

    Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa;

    2008-01-01

    Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic di...

  14. Imaging of molecular surface dynamics in brain slices using single-particle tracking

    NARCIS (Netherlands)

    Biermann, N.B.; Sokoll, S.; Klueva, J.; Missler, M.; Wiegert, J.S.; Sibarita, J.B.; Heine, M.

    2014-01-01

    Organization of signalling molecules in biological membranes is crucial for cellular communication. Many receptors, ion channels and cell adhesion molecules are associated with proteins important for their trafficking, surface localization or function. These complexes are embedded in a lipid environ

  15. Imaging of molecular surface dynamics in brain slices using single-particle tracking

    OpenAIRE

    Biermann, N.B.; Sokoll, S.; Klueva, J.; Missler, M.; Wiegert, J. S.; Sibarita, J.B.; Heine, M.

    2014-01-01

    Organization of signalling molecules in biological membranes is crucial for cellular communication. Many receptors, ion channels and cell adhesion molecules are associated with proteins important for their trafficking, surface localization or function. These complexes are embedded in a lipid environment of varying composition. Binding affinities and stoichiometry of such complexes were so far experimentally accessible only in isolated systems or monolayers of cell culture. Visualization of mo...

  16. Erythropoietin improves synaptic transmission during and following ischemia in rat hippocampal slice cultures.

    Science.gov (United States)

    Weber, Astrid; Maier, Rolf F; Hoffmann, Ulrike; Grips, Martin; Hoppenz, Marc; Aktas, Ayse G; Heinemann, Uwe; Obladen, Michael; Schuchmann, Sebastian

    2002-12-27

    Erythropoietin (EPO) prevents neuronal damage following ischemic, metabolic, and excitotoxic stress. In this study evoked extracellular field potentials (FP) were used to investigate the effect of EPO on synaptic transmission in hippocampal slice cultures. EPO treated cultured slices (40 units/ml for 48 h) showed significantly increased FP during and following oxygen and glucose deprivation compared with untreated control slices. The addition of the Jak2 inhibitor AG490 (50 microM for 48 h) blocked the EPO effect. These data suggest that EPO improves synaptic transmission during and following ischemia in hippocampal slice cultures.

  17. Analisis Pengaruh Slice Thickness Terhadap Citra CT Scan Dengan Kasus Sinus Paranasal Pengguna Gigi Palsu Implan

    OpenAIRE

    Sinaga, Srituti

    2015-01-01

    Artifacts is a disturbance in the image display CT Scan . Has conducted a study on the analysis of effect image slice thickness CT Scan with cases of paranasal sinus users dentures implan. Slice thickness used is 1, 3, 5 and 7 mm. The riset in Radiology Pirngadi Hospital Medan. The results of research that the slice thickness of 1mm is 3,18D obtained a description of the larger artifacts, slice thickness 7 mm is 2,54D obtained a description of the artifacts on the wane ( a little ) and the si...

  18. Asymptotics for Kernel Estimation of Slicing Average Third-Moment Estimation

    Institute of Scientific and Technical Information of China (English)

    Li-ping Zhu; Li-xing Zhu

    2006-01-01

    To estimate central dimension-reduction space in multivariate nonparametric regression, Sliced Inverse Regression[7] (SIR), Sliced Average Variance Estimation[4] (SAVE) and Slicing Average Third-moment Estimation[14] (SAT) have been developed. Since slicing estimation has very different asymptotic behavior for SIR and SAVE, the relevant study has been made case by case, when the kernel estimators of SIR and SAVE share similar asymptotic properties. In this paper, we also investigate kernel estimation of SAT. We prove the asymptotic normality, and show that, compared with the existing results, the kernel smoothing for SIR, SAVE and SAT has very similar asymptotic behavior.

  19. The clinical efficacy of 1 mm-slice CT of the middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Kazuhiro; Noiri, Teruhisa [Kawanishi Municipal Hospital, Hyogo (Japan); Doi, Katsumi; Koizuka, Izumi; Tanaka, Hisashi; Mishiro, Yasuo; Okumura, Shin-ichi; Kubo, Takeshi

    2000-02-01

    The efficacy of the preoperative 1 mm-slice CT for evaluating the condition of the ossicular chain and the facial canal was assessed. CT findings were compared with the operative findings of middle ears in 120 cases of chronic otitis media or cholesteatoma that underwent tympanoplasty. The reliability of 1 mm-slice CT in detecting any defect of the ossicular chain was much superior to those of 2 mm-slice CT previously reported, and the difference between them is essential for preoperative information. On the other hand, thinner slice than 1 mm may be unnecessary, especially in routine use. (author)

  20. Oxygen glucose deprivation in rat hippocampal slice cultures results in alterations in carnitine homeostasis and mitochondrial dysfunction.

    Directory of Open Access Journals (Sweden)

    Thomas F Rau

    Full Text Available Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neuroprotective. Thus, this study was undertaken to elucidate the molecular mechanisms by which HI alters carnitine metabolism and to begin to elucidate the mechanism underlying the neuroprotective effect of L-carnitine (LCAR supplementation. Utilizing neonatal rat hippocampal slice cultures we found that oxygen glucose deprivation (OGD decreased the levels of free carnitines (FC and increased the acylcarnitine (AC: FC ratio. These changes in carnitine homeostasis correlated with decreases in the protein levels of carnitine palmitoyl transferase (CPT 1 and 2. LCAR supplementation prevented the decrease in CPT1 and CPT2, enhanced both FC and the AC∶FC ratio and increased slice culture metabolic viability, the mitochondrial membrane potential prior to OGD and prevented the subsequent loss of neurons during later stages of reperfusion through a reduction in apoptotic cell death. Finally, we found that LCAR supplementation preserved the structural integrity and synaptic transmission within the hippocampus after OGD. Thus, we conclude that LCAR supplementation preserves the key enzymes responsible for maintaining carnitine homeostasis and preserves both cell viability and synaptic transmission after OGD.

  1. Brain Basics

    Medline Plus

    Full Text Available ... Welcome. Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... highly developed area at the front of the brain that, in humans, plays a role in executive functions such as ...

  2. Brain Basics

    Medline Plus

    Full Text Available ... Research Modern research tools and techniques are giving scientists a more detailed understanding of the brain than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies ...

  3. Records Management

    Data.gov (United States)

    U.S. Environmental Protection Agency — All Federal Agencies are required to prescribe an appropriate records maintenance program so that complete records are filed or otherwise preserved, records can be...

  4. Rhythm generation by the pre-Bötzinger Complex in medullary slice and island preparations: Effects of adenosine A1 receptor activation

    Directory of Open Access Journals (Sweden)

    Shields Edward J

    2008-10-01

    Full Text Available Abstract Background The pre-Bötzinger complex (preBötC is a central pattern generator within the ventrolateral medulla oblongata's ventral respiratory group that is important for the generation of respiratory rhythm. Activation of adenosine A1 receptors (A1R depresses preBötC rhythmogenesis. Although it remains unclear whether A1R activation is important for organisms in a normal metabolic state, A1R activation is important to the response of the preBötC to metabolic stress, such as hypoxia. This study examined mechanisms linking A1R activation to depression of preBötC rhythmogenesis in medullary slice and island preparations from neonatal mice. Results Converting medullary slices to islands by cutting away much of the medullary tissue adjacent to the preBötC decreased the amplitude of action potential bursts generated by a population of neurons within the preBötC (recorded with an extracellular electrode, and integrated using a hardware integrator, without noticeably affecting burst frequency. The A1R agonist N6-Cyclopentyladenosine (NCPA reduced population burst frequency in slices by ca. 33% and in islands by ca. 30%. As in normal (drug-free artificial cerebrospinal fluid (aCSF, NCPA decreased burst frequency in slices when GABAAergic or GABAAergic and glycinergic transmission were blocked, and in islands when GABAAergic transmission was antagonized. Converting slices to island preparations decreased synaptic input to inspiratory neurons. NCPA further decreased the frequency of synaptic inputs to neurons in island preparations and lowered the input resistance of inspiratory neurons, even when chemical communication between neurons and other cells was impeded. Conclusion Together these data support the suggestion that depression of preBötC activity by A1R activation involves both decreased neuronal excitability and diminished inter-neuronal communication.

  5. Single nanoparticle tracking of [Formula: see text]-methyl-d-aspartate receptors in cultured and intact brain tissue.

    Science.gov (United States)

    Varela, Juan A; Ferreira, Joana S; Dupuis, Julien P; Durand, Pauline; Bouchet, Delphine; Groc, Laurent

    2016-10-01

    Recent developments in single-molecule imaging have revealed many biological mechanisms, providing high spatial and temporal resolution maps of molecular events. In neurobiology, these techniques unveiled that plasma membrane neurotransmitter receptors and transporters laterally diffuse at the surface of cultured brain cells. The photostability of bright nanoprobes, such as quantum dots (QDs), has given access to neurotransmitter receptor tracking over long periods of time with a high spatial resolution. However, our knowledge has been restricted to cultured systems, i.e., neurons and organotypic slices, therefore lacking several aspects of the intact brain rheology and connectivity. Here, we used QDs to track single glutamatergic [Formula: see text]-methyl-d-aspartate receptors (NMDAR) in acute brain slices. By delivering functionalized nanoparticles in vivo through intraventricular injections to rats expressing genetically engineered-tagged NMDAR, we successfully tracked the receptors in native brain tissue. Comparing NMDAR tracking to different classical brain preparations (acute brain slices, cultured organotypic brain slices, and cultured neurons) revealed that the surface diffusion properties shared several features and are also influenced by the nature of the extracellular environment. Together, we describe the experimental procedures to track plasma membrane NMDAR in dissociated and native brain tissue, paving the way for investigations aiming at characterizing receptor diffusion biophysics in intact tissue and exploring the physiopathological roles of receptor surface dynamics. PMID:27429996

  6. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Science.gov (United States)

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode. PMID:26271472

  7. Spectral decomposition of black-hole perturbations on hyperboloidal slices

    CERN Document Server

    Ansorg, Marcus

    2016-01-01

    In this paper we present a spectral decomposition of solutions to relativistic wave equations described on horizon penetrating hyperboloidal slices within a given Schwarzschild-black-hole background. The wave equa- tion in question is Laplace-transformed which leads to a spatial differential equation with a complex parameter. For initial data which are analytic with respect to a compactified spatial coordinate, this equation is treated with the help of the Mathematica-package in terms of a sophisticated Taylor series analysis. Thereby, all ingredients of the desired spectral decomposition arise explicitly to arbitrarily prescribed accuracy, including quasi normal modes, quasi normal mode amplitudes as well as the jump of the Laplace-transform along the branch cut. Finally, all contributions are put together to obtain via the inverse Laplace transformation the spectral de- composition in question. The paper explains extensively this procedure and includes detailed discussions of relevant aspects, such as the d...

  8. Semiquantitative correction of posttraumatic enophthalmos with sliced cartilage grafts.

    Science.gov (United States)

    Matsuo, K; Hirose, T; Furuta, S; Hayashi, M; Watanabe, T

    1989-03-01

    A simple surgical technique for correcting posttraumatic enophthalmos is described. The steps are as follows: (1) a plaster mold is obtained of the patient's face, (2) wax is added to the enophthalmic eye of the plaster mold until it becomes symmetrical, (3) the quantity of wax is measured, and (4) the same amount of sliced costal cartilage is implanted beneath the periosteum of the extended orbital wall behind the vertical axis of the globe. Using this technique, we have successfully treated six patients with traumatic orbital floor defects without complication. This approach is useful for decreasing the orbital volume using a semiquantitative procedure to estimate the amount of graft material required. In this respect, costal cartilage demonstrates a marked advantage, with stability and cosmetic appearance verified over 12 months of follow-up.

  9. Semiquantitative correction of posttraumatic enophthalmos with sliced cartilage grafts.

    Science.gov (United States)

    Matsuo, K; Hirose, T; Furuta, S; Hayashi, M; Watanabe, T

    1989-03-01

    A simple surgical technique for correcting posttraumatic enophthalmos is described. The steps are as follows: (1) a plaster mold is obtained of the patient's face, (2) wax is added to the enophthalmic eye of the plaster mold until it becomes symmetrical, (3) the quantity of wax is measured, and (4) the same amount of sliced costal cartilage is implanted beneath the periosteum of the extended orbital wall behind the vertical axis of the globe. Using this technique, we have successfully treated six patients with traumatic orbital floor defects without complication. This approach is useful for decreasing the orbital volume using a semiquantitative procedure to estimate the amount of graft material required. In this respect, costal cartilage demonstrates a marked advantage, with stability and cosmetic appearance verified over 12 months of follow-up. PMID:2919197

  10. Co-expression of VAL- and TMT-opsins uncovers ancient photosensory interneurons and motorneurons in the vertebrate brain.

    Directory of Open Access Journals (Sweden)

    Ruth M Fischer

    Full Text Available The functional principle of the vertebrate brain is often paralleled to a computer: information collected by dedicated devices is processed and integrated by interneuron circuits and leads to output. However, inter- and motorneurons present in today's vertebrate brains are thought to derive from neurons that combined sensory, integration, and motor function. Consistently, sensory inter-motorneurons have been found in the simple nerve nets of cnidarians, animals at the base of the evolutionary lineage. We show that light-sensory motorneurons and light-sensory interneurons are also present in the brains of vertebrates, challenging the paradigm that information processing and output circuitry in the central brain is shielded from direct environmental influences. We investigated two groups of nonvisual photopigments, VAL- and TMT-Opsins, in zebrafish and medaka fish; two teleost species from distinct habitats separated by over 300 million years of evolution. TMT-Opsin subclasses are specifically expressed not only in hypothalamic and thalamic deep brain photoreceptors, but also in interneurons and motorneurons with no known photoreceptive function, such as the typeXIV interneurons of the fish optic tectum. We further show that TMT-Opsins and Encephalopsin render neuronal cells light-sensitive. TMT-Opsins preferentially respond to blue light relative to rhodopsin, with subclass-specific response kinetics. We discovered that tmt-opsins co-express with val-opsins, known green light receptors, in distinct inter- and motorneurons. Finally, we show by electrophysiological recordings on isolated adult tectal slices that interneurons in the position of typeXIV neurons respond to light. Our work supports "sensory-inter-motorneurons" as ancient units for brain evolution. It also reveals that vertebrate inter- and motorneurons are endowed with an evolutionarily ancient, complex light-sensory ability that could be used to detect changes in ambient light spectra

  11. Persistent Gliosis Interferes with Neurogenesis in Organotypic Hippocampal Slice Cultures.

    Science.gov (United States)

    Gerlach, Johannes; Donkels, Catharina; Münzner, Gert; Haas, Carola A

    2016-01-01

    Neurogenesis in the adult hippocampus has become an intensively investigated research topic, as it is essential for proper hippocampal function and considered to bear therapeutic potential for the replacement of pathologically lost neurons. On the other hand, neurogenesis itself is frequently affected by CNS insults. To identify processes leading to the disturbance of neurogenesis, we made use of organotypic hippocampal slice cultures (OHSC), which, for unknown reasons, lose their neurogenic potential during cultivation. In the present study, we show by BrdU/Prox1 double-immunostaining that the generation of new granule cells drops by 90% during the first week of cultivation. Monitoring neurogenesis dynamically in OHSC from POMC-eGFP mice, in which immature granule cells are endogenously labeled, revealed a gradual decay of the eGFP signal, reaching 10% of initial values within 7 days of cultivation. Accordingly, reverse transcription quantitative polymerase chain reaction analysis showed the downregulation of the neurogenesis-related genes doublecortin and Hes5, a crucial target of the stem cell-maintaining Notch signaling pathway. In parallel, we demonstrate a strong and long-lasting activation of astrocytes and microglial cells, both, morphologically and on the level of gene expression. Enhancement of astroglial activation by treating OHSC with ciliary neurotrophic factor accelerated the loss of neurogenesis, whereas treatment with indomethacin or an antagonist of the purinergic P2Y12 receptor exhibited potent protective effects on the neurogenic outcome. Therefore, we conclude that OHSC rapidly lose their neurogenic capacity due to persistent inflammatory processes taking place after the slice preparation. As inflammation is also considered to affect neurogenesis in many CNS pathologies, OHSC appear as a useful tool to study this interplay and its molecular basis. Furthermore, we propose that modification of glial activation might bear the therapeutic potential

  12. Persistent gliosis interferes with neurogenesis in organotypic hippocampal slice cultures

    Directory of Open Access Journals (Sweden)

    Johannes eGerlach

    2016-05-01

    Full Text Available Neurogenesis in the adult hippocampus has become an intensively investigated research topic, as it is essential for proper hippocampal function and considered to bear therapeutic potential for the replacement of pathologically lost neurons. On the other hand, neurogenesis itself is frequently affected by CNS insults. To identify processes leading to the disturbance of neurogenesis, we made use of organotypic hippocampal slice cultures (OHSC, which, for unknown reasons, lose their neurogenic potential during cultivation. In the present study, we show by BrdU/Prox1 double-immunostaining that the generation of new granule cells drops by 90% during the first week of cultivation. Monitoring neurogenesis dynamically in OHSC from POMC-eGFP mice, in which immature granule cells are endogenously labeled, revealed a gradual decay of the eGFP signal, reaching 10% of initial values within seven days of cultivation. Accordingly, RT-qPCR analysis showed the downregulation of the neurogenesis-related genes doublecortin and Hes5, a crucial target of the stem cell-maintaining Notch signaling pathway. In parallel, we demonstrate a strong and long-lasting activation of astrocytes and microglial cells, both, morphologically and on the level of gene expression. Enhancement of astroglial activation by treating OHSC with ciliary neurotrophic factor (CNTF accelerated the loss of neurogenesis, whereas treatment with indomethacin or an antagonist of the purinergic P2Y12 receptor exhibited potent protective effects on the neurogenic outcome. Therefore, we conclude that OHSC rapidly lose their neurogenic capacity due to persistent inflammatory processes taking place after the slice preparation. As inflammation is also considered to affect neurogenesis in many CNS pathologies, OHSC appear as a useful tool to study this interplay and its molecular basis. Furthermore, we propose that modification of glial activation might bear the therapeutic potential of enabling

  13. True Density Prediction of Garlic Slices Dehydrated by Convection.

    Science.gov (United States)

    López-Ortiz, Anabel; Rodríguez-Ramírez, Juan; Méndez-Lagunas, Lilia

    2016-01-01

    Physiochemical parameters with constant values are employed for the mass-heat transfer modeling of the air drying process. However, structural properties are not constant under drying conditions. Empirical, semi-theoretical, and theoretical models have been proposed to describe true density (ρp). These models only consider the ideal behavior and assume a linear relationship between ρp and moisture content (X); nevertheless, some materials exhibit a nonlinear behavior of ρp as a function of X with a tendency toward being concave-down. This comportment, which can be observed in garlic and carrots, has been difficult to model mathematically. This work proposes a semi-theoretical model for predicting ρp values, taking into account the concave-down comportment that occurs at the end of the drying process. The model includes the ρs dependency on external conditions (air drying temperature (Ta)), the inside temperature of the garlic slices (Ti ), and the moisture content (X) obtained from experimental data on the drying process. Calculations show that the dry solid density (ρs ) is not a linear function of Ta, X, and Ti . An empirical correlation for ρs is proposed as a function of Ti and X. The adjustment equation for Ti is proposed as a function of Ta and X. The proposed model for ρp was validated using experimental data on the sliced garlic and was compared with theoretical and empirical models that are available in the scientific literature. Deviation between the experimental and predicted data was determined. An explanation of the nonlinear behavior of ρs and ρp in the function of X, taking into account second-order phase changes, are then presented.

  14. Microelectrode arrays of diamond-insulated graphitic channels for real time detection of exocytotic events from cultured chromaffin cells and slices of adrenal glands

    CERN Document Server

    Picollo, F; Bernardi, E; Marcantoni, A; Pasquarelli, A; Carbone, E; Olivero, P; Carabelli, V

    2016-01-01

    A microstructured graphitic 4x4 multielectrode array was embedded in a single crystal diamond substrate (4x4 {uG-SCD MEA) for real-time monitoring of exocytotic events from cultured chromaffin cells and adrenal slices. The current approach relies on the development of a parallel ion beam lithographic technique, which assures the time effective fabrication of extended arrays with reproducible electrode dimensions. The reported device is suitable for performing amperometric and voltammetric recordings with high sensitivity and temporal resolution, by simultaneously acquiring data from 16 rectangularly shaped microelectrodes (20x3.5 um^2) separated by 200 um gaps. Taking advantage of the array geometry we addressed the following specific issues: i) detect both the spontaneous and KCl-evoked secretion simultaneously from several chromaffin cells directly cultured on the device surface, ii) resolve the waveform of different subsets of exocytotic events, iii) monitoring quantal secretory events from thin slices of ...

  15. Calcium scoring using 64-slice MDCT, dual source CT and EBT : a comparative phantom study

    NARCIS (Netherlands)

    Groen, Jaap M.; Greuter, Marcel J. W.; Vliegenthart, R.; Suess, C.; Schmidt, B.; Zijlstra, F.; Oudkerk, M.

    2008-01-01

    Purpose Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium de

  16. The Utility of Thin Slice Ratings for Predicting Language Growth in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Walton, Katherine M.; Ingersoll, Brooke R.

    2016-01-01

    Literature on "Thin Slice" ratings indicates that a number of personality characteristics and behaviors can be accurately predicted by ratings of very short segments (utility of Thin Slice ratings of young children with autism spectrum disorder for predicting developmental skills and…

  17. Effects of cryoprotectant addition and washout methods on the viability of precision-cut liver slices

    NARCIS (Netherlands)

    Guan, Na; van Midwoud, Paul M.; Blomsma, Sylvia; Fahy, Gregory M.; Groothuis, Geny M. M.; de Graaf, Inge A. M.

    2012-01-01

    Successful vitrification of organ slices is hampered by both osmotic stress and chemical toxicity of cryoprotective agents (CPAs). In the present study, we focused on the effect of osmotic stress on the viability of precision-cut liver slices (PCLS) by comparing different CPA solutions and different

  18. Performance Analysis of Generic vs.Sliced Tags in HepODBMS

    Institute of Scientific and Technical Information of China (English)

    KurtStockinger

    2001-01-01

    This paper presents a performance analysis of accessing tag data clustered in two different ways,namely event-wise clustering (generic tag)vs.attribute-wise clustering (sliced tag).The results show that especially "Prefetch-optimisation" results in an additional performance gain of sliced tags over generic tags when only a subset of all the tag attributes is accessed.

  19. Impairment-Aware Routing in Translucent Spectrum-Sliced Elastic Optical Path Networks

    NARCIS (Netherlands)

    Yang, S.; Kuipers, F.

    2012-01-01

    Spectrum-sliced elastic optical path (SLICE) technology offers a more flexible bandwidth allocation in optical networks than wavelength division multiplexing. It allows different connections to be served via different modulation formats. However, as with any optical network, the optical signal may b

  20. On the local existence of maximal slicings in spherically symmetric spacetimes

    CERN Document Server

    Cordero-Carrión, Isabel; Morales-Lladosa, Juan Antonio

    2010-01-01

    In this talk we show that any spherically symmetric spacetime admits locally a maximal spacelike slicing. The above condition is reduced to solve a decoupled system of first order quasi-linear partial differential equations. The solution may be accomplished analytical or numerically. We provide a general procedure to construct such maximal slicings.

  1. Sugar uptake and starch biosynthesis by slices of developing maize endosperm

    International Nuclear Information System (INIS)

    14C-Sugar uptake and incorporation into starch by slices of developing maize (Zea mays L.) endosperm were examined and compared with sugar uptake by maize endosperm-derived suspension cultures. Rates of sucrose, fructose, and D- and L-glucose uptake by slices were similar, whereas uptake rates for these sugars differed greatly in suspension cultures. Concentration dependence of sucrose, fructose, and D-glucose uptake was biphasic (consisting of linear plus saturable components) with suspension cultures but linear with slices. These and other differences suggest that endosperm slices are freely permeable to sugars. After diffusion into the slices, sugars were metabolized and incorporated into starch. Starch synthesis, but not sugar accumulation, was greatly reduced by 2.5 millimolar p-chloromercuribenzenesulfonic acid and 0.1 millimolar carbonyl cyanide m-chlorophenylhydrazone. Starch synthesis was dependent on kernel age and incubation temperature, but not on external pH (5 through 8). Competing sugars generally did not affect the distribution of 14C among the soluble sugars extracted from endosperm slices incubated in 14C-sugars. Competing hexoses reduced the incorporation of 14C into starch, but competing sucrose did not, suggesting that sucrose is not a necessary intermediate in starch biosynthesis. The bidirectional permeability of endosperm slices to sugars makes the characterization of sugar transport into endosperm slices impossible, however the model system is useful for experiments dealing with starch biosynthesis which occurs in the metabolically active tissue

  2. GA Based Test Case Generation Approach for Formation of Efficient Set of Dynamic Slices

    Directory of Open Access Journals (Sweden)

    Debasis Mohapatra

    2011-09-01

    Full Text Available Automated test case generation is an efficient approach for software testing. Slicing of program provides ease to testability and enhances debugging capacity. To generate the dynamic slice, slicing criterionis required in which the input data parameter is the essential component. Most of the research work focuses on deriving the input by random consideration but it simply takes a longest period of time to generate slices that provides the path coverage of Unit Under Test (UUT. This paper generates the optimal test cases by using Genetic Algorithm (GA and Control Flow Graph (CFG, these test cases cover all the independent path present in the CFG. The optimal test cases are supplied as input component of the dynamic slicing criteria. So the dynamic slice criteria that use these optimal test cases as the input generates the efficient dynamic slice set that is helpful in efficient testing and efficient debugging. Here two approaches, first the dynamic slice using node marking and the second by using relevant sets are discussed according to optimal test cases as input component.

  3. Hydrogel Embedding of Precision-Cut Liver Slices in a Microfluidic Device Improves Drug Metabolic Activity

    NARCIS (Netherlands)

    van Midwoud, Paul M.; Verweij, Niek; Groothuis, Geny M. M.; Verpoorte, Elisabeth; Merema, M.T.

    2011-01-01

    A microfluidic-based biochip made of poly(dimethylsiloxane) was recently reported for the first time by us for the incubation of precision-cut liver slices (PCLS). In this system, PCLS are continuously exposed to flow, to keep the incubation environment stable over time. Slice behavior in the biochi

  4. Ex-vivo evaluation of gene therapy vectors in human pancreatic (cancer) tissue slices

    Institute of Scientific and Technical Information of China (English)

    Michael A van Geer; Koert FD Kuhlmann; Conny T Bakker; Fibo JW ten Kate; Ronald PJ Oude Elferink; Piter J Bosma

    2009-01-01

    AIM: To culture human pancreatic tissue obtained from small resection specimens as a pre-clinical model for examining virus-host interactions.METHODS: Human pancreatic tissue samples (malignant and normal) were obtained from surgical specimens and processed immediately to tissue slices.Tissue slices were cultured ex vivo for 1-6 d in an incubator using 95% O2. Slices were subsequently analyzed for viability and morphology. In addition the slices were incubated with different viral vectors expressing the repor ter genes GFP or DsRed.Expression of these reporter genes was measured at 72 h after infection.RESULTS: With the Krumdieck tissue slicer, uniform slices could be generated from pancreatic tissue but only upon embedding the tissue in 3% low melting agarose. Immunohistological examination showed the presence of all pancreatic cell types. Pancreatic normal and cancer tissue slices could be cultured for up to 6 d, while retaining viability and a moderate to good morphology. Reporter gene expression indicated that the slices could be infected and transduced efficiently by adenoviral vectors and by adeno associated viral vectors, whereas transduction with lentiviral vectors was limited. For the adenoviral vector, the transduction seemed limited to the peripheral layers of the explants.CONCLUSION: The presented sys tem al lows reproducible processing of minimal amounts of pancreatic tissue into slices uniform in size, suitable for pre-clinical evaluation of gene therapy vectors.

  5. Application of an indirect immunofluorescent staining method for detection of Salmonella enteritidis in paraffin slices and antigen location in infected duck tissues

    Institute of Scientific and Technical Information of China (English)

    Bin Yan; An-Chun Cheng; Ming-Shu Wang; Shu-Xuan Deng; Zhen-Hua Zhang; Nian-Chun Yin; Ping Cao; Sheng-Yan Cao

    2008-01-01

    AIM:To detect Salmonella enteritidis (S.enteritidis)in paraffin slices and antigen location in infected duck tissues.METHODS:The rabbits were immunized with purified bacillus to obtain S.enteritidis-specific antibody,which were then extracted by the caprylic-ammonium sulphate method,purified through High-Q columns.An indirect immuno-fluorescent staining method (IFA) was established to detect the S.enteritidis antigen in paraffin slices.Detected S.enteritidis in each organ tissue of ducklings experimentally infected with S.enteritidis.RESULTS:The gland of Garder,heart,kidney,spleen,liver,brain,ileum,jejunum,bursa of Fabricius from S.enteritidis experimentally infected ducklings were positive or strongly positive,and the S.enteritidis antigen mainly distributed in the infected cell cytoplasm.CONCLUSION:IFA is an intuitioni/st,sensitive and specific method in detecting S.enteritidis antigen in paraffin wax slices,and it is a good method in diagnosis and antigen location of S.enteritidis.We also conclude that the gland of Garder,heart,kidney,spleen,liver,ileum,jejunum are target organs in S.enteritidis infections of duck,and S.enteritidis is an intracellular parasitic bacterium.

  6. Optimization of Brain T2 Mapping Using Standard CPMG Sequence In A Clinical Scanner

    Science.gov (United States)

    Hnilicová, P.; Bittšanský, M.; Dobrota, D.

    2014-04-01

    In magnetic resonance imaging, transverse relaxation time (T2) mapping is a useful quantitative tool enabling enhanced diagnostics of many brain pathologies. The aim of our study was to test the influence of different sequence parameters on calculated T2 values, including multi-slice measurements, slice position, interslice gap, echo spacing, and pulse duration. Measurements were performed using standard multi-slice multi-echo CPMG imaging sequence on a 1.5 Tesla routine whole body MR scanner. We used multiple phantoms with different agarose concentrations (0 % to 4 %) and verified the results on a healthy volunteer. It appeared that neither the pulse duration, the size of interslice gap nor the slice shift had any impact on the T2. The measurement accuracy was increased with shorter echo spacing. Standard multi-slice multi-echo CPMG protocol with the shortest echo spacing, also the smallest available interslice gap (100 % of slice thickness) and shorter pulse duration was found to be optimal and reliable for calculating T2 maps in the human brain.

  7. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Science.gov (United States)

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  8. Coronary artery imaging with 64-slice CT in atrial fibrillation patients: scanning method and post-processing techniques

    International Nuclear Information System (INIS)

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice CT in patient with atrial fibrillation. Methods: All the cardiac volume data of 31 patients with atrial fibrillation were reconstructed using absolute time method. The images of 12 patients. The images of 31 patients who undeiwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software.. The results of conventional coronary angiography (CAG) of the 10 patients were compared with CT coronary angiography. Results: The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 194(53.3%), 82(22.5%), 41(11.3%) and 47(12.9%) vessel segments. Comparison was carried out between CTA findings and CAG findings of the 125 segments of the coronary arteries in the 10 patients who underwent CAG. The sensitivity and specificity of CTA for diagnosing vessel with stenosis (≥ 50% narrowing) was 85%(17/20) and 95.2% (100/105). Conclusion: Coronary artery imaging using 64-slice CT is useful in patient with atrial fibrillation. (authors)

  9. Brain Basics

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    Full Text Available ... all. She was happily married and successful in business. Then, after a serious setback at work, she ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  10. Brain Basics

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    Full Text Available ... the anatomy, physiology, and chemistry of the nervous system. When the brain cannot effectively coordinate the billions ... basic working unit of the brain and nervous system. These cells are highly specialized for the function ...

  11. Brain Basics

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    Full Text Available ... the brain cannot effectively coordinate the billions of cells in the body, the results can affect many ... unit of the brain and nervous system. These cells are highly specialized for the function of conducting ...

  12. Brain Basics

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    Full Text Available ... Trials — Participants Statistics Help for Mental Illnesses Outreach Research Priorities Funding Labs at NIMH News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The ...

  13. Brain Basics

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    Full Text Available ... brain may play a role in disorders like schizophrenia or attention deficit hyperactivity disorder (ADHD) . Glutamate —the ... mental disorders, including autism , obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain Regions Just as many neurons ...

  14. Brain Basics

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    Full Text Available ... body, the results can affect many aspects of life. Scientists are continually learning more about how the brain grows and works in healthy people, and how normal brain development and function ...

  15. Brain Basics

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    Full Text Available ... Brain Basics will introduce you to some of this science, such as: How the brain develops How ... cell, and responds to signals from the environment; this all helps the cell maintain its balance with ...

  16. Brain Basics

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    Full Text Available ... How the brain develops How genes and the environment affect the brain The basic structure of the ... inside contents of the cell from its surrounding environment and controls what enters and leaves the cell, ...

  17. Brain Basics

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    Full Text Available ... affect many aspects of life. Scientists are continually learning more about how the brain grows and works ... early brain development. It may also assist in learning and memory. Problems in making or using glutamate ...

  18. Brain Basics

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    Full Text Available ... have been linked to many mental disorders, including autism , obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain ... studies show that brain growth in children with autism appears to peak early. And as they grow ...

  19. Brain Basics

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    Full Text Available ... may help improve treatments for anxiety disorders like phobias or post-traumatic stress disorder (PTSD) . Prefrontal cortex ( ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  20. Brain Basics

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    Full Text Available ... body, the results can affect many aspects of life. Scientists are continually learning more about how the brain grows and works in healthy people, and how normal brain development ...

  1. Brain Basics

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    Full Text Available ... medications could reduce the amount of trial and error and frustration that many people with depression experience ... early brain development, and may also assist in learning and memory. hippocampus —A portion of the brain ...

  2. Brain Diseases

    Science.gov (United States)

    The brain is the control center of the body. It controls thoughts, memory, speech, and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, ...

  3. Brain Basics

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    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ... depression experience when starting treatment. Gene Studies Advanced technologies are also making it faster, easier, and more ...

  4. Brain Basics

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    Full Text Available ... mainly involved in controlling movement and aiding the flow of information to the front of the brain, ... the neuron will fire. This enhances the electrical flow among brain cells required for normal function and ...

  5. Brain Basics

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    Full Text Available ... works in healthy people, and how normal brain development and function can go awry, leading to mental ... and are working to compare that with brain development in people mental disorders. Genes and environmental cues ...

  6. Brain Basics

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    Full Text Available ... and epigenetic changes can be passed on to future generations. Further understanding of genes and epigenetics may ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  7. Brain Basics

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    Full Text Available ... neurons, the most highly specialized cells of all, conduct messages. Every cell in our bodies contains a ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  8. Brain Basics

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    Full Text Available ... can be related to changes in the anatomy, physiology, and chemistry of the nervous system. When the ... healthy people, and how normal brain development and function can go awry, leading to mental illnesses. Brain ...

  9. Brain Basics

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    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... blues" from time to time. In contrast, major depression is a serious disorder that lasts for weeks. ...

  10. Design and Fabrication of a Hand Fed Motorized Oil Bean Slicing Machine

    Directory of Open Access Journals (Sweden)

    O. Oduma

    2016-09-01

    Full Text Available A hand fed African oil bean slicing machine which would be affordable, simple to operate and easy to maintain by local and/or small scale farmers and processors was designed and fabricated with locally available materials. The design was based on the engineering standard and specifications. Factors such as physical and mechanical properties of oil bean seeds, mechanical properties of construction materials, mach inability or deformability of construction materials, wear resistance, availability of power and cost of materials were considered in the fabrication of the device. 1hp electric motor powered the machine. The machine was tested for performance and it recorded an efficiency of 96.64% with minimal damage of the product. The bill of engineering measurement and evaluation revealed that the machine was fabricated at a total cost of ₦91,353.00. The device match the need of the oil bean processors and with adequate maintenance and/or management, it would ameliorate the difficulties involved in oil bean processing and, therefore boost the farmers’ production

  11. Value of MRI with sliding multi-slice technique for staging ovarian carcinoma

    International Nuclear Information System (INIS)

    Objective: To analyze the technical characteristics of sliding multi-slice magnetic resonance imaging (SMS-MRI), and to evaluate the value of staging ovarian carcinoma by SMS-MRI. Methods: Pre-operative SMS-MRI of chest, abdomen and pelvis was performed on 15 patients with ovarian carcinoma. Sequences included TSE T2WI, SMS TIRM and fat-suppressed contrast-enhanced SMS FLASH. The SMS-MRI was analyzed and staged according to FIGO's classification by two radiologists. The location of tumor, local invasion of uterus and fallopian tube or other pelvic tissues, peritoneum metastasis, lymph node metastasis and distal metastasis were recorded. The results were compared with operative and pathological findings. Results: The pathological diagnosis was serous cystadenocarcinoma (9), mucinous cystadenocarcinoma (2), endometrioid carcinoma (2), clear cell carcinoma (1) and granular cell carcinoma (1) at stage II (2), stage III (10) and stage IV (3). The accuracy of SMS-MRI staging was 100% (15/15). The tumor location, involvement of uterus and fallopian tubes as well as distant metastasis were accurately demonstrated by SMS-MRI. Conclusion: SMS-MRI can be a faster one-stop examination with good image quality. SMS-MRI is an alternative imaging method of staging ovarian carcinoma. (authors)

  12. Neuroprotection Promoted by Guanosine Depends on Glutamine Synthetase and Glutamate Transporters Activity in Hippocampal Slices Subjected to Oxygen/Glucose Deprivation.

    Science.gov (United States)

    Dal-Cim, Tharine; Martins, Wagner C; Thomaz, Daniel T; Coelho, Victor; Poluceno, Gabriela Godoy; Lanznaster, Débora; Vandresen-Filho, Samuel; Tasca, Carla I

    2016-05-01

    Guanosine (GUO) has been shown to act as a neuroprotective agent against glutamatergic excitotoxicity by increasing glutamate uptake and decreasing its release. In this study, a putative effect of GUO action on glutamate transporters activity modulation was assessed in hippocampal slices subjected to oxygen and glucose deprivation (OGD), an in vitro model of brain ischemia. Slices subjected to OGD showed increased excitatory amino acids release (measured by D-[(3)H]aspartate release) that was prevented in the presence of GUO (100 µM). The glutamate transporter blockers, DL-TBOA (10 µM), DHK (100 µM, selective inhibitor of GLT-1), and sulfasalazine (SAS, 250 µM, Xc(-) system inhibitor) decreased OGD-induced D-aspartate release. Interestingly, DHK or DL-TBOA blocked the decrease in glutamate release induced by GUO, whereas SAS did not modify the GUO effect. GUO protected hippocampal slices from cellular damage by modulation of glutamate transporters, however selective blockade of GLT-1 or Xc- system only did not affect this protective action of GUO. OGD decreased hippocampal glutamine synthetase (GS) activity and GUO recovered GS activity to control levels without altering the kinetic parameters of GS activity, thus suggesting GUO does not directly interact with GS. Additionally, the pharmacological inhibition of GS activity with methionine sulfoximine abolished the effect of GUO in reducing D-aspartate release and cellular damage evoked by OGD. Altogether, results in hippocampal slices subjected to OGD show that GUO counteracts the release of excitatory amino acids, stimulates the activity of GS, and decreases the cellular damage by modulation of glutamate transporters activity.

  13. A Novel Approach for Transmission of 56 Gbit/s NRZ Signal in Access Network Using Spectrum Slicing Technique

    DEFF Research Database (Denmark)

    Spolitis, S.; Vegas Olmos, Juan José; Bobrovs, V.;

    2013-01-01

    We present the spectrum slicing and stitching concept for high-capacity low optics complexity optical access networks. Spectrum slicing and stitching of a 56 Gbit/s NRZ electrical signal is experimentally demonstrated for the first time....

  14. Brain Basics

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    Full Text Available ... pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah ... having trouble coping with the stresses in her life. She began to think of suicide because she ...

  15. Brain Basics

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

  16. Brain Aneurysm

    Science.gov (United States)

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  17. Specific accumulation of {sup 18}F-deoxyglucose in three-dimensional long-term cultures of human and rodent brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Hocke, C.; Prante, O.; Kuwert, T. [Clinic of Nuclear Medicine, Univ. of Erlangen-Nuernberg (Germany); Bluemcke, I.; Jeske, I. [Dept. of Neuropathology, Univ. of Erlangen-Nuernberg (Germany); Romstoeck, J. [Dept. of Neurosurgery, Univ. of Erlangen-Nuernberg (Germany); Stefan, H. [Dept. of Neurology, Univ. of Erlangen-Nuernberg (Germany)

    2007-07-01

    Aim: Organotypic slice cultures (OSC) of human brain specimens represent an intriguing experimental model for translational studies addressing, e.g., stem cell transplantation in neurodegenerative diseases or targeting invasion by malignant glioma ex vivo. However, long-term viability and phenomena of structural reorganization of human OSC remain to be further characterized. Here, we report the use of {sup 18}F-deoxyglucose (FDG) for evaluating the viability of brain slice preparations obtained either from postnatal rats or human hippocampal specimens. Methods: Anatomically well preserved human hippocampi obtained from epilepsy surgery and rat hippocampus slice cultures obtained from six day old Wistar rats were dissected into horizontal slices. The slices were incubated with FDG in phosphate buffered saline up to 1 h, either with or without supplementation of glucose at a concentration of 2.5 mg/ml. Radioactivity within the medium or slice cultures was measured using a gamma-counter. In addition, distribution of radioactivity was autoradiographically visualized and quantified as counts per mm{sup 2}. Results: In rat hippocampal slices, FDG accumulated with 1 300 000 {+-} 68 000 counts/mm{sup 2}, whereas the incorporation of the radioactive label in human slices was in the order of 1 500 000 {+-} 370 000 counts/mm{sup 2}. The elevation of glucose concentration within the medium led to a significant three-fold decrease of FDG accumulation in rat slices and to a 2.4-fold decrease in human specimens. Conclusions: FDG accumulated in organotypic brain cultures of human or rodent origin. FDG is thus suited to investigate the viability of OSC. Furthermore, these preparations open new ways to study the factors governing cerebral FDG uptake in brain tissue ex vivo. (orig.)

  18. Adaptive SLICE method: an enhanced method to determine nonlinear dynamic respiratory system mechanics

    International Nuclear Information System (INIS)

    The objective of this paper is to introduce and evaluate the adaptive SLICE method (ASM) for continuous determination of intratidal nonlinear dynamic compliance and resistance. The tidal volume is subdivided into a series of volume intervals called slices. For each slice, one compliance and one resistance are calculated by applying a least-squares-fit method. The volume window (width) covered by each slice is determined based on the confidence interval of the parameter estimation. The method was compared to the original SLICE method and evaluated using simulation and animal data. The ASM was also challenged with separate analysis of dynamic compliance during inspiration. If the signal-to-noise ratio (SNR) in the respiratory data decreased from +∞ to 10 dB, the relative errors of compliance increased from 0.1% to 22% for the ASM and from 0.2% to 227% for the SLICE method. Fewer differences were found in resistance. When the SNR was larger than 40 dB, the ASM delivered over 40 parameter estimates (42.2 ± 1.3). When analyzing the compliance during inspiration separately, the estimates calculated with the ASM were more stable. The adaptive determination of slice bounds results in consistent and reliable parameter values. Online analysis of nonlinear respiratory mechanics will profit from such an adaptive selection of interval size. (paper)

  19. Effect of Superheated Steam Treatment on Changes in Moisture Content and Colour Properties of Coconut Slices

    Directory of Open Access Journals (Sweden)

    Mah Sook Yun

    2015-03-01

    Full Text Available Drying is one of the methods to preserve the quality and prolong the shelf life of food. Coconut meat was sliced and dried using superheated steam oven at 140°C, 160°C and 180°C. Drying was carried out at different drying time (5, 10, 15, 20, 25 and 30 minutes. The effect of drying temperature and time on the moisture content and colour properties (L, a, b and BI of the coconut slices were studied. The temperature and time significantly (p < 0.05 affected the moisture loss and colour values of coconut slices during superheated steam drying. The moisture content decreased with increased drying temperature and time. The values of L decreased with drying temperature and time. The a and b value of coconut slice dried at 140°C decreased initially then increased with time. Coconut slices dried at 160°C had their a values increased up to 20 minutes then decreased and b values increased up to 20 minutes then fluctuated. The a and b values of coconut slices dried at 180°C showed fluctuation. BI values of coconut slices increased with increasing drying time and temperature.

  20. Prion pathogenesis is faithfully reproduced in cerebellar organotypic slice cultures.

    Directory of Open Access Journals (Sweden)

    Jeppe Falsig

    Full Text Available Prions cause neurodegeneration in vivo, yet prion-infected cultured cells do not show cytotoxicity. This has hampered mechanistic studies of prion-induced neurodegeneration. Here we report that prion-infected cultured organotypic cerebellar slices (COCS experienced progressive spongiform neurodegeneration closely reproducing prion disease, with three different prion strains giving rise to three distinct patterns of prion protein deposition. Neurodegeneration did not occur when PrP was genetically removed from neurons, and a comprehensive pharmacological screen indicated that neurodegeneration was abrogated by compounds known to antagonize prion replication. Prion infection of COCS and mice led to enhanced fodrin cleavage, suggesting the involvement of calpains or caspases in pathogenesis. Accordingly, neurotoxicity and fodrin cleavage were prevented by calpain inhibitors but not by caspase inhibitors, whereas prion replication proceeded unimpeded. Hence calpain inhibition can uncouple prion replication from its neurotoxic sequelae. These data validate COCS as a powerful model system that faithfully reproduces most morphological hallmarks of prion infections. The exquisite accessibility of COCS to pharmacological manipulations was instrumental in recognizing the role of calpains in neurotoxicity, and significantly extends the collection of tools necessary for rigorously dissecting prion pathogenesis.

  1. Fast Evaluation of Bounded Slice-Line Grid

    Institute of Scientific and Technical Information of China (English)

    Song Chen; Xian-Long Hong; She-Qin Dong; Yu-Chun Ma; Chung-Kuan Cheng; Jun Gu

    2004-01-01

    Bounded Slice-line Grid (BSG). is an elegant representation of block placement, because it is very intuitionistic and has the advantage of handling various placement constraints. However, BSG has attracted little attention because its evaluation is very time-consuming. This paper proposes a simple algorithm independent of the BSG size to evaluate the BSG representation in O(nloglogn) time, where n is the number of blocks. In the algorithm, the BSG-rooms are assigned with integral coordinates firstly, and then a linear sorting algorithm is applied on the BSG-rooms where blocks are assigned to compute two block sequences, from which the block placement can be obtained in O(n log log n) time. As a consequence, the evaluation of the BSG is completed in O(n log log n) time, where n is the number of blocks. The proposed algorithm is much faster than the previous graph-based O(n2) algorithm. The experimental results demonstrate the efficiency of the algorithm.

  2. Fully programmable spectrum sliced chirped microwave photonic filter.

    Science.gov (United States)

    Leitner, Peter; Yi, Xiaoke; Li, Liwei; Huang, Thomas X H

    2015-02-23

    A novel chirped microwave photonic filter (MPF) capable of achieving a large radio frequency (RF) group delay slope and a single passband response free from high frequency fading is presented. The design is based upon a Fourier domain optical processor (FD-OP) and a single sideband modulator. The FD-OP is utilized to generate both constant time delay to tune the filter and first order dispersion to induce the RF chirp, enabling full software control of the MPF without the need for manual adjustment. An optimized optical parameter region based on a large optical bandwidth >750 GHz and low slicing dispersion < ± 1 ps/nm is introduced, with this technique greatly improving the RF properties including the group delay slope magnitude and passband noise. Experimental results confirm that the structure simultaneously achieves a large in-band RF chirp of -4.2 ns/GHz, centre frequency invariant tuning and independent reconfiguration of the RF amplitude and phase response. Finally, a stochastic study of the device passband noise performance under tuning and reconfiguration is presented, indicating a low passband noise <-120 dB/Hz. PMID:25836442

  3. Strong optomechanical interactions in a sliced photonic crystal nanobeam

    CERN Document Server

    Leijssen, Rick

    2015-01-01

    Cavity optomechanical systems can be used for sensitive detection of mechanical motion and to control mechanical resonators, down to the quantum level. The strength with which optical and mechanical degrees of freedom interact is defined by the photon-phonon coupling rate $g_0$, which is especially large in nanoscale systems. Here, we demonstrate an optomechanical system based on a sliced photonic crystal nanobeam, that combines subwavelength optical confinement with a low-mass mechanical mode. Analyzing the transduction of motion and effects of radiation pressure we find a coupling rate $g_0$/2{\\pi} = 11.5 MHz, exceeding previously reported values by an order of magnitude. Using this interaction we detect the resonator's motion with a noise imprecision below that at the standard quantum limit, even though the system has optical and mechanical quality factors smaller than $10^3$. The broad bandwidth is useful for application in miniature sensors, and for measurement-based control of the resonator's motional s...

  4. Fiber optic biofluorometer for physiological research on muscle slices

    Science.gov (United States)

    Belz, Mathias; Dendorfer, Andreas; Werner, Jan; Lambertz, Daniel; Klein, Karl-Friedrich

    2016-03-01

    A focus of research in cell physiology is the detection of Ca2+, NADH, FAD, ATPase activity or membrane potential, only to name a few, in muscle tissues. In this work, we report on a biofluorometer using ultraviolet light emitting diodes (UV-LEDs), optical fibers and two photomultipliers (PMTs) using synchronized fluorescence detection with integrated background correction to detect free calcium, Ca2+, in cardiac muscle tissue placed in a horizontal tissue bath and a microscope setup. Fiber optic probes with imaging optics have been designed to transport excitation light from the biofluorometer's light output to a horizontal tissue bath and to collect emission light from a tissue sample of interest to two PMTs allowing either single excitation / single emission or ratiometric, dual excitation / single emission or single excitation / dual emission fluorescence detection of indicator dyes or natural fluorophores. The efficient transport of light from the excitation LEDs to the tissue sample, bleaching effects of the excitation light in both, polymer and fused silica-based fibers will be discussed. Furthermore, a new approach to maximize light collection of the emission light using high NA fibers and high NA coupling optics will be shown. Finally, first results on Ca2+ measurements in cardiac muscle slices in a traditional microscope setup and a horizontal tissue bath using fiber optic probes will be introduced and discussed.

  5. Thin slice three dimentional (3D reconstruction versus CT 3D reconstruction of human breast cancer

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2013-01-01

    Full Text Available Background & objectives: With improvement in the early diagnosis of breast cancer, breast conserving therapy (BCT is being increasingly used. Precise preoperative evaluation of the incision margin is, therefore, very important. Utilizing three dimentional (3D images in a preoperative evaluation for breast conserving surgery has considerable significance, but the currently 3D CT scan reconstruction commonly used has problems in accurately displaying breast cancer. Thin slice 3D reconstruction is also widely used now to delineate organs and tissues of breast cancers. This study was aimed to compare 3D CT with thin slice 3D reconstruction in breast cancer patients to find a better technique for accurate evaluation of breast cancer. Methods: A total of 16-slice spiral CT scans and 3D reconstructions were performed on 15 breast cancer patients. All patients had been treated with modified radical mastectomy; 2D and 3D images of breast and tumours were obtained. The specimens were fixed and sliced at 2 mm thickness to obtain serial thin slice images, and reconstructed using 3D DOCTOR software to gain 3D images. Results: Compared with 2D CT images, thin slice images showed more clearly the morphological characteristics of tumour, breast tissues and the margins of different tissues in each slice. After 3D reconstruction, the tumour shapes obtained by the two reconstruction methods were basically the same, but the thin slice 3D reconstruction showed the tumour margins more clearly. Interpretation & conclusions: Compared with 3D CT reconstruction, thin slice 3D reconstruction of breast tumour gave clearer images, which could provide guidance for the observation and application of CT 3D reconstructed images and contribute to the accurate evaluation of tumours using CT imaging technology.

  6. Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Juan; Sun, Gang; Yu, Bling Bing; Li, Min; Li, Guo Ying; Peng, Zhao Hui; Zhang, Xu Ping [Dept. of Medical Imaging, Jinan Military General Hospital, Jinan (China); Lu, Yang [Dept. of Radiology, University of Illinois College of Medicine, Illinois (United States)

    2012-11-15

    To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 {+-} 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 {+-} 0.01 mSv) (p < 0.001). 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.

  7. Cartography of high-dimensional flows: a visual guide to sections and slices.

    Science.gov (United States)

    Cvitanović, Predrag; Borrero-Echeverry, Daniel; Carroll, Keith M; Robbins, Bryce; Siminos, Evangelos

    2012-12-01

    Symmetry reduction by the method of slices quotients the continuous symmetries of chaotic flows by replacing the original state space by a set of charts, each covering a neighborhood of a dynamically important class of solutions, qualitatively captured by a "template." Together these charts provide an atlas of the symmetry-reduced "slice" of state space, charting the regions of the manifold explored by the trajectories of interest. Within the slice, relative equilibria reduce to equilibria and relative periodic orbits reduce to periodic orbits. Visualizations of these solutions and their unstable manifolds reveal their interrelations and the role they play in organizing turbulence/chaos.

  8. 鲤鱼肉脯的生产工艺%Processing Technology of Fish Slice

    Institute of Scientific and Technical Information of China (English)

    华萍

    2011-01-01

    Study on the processing technique of dried carp fish slice. The optimum conditions were determined by orthogonal test and several crucial steps in the processing of dried carp fish slice, including fish skin remoral by hot water immersion, fishy odor elimination, curing,drying and frying were optimized. Key word: carp; dried fish slice;processing technique%以鲤鱼为原料,研制鱼肉脯的加工工艺。采用正交实验优化产品配方及对鲤鱼去皮、脱腥、干制、油炸等条件进行选择。

  9. Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong Hoon; Goo, Hyun Woo; Yoon, Chong Hyun [University of Ulsan College of Medicine, Asan Medical Center, Ulsan (Korea, Republic of)

    2004-09-15

    In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.

  10. Development of a fixed abrasive slicing technique (FAST) for reducing the cost of photovoltaic wafers

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, F. (Crystal Systems, Inc., Salem, MA (United States))

    1991-12-01

    This report examines a wafer slicing technique developed by Crystal Systems, Inc. that reduces the cost of photovoltaic wafers. This fixed, abrasive slicing technique (FAST) uses a multiwire bladepack and a diamond-plated wirepack; water is the coolant. FAST is in the prototype production stage and reduces expendable material costs while retaining the advantages of a multiwire slurry technique. The cost analysis revealed that costs can be decreased by making more cuts per bladepack and slicing more wafers per linear inch. Researchers studied the degradation of bladepacks and increased wirepack life. 21 refs.

  11. Slice emittance measurement for photocathode RF gun with solenoid scanning and RF deflecting cavity

    Science.gov (United States)

    Li, Chen; Huang, WenHui; Du, YingChao; Yan, LiXin; Tang, ChuanXiang

    2011-12-01

    The radiation of high-gain short-wavelength free-electron laser depends on the slice transverse emittance of the electron bunch. This essay introduces the method of slice emittance measurement, and shows the brief setup of this experiment using the solenoid scanning and RF deflecting cavity at Tsinghua University. The preliminary experimental results show that the slice rms emittance of the electron bunch generated by photocathode RF gun has considerable variations along the bunch and is typically less than 0.55 mm mrad for the laser rms radius of 0.4 mm.

  12. Control of enzymatic browning in apple slices by using ascorbic acid under different conditions.

    Science.gov (United States)

    el-Shimi, N M

    1993-01-01

    Control of phenol oxidase activity in apple slices by the use of ascorbic acid at different pH values, temperature and time of incubation was investigated. The enzyme was almost inactivated at 1% and 1.5% ascorbic acid. Ascorbic acid solution (1%) caused a remarkable inhibition with the increasing acidity up to pH = 1. Heating treatments for apple slices dipped in 1% ascorbic acid caused a reduction of enzymatic browning, optimum temperature for inactivation of the enzyme was between 60-70 degrees C for 15 minutes. Increasing the time of dipping apple slices in 1% ascorbic acid solutions and at different pH values reduce phenolase activity.

  13. Excitatory and inhibitory pathways modulate kainate excitotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Casaccia-Bonnefil, P; Benedikz, Eirikur; Rai, R;

    1993-01-01

    In organotypic hippocampal slice cultures, kainate (KA) specifically induces cell loss in the CA3 region while N-methyl-D-aspartate induces cell loss in the CA1 region. The sensitivity of slice cultures to KA toxicity appears only after 2 weeks in vitro which parallels the appearance of mossy fib...... fibers. KA toxicity is potentiated by co-application with the GABA-A antagonist, picrotoxin. These data suggest that the excitotoxicity of KA in slice cultures is modulated by both excitatory and inhibitory synapses....

  14. Cartography of high-dimensional flows: A visual guide to sections and slices

    CERN Document Server

    Cvitanovic, Predrag; Carroll, Keith M; Robbins, Bryce; Siminos, Evangelos

    2012-01-01

    Symmetry reduction by the method of slices quotients the continuous symmetries of chaotic flows by replacing the original state space by a set of charts, each covering a neighborhood of a dynamically important class of solutions, qualitatively captured by a `template'. Together these charts provide an atlas of the symmetry-reduced `slice' of state space, charting the regions of the manifold explored by the trajectories of interest. Within the slice, relative equilibria reduce to equilibria and relative periodic orbits reduce to periodic orbits. Visualizations of these solutions and their unstable manifolds reveal their interrelations and the role they play in organizing turbulence/chaos.

  15. Software framework developed for the slice test of the ATLAS endcap muon trigger system

    CERN Document Server

    Komatsu, S; Ishida, Y; Tanaka, K; Hasuko, K; Kano, H; Matsumoto, Y; Yakamura, Y; Sakamoto, H; Ikeno, M; Nakayoshi, K; Sasaki, O; Yasu, Y; Hasegawa, Y; Totsuka, M; Tsuji, S; Maeno, T; Ichimiya, R; Kurashige, H

    2002-01-01

    A sliced system test of the ATLAS end cap muon level 1 trigger system has been done in 2001 and 2002 separately. We have developed an own software framework for property and run controls for the slice test in 2001. The system is described in C++ throughout. The multi-PC control system is accomplished using the CORBA system. We have then restructured the software system on top of the ATLAS online software framework, and used this one for the slice test in 2002. In this report we discuss two systems in detail with emphasizing the module property configuration and run control. (8 refs).

  16. Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay

    International Nuclear Information System (INIS)

    In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection

  17. Increasing the range accuracy of three-dimensional ghost imaging ladar using optimum slicing number method

    Science.gov (United States)

    Yang, Xu; Zhang, Yong; Xu, Lu; Yang, Cheng-Hua; Wang, Qiang; Liu, Yue-Hao; Zhao, Yuan

    2015-12-01

    The range accuracy of three-dimensional (3D) ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slicing number (OSN) is determined. According to the OSN, an improved 3D ghost imaging algorithm is proposed to increase the range accuracy. Experimental results indicate that the slicing number can affect the range accuracy significantly and the highest range accuracy can be achieved if the 3D ghost imaging system works with OSN. Project supported by the Young Scientist Fund of the National Natural Science Foundation of China (Grant No. 61108072).

  18. Direct mapping of 19F in 19FDG-6P in brain tissue at subcellular resolution using soft X-ray fluorescence

    OpenAIRE

    Poitry-yamate, Carole; Gianoncelli, A; Kourousias, G.; Kaulich, B; Lepore, Mario; Gruetter, Rolf; M. Kiskinova

    2013-01-01

    Low energy x-ray fluorescence (LEXRF) detection was optimized for imaging cerebral glucose metabolism by mapping the fluorine LEXRF signal of 19 F in 19 FDG, trapped as intracellular 19 F-deoxyglucose-6-phosphate ( 19 FDG-6P) at 1μm spatial resolution from 3μm thick brain slices. 19 FDG metabolism was evaluated in brain structures closely resembling the general cerebral cytoarchitecture following formalin fixation of brain slices and their inclusion in an epon matrix. 2-dimensional distribu...

  19. Microelectrode Arrays of Diamond-Insulated Graphitic Channels for Real-Time Detection of Exocytotic Events from Cultured Chromaffin Cells and Slices of Adrenal Glands.

    Science.gov (United States)

    Picollo, Federico; Battiato, Alfio; Bernardi, Ettore; Marcantoni, Andrea; Pasquarelli, Alberto; Carbone, Emilio; Olivero, Paolo; Carabelli, Valentina

    2016-08-01

    A microstructured graphitic 4 × 4 multielectrode array was embedded in a single-crystal diamond substrate (4 × 4 μG-SCD MEA) for real-time monitoring of exocytotic events from cultured chromaffin cells and adrenal slices. The current approach relies on the development of a parallel ion beam lithographic technique, which assures the time-effective fabrication of extended arrays with reproducible electrode dimensions. The reported device is suitable for performing amperometric and voltammetric recordings with high sensitivity and temporal resolution, by simultaneously acquiring data from 16 rectangularly shaped microelectrodes (20 × 3.5 μm(2)) separated by 200 μm gaps. Taking advantage of the array geometry we addressed the following specific issues: (i) detect both the spontaneous and KCl-evoked secretion simultaneously from several chromaffin cells directly cultured on the device surface, (ii) resolve the waveform of different subsets of exocytotic events, and (iii) monitoring quantal secretory events from thin slices of the adrenal gland. The frequency of spontaneous release was low (0.12 and 0.3 Hz, respectively, for adrenal slices and cultured cells) and increased up to 0.9 Hz after stimulation with 30 mM KCl in cultured cells. The spike amplitude as well as rise and decay time were comparable with those measured by carbon fiber microelectrodes and allowed to identify three different subsets of secretory events associated with "full fusion" events, "kiss-and-run" and "kiss-and-stay" exocytosis, confirming that the device has adequate sensitivity and time resolution for real-time recordings. The device offers the significant advantage of shortening the time to collect data by allowing simultaneous recordings from cell populations either in primary cell cultures or in intact tissues. PMID:27376596

  20. Brain glycogen

    DEFF Research Database (Denmark)

    Obel, Linea Lykke Frimodt; Müller, Margit S; Walls, Anne B;

    2012-01-01

    Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia....... In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies-it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic...... activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms...

  1. Detection of blebs and bullae in patients with primary spontaneous pneumothorax by multi-detector CT reconstruction using different slice thicknesses

    International Nuclear Information System (INIS)

    The aim of this study was to compare the diagnostic performances of multi-detector computed tomography (MDCT) reconstruction at two different slice thicknesses (1mm, 'high resolution' vs. 5mm, 'routine') with respect to the detection of blebs and bullae (BBs) in patients with primary spontaneous pneumothorax (PSP). Thirty-one patients underwent wedge resection of BBs (29 unilateral and 2 bilateral) for PSP from January 2010 to January 2013. Two observers assessed the presence and locations of BBs independently using high-resolution CT (HRCT) and routine CT reconstruction, and compared the sensitivities of each reconstruction method for BB detection using operative findings as a standard reference. In addition, the number of BBs in each CT image set was recorded and inter-observer agreements were evaluated. Sensitivity for the detection of BBs was significantly better for HRCT than routine CT (97.0% vs. 63.6% for observer 1 and 94.0% vs. 57.6% for observer 2, respectively, both P-values<0.001). On a per-bleb and a per-bulla basis, inter-observer agreements regarding BBs by HRCT were good and very good (k=0.66 and 0.94, respectively) and superior to those determined by routine CT (k=0.59 and 0.60, respectively). Different slice thickness reconstructions influence the diagnostic efficacy of MDCT for the detection of BBs in patients with PSP. High-resolution thin slice CT reconstruction was found to have a significantly greater sensitivity than routine thicker slice thickness reconstruction for the detection of BBs.

  2. Effects of nicotine stimulation on spikes, theta frequency oscillations, and spike-theta oscillation relationship in rat medial septum diagonal band Broca slices

    Institute of Scientific and Technical Information of China (English)

    Dong WEN; Ce PENG; Gao-xiang OU-YANG; Zainab HENDERSON; Xiao-li LI; Cheng-biao LU

    2013-01-01

    Aim:Spiking activities and neuronal network oscillations in the theta frequency range have been found in many cortical areas during information processing.The aim of this study is to determine whether nicotinic acetylcholine receptors (nAChRs) mediate neuronal network activity in rat medial septum diagonal band Broca (MSDB) slices.Methods:Extracellular field potentials were recorded in the slices using an Axoprobe 1A amplifier.Data analysis was performed offline.Spike sorting and local field potential (LFP) analyses were performed using Spike2 software.The role of spiking activity in the generation of LFP oscillations in the slices was determined by analyzing the phase-time relationship between the spikes and LFP oscillations.Circular statistic analysis based on the Rayleigh test was used to determine the significance of phase relationships between the spikes and LFP oscillations.The timing relationship was examined by quantifying the spike-field coherence (SFC).Results:Application of nicotine (250 nmol/L) induced prominent LFP oscillations in the theta frequency band and both small-and large-amplitude population spiking activity in the slices.These spikes were phase-locked to theta oscillations at specific phases.The Rayleigh test showed a statistically significant relationship in phase-locking between the spikes and theta oscillations.Larger changes in the SFC were observed for large-amplitude spikes,indicating an accurate timing relationship between this type of spike and LFP oscillations.The nicotine-induced spiking activity (large-amplitude population spikes) was suppressed by the nAChR antagonist dihydro-β-erythroidine (0.3 μmol/L).Conclusion:The results demonstrate that large-amplitude spikes are phase-locked to theta oscillations and have a high spike-timing accuracy,which are likely a main contributor to the theta oscillations generated in MSDB during nicotine receptor activation.

  3. Climate model boundary conditions for four Cretaceous time slices

    Directory of Open Access Journals (Sweden)

    J. O. Sewall

    2007-06-01

    Full Text Available General circulation models (GCMs are useful tools for investigating the characteristics and dynamics of past climates. Understanding of past climates contributes significantly to our overall understanding of Earth's climate system. One of the most time consuming, and often daunting, tasks facing the paleoclimate modeler, particularly those without a geological background, is the production of surface boundary conditions for past time periods. These boundary conditions consist of, at a minimum, continental configurations derived from plate tectonic modeling, topography, bathymetry, and a vegetation distribution. Typically, each researcher develops a unique set of boundary conditions for use in their simulations. Thus, unlike simulations of modern climate, basic assumptions in paleo surface boundary conditions can vary from researcher to researcher. This makes comparisons between results from multiple researchers difficult and, thus, hinders the integration of studies across the broader community. Unless special changes to surface conditions are warranted, researcher dependent boundary conditions are not the most efficient way to proceed in paleoclimate investigations. Here we present surface boundary conditions (land-sea distribution, paleotopography, paleobathymetry, and paleovegetation distribution for four Cretaceous time slices (120 Ma, 110 Ma, 90 Ma, and 70 Ma. These boundary conditions are modified from base datasets to be appropriate for incorporation into numerical studies of Earth's climate and are available in NetCDF format upon request from the lead author. The land-sea distribution, bathymetry, and topography are based on the 1°×1° (latitude x longitude paleo Digital Elevation Models (paleoDEMs of Christopher Scotese. Those paleoDEMs were adjusted using the paleogeographical reconstructions of Ronald Blakey (Northern Arizona University and published literature and were then modified for use in GCMs. The paleovegetation

  4. Climate model boundary conditions for four Cretaceous time slices

    Directory of Open Access Journals (Sweden)

    J. O. Sewall

    2007-11-01

    Full Text Available General circulation models (GCMs are useful tools for investigating the characteristics and dynamics of past climates. Understanding of past climates contributes significantly to our overall understanding of Earth's climate system. One of the most time consuming, and often daunting, tasks facing the paleoclimate modeler, particularly those without a geological background, is the production of surface boundary conditions for past time periods. These boundary conditions consist of, at a minimum, continental configurations derived from plate tectonic modeling, topography, bathymetry, and a vegetation distribution. Typically, each researcher develops a unique set of boundary conditions for use in their simulations. Thus, unlike simulations of modern climate, basic assumptions in paleo surface boundary conditions can vary from researcher to researcher. This makes comparisons between results from multiple researchers difficult and, thus, hinders the integration of studies across the broader community. Unless special changes to surface conditions are warranted, researcher dependent boundary conditions are not the most efficient way to proceed in paleoclimate investigations. Here we present surface boundary conditions (land-sea distribution, paleotopography, paleobathymetry, and paleovegetation distribution for four Cretaceous time slices (120 Ma, 110 Ma, 90 Ma, and 70 Ma. These boundary conditions are modified from base datasets to be appropriate for incorporation into numerical studies of Earth's climate and are available in NetCDF format upon request from the lead author. The land-sea distribution, bathymetry, and topography are based on the 1°×1° (latitude × longitude paleo Digital Elevation Models (paleoDEMs of Christopher Scotese. Those paleoDEMs were adjusted using the paleogeographical reconstructions of Ronald Blakey (Northern Arizona University and published literature and were then modified for use in GCMs. The paleovegetation

  5. Influence of slice overlap on positron emission tomography image quality

    Science.gov (United States)

    McKeown, Clare; Gillen, Gerry; Dempsey, Mary Frances; Findlay, Caroline

    2016-02-01

    PET scans use overlapping acquisition beds to correct for reduced sensitivity at bed edges. The optimum overlap size for the General Electric (GE) Discovery 690 has not been established. This study assesses how image quality is affected by slice overlap. Efficacy of 23% overlaps (recommended by GE) and 49% overlaps (maximum possible overlap) were specifically assessed. European Association of Nuclear Medicine (EANM) guidelines for calculating minimum injected activities based on overlap size were also reviewed. A uniform flood phantom was used to assess noise (coefficient of variation, (COV)) and voxel accuracy (activity concentrations, Bq ml-1). A NEMA (National Electrical Manufacturers Association) body phantom with hot/cold spheres in a background activity was used to assess contrast recovery coefficients (CRCs) and signal to noise ratios (SNR). Different overlap sizes and sphere-to-background ratios were assessed. COVs for 49% and 23% overlaps were 9% and 13% respectively. This increased noise was difficult to visualise on the 23% overlap images. Mean voxel activity concentrations were not affected by overlap size. No clinically significant differences in CRCs were observed. However, visibility and SNR of small, low contrast spheres (⩽13 mm diameter, 2:1 sphere to background ratio) may be affected by overlap size in low count studies if they are located in the overlap area. There was minimal detectable influence on image quality in terms of noise, mean activity concentrations or mean CRCs when comparing 23% overlap with 49% overlap. Detectability of small, low contrast lesions may be affected in low count studies—however, this is a worst-case scenario. The marginal benefits of increasing overlap from 23% to 49% are likely to be offset by increased patient scan times. A 23% overlap is therefore appropriate for clinical use. An amendment to EANM guidelines for calculating injected activities is also proposed which better reflects the effect overlap size has

  6. USGS Small-scale Dataset - 100-Meter Resolution Color-Sliced Elevation of Hawaii 201303 TIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The map layer of Color-Sliced Elevation of Hawaii is a 100-meter resolution elevation image of Hawaii, in an Albers Equal-Area Conic projection. Each color tint...

  7. Preparation of organotypic hippocampal slice cultures for long-term live imaging.

    Science.gov (United States)

    Gogolla, Nadine; Galimberti, Ivan; DePaola, Vincenzo; Caroni, Pico

    2006-01-01

    This protocol details a method to establish organotypic slice cultures from mouse hippocampus, which can be maintained for several months. The cultures are based on the interface method, which does not require special equipment, is easy to execute and yields slice cultures that can be imaged repeatedly--from when they are isolated at postnatal day 6-9, and up to 6 months in vitro. The preserved tissue architecture facilitates the analysis of defined hippocampal synapses, cells and entire projections. Monitoring of defined cellular and molecular components in the slices can be achieved by preparing slices from transgenic mice or by introducing transgenes through transfection or viral vectors. This protocol can be completed in 3 h.

  8. An Experimental Investigation on the Drying of Sliced Food Products in Centrifugal Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    M.H.Shi; Y.L.Hao; 等

    1998-01-01

    An experimental investigation on the fluidization and drying characteristics of sliced food products in a centrifugal fluidized bed dryer was carried out,The rotaing speed ranges from 300 rpm to 500 rpm.Sliced potato and radish were used as the testing materials.The results show that the sliced materials can be fluidized well in the centrifugal fluidized bed.The fluidized curve has a maximum value and the critical fluidized velocities vary with the type of the test material,its shape and dimension as well as operating parameters.The sliced food materials can be dried very well and fast in the centrifugal fluidized bed with a large productivity.The factors that influence the drying process were examined and discussed.The final shape and inner structure of the dried products were observed.The water recovery characteristics of the drried products were also investigated.

  9. Hemodynamic study of hepatocellular car-cinoma nodules by multi-slice spiral computed tomographic perfusion

    Institute of Scientific and Technical Information of China (English)

    马国林

    2013-01-01

    Objective To analyze the 64-slice computed tomographic(CT) perfusion parameters of hepatocellular carcinoma(HCC) nodule so as to assess the diagnostic value of hemodynamic changes of HCC nodule by this perfusion

  10. Diagnostic Value of 16 Slices Spiral-CT for Portal Vein Disorders

    Institute of Scientific and Technical Information of China (English)

    李震; 胡道予; 肖明

    2004-01-01

    Summary: The diagnostic value of 16-slices spiral computed tomography (CT) for portal vein disorders was evaluated. Forty-one patients were scanned by the 16-slices spiral-CT. The celiac trunk,portal vein and their branches were reconstructed by volume rendering (VR), multiplanar volume reconstruction (MPVR) and maximum intensity projection (MIP) technique, and the results were compared with digital subtraction angiography (DSA). VR, MPVR and MIP could display celiac trunk, portal vein, inferior vena cava and their branches and extent of portal vein-vena cava shunt,portal vein emboli and the fistula of hepatic artery-portal vein. The results from 16-slices CT were better than DSA and identical with pathologic ones. The vessel three-dimension reconstruction technique of 16-slices spiral CT is valuable for evaluating the portal systemic disorders.

  11. Pharmacological antagonism of the actions of group II and III mGluR agonists in the lateral perforant path of rat hippocampal slices.

    OpenAIRE

    Bushell, T.J.; Jane, D. E.; Tse, H. W.; Watkins, J C; Garthwaite, J.; Collingridge, G L

    1996-01-01

    1. An understanding of the physiological and pathological roles of metabotropic glutamate receptors (mGluRs) is currently hampered by the lack of selective antagonists. Standard extracellular recording techniques were used to investigate the activity of recently reported mGluR antagonists on agonist-induced depressions of synaptic transmission in the lateral perforant path of hippocampal slices obtained from 12-16 day-old rats. 2. The group III specific mGluR agonist, (S)-2-amino-4-phosphonob...

  12. A modified method of medullary slice preparation in adult rats%成年大鼠延髓薄片制备的改良方法

    Institute of Scientific and Technical Information of China (English)

    罗道枢; 朱玲; 陈涛; 黄汾生; 王玮; 李云庆

    2012-01-01

    Objective: To establish a suitable method to prepare medullary slice for patch-clamp recording study in adult rats. Methods: Using a modified syringe to blow the medulla oblongata and upper cervical cord specimen out of the vertebral canal. The medullary slices were prepared by horizontal cutting the specimen. Then spontaneous and evoked discharges of neurons in the caudal subnucleus of the spinal trigeminal nucleus ( Vc) were recorded with voltage patch-clamp. Results: The prepared specimen was smooth and neat. The medullary slices with horizontal cutting maintained good morphological structure. The neuronal activities, such as spontaneous excitatory postsynaptic currents and evoked paired-pulse depression in the Vc were also recorded with easy. Conclusion; This method was simple and quick. The morphological features and neuronal activities of the medullary slice were kept without any mechanical damage. It means that the method used in the present study is suitable for patch-clamp recording study in the Vc of the adult animal.%目的:建立一种适用于膜片钳记录研究的成年大鼠延髓薄片制备方法.方法:用改制的注射器将延髓和上颈髓段从离断的椎管中直接吹出;采用水平切的方式制备延髓薄片;记录三叉神经脊束核尾侧亚核(Vc)神经元的自发放电和诱发放电活动.结果:分离得到的延髓和上颈髓标本光滑完整;水平切的延髓薄片较好地保持了Vc的形态学结构和神经元活性,可较好地记录到Vc神经元自发的兴奋性突触后电流和诱发的双脉冲抑制活动.结论:本方法操作简单,取材快速,延髓薄片外形完整且能保持神经元活性,适用于成年大鼠Vc的膜片钳研究.

  13. The impact of dietary isoflavonoids on malignant brain tumors.

    Science.gov (United States)

    Sehm, Tina; Fan, Zheng; Weiss, Ruth; Schwarz, Marc; Engelhorn, Tobias; Hore, Nirjhar; Doerfler, Arnd; Buchfelder, Michael; Eyüpoglu, Iiker Y; Savaskan, Nic E

    2014-08-01

    Poor prognosis and limited therapeutic options render malignant brain tumors one of the most devastating diseases in clinical medicine. Current treatment strategies attempt to expand the therapeutic repertoire through the use of multimodal treatment regimens. It is here that dietary fibers have been recently recognized as a supportive natural therapy in augmenting the body's response to tumor growth. Here, we investigated the impact of isoflavonoids on primary brain tumor cells. First, we treated glioma cell lines and primary astrocytes with various isoflavonoids and phytoestrogens. Cell viability in a dose-dependent manner was measured for biochanin A (BCA), genistein (GST), and secoisolariciresinol diglucoside (SDG). Dose-response action for the different isoflavonoids showed that BCA is highly effective on glioma cells and nontoxic for normal differentiated brain tissues. We further investigated BCA in ex vivo and in vivo experimentations. Organotypic brain slice cultures were performed and treated with BCA. For in vivo experiments, BCA was intraperitoneal injected in tumor-implanted Fisher rats. Tumor size and edema were measured and quantified by magnetic resonance imaging (MRI) scans. In vascular organotypic glioma brain slice cultures (VOGIM) we found that BCA operates antiangiogenic and neuroprotective. In vivo MRI scans demonstrated that administered BCA as a monotherapy was effective in reducing significantly tumor-induced brain edema and showed a trend for prolonged survival. Our results revealed that dietary isoflavonoids, in particular BCA, execute toxicity toward glioma cells, antiangiogenic, and coevally neuroprotective properties, and therefore augment the range of state-of-the-art multimodal treatment approach. PMID:24898306

  14. Fetal Brain MRI

    Directory of Open Access Journals (Sweden)

    Ahmad Tahmasebpour

    2010-05-01

    Full Text Available MRI is a useful supplement to ultrasonography for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive ultrasonography abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI. "nThe database comprises MR images of a total of 26 fetuses (gestational age 22-23 weeks reformed be-cause of suspected abnormalities due to ultrasonic findings, family history or maternal illness and scanned on a 1.5T MR system using single-shot fast spin echo "SSFSE, HASTE" T2 sequence, slice thick-ness 3mm, no gap. "HASTE=fourier acquisition single shotturbospinecho". In the normal fetus the ventricular size or volume did not vary with the gestational age but cerebral and cerebellar volumes increase during the same period "Grossman et al." Diagnostic accuracy is about 48%. "OB/GYN news, Chicago". Today it is not necessary to use sedatives or muscle relaxants to control fetal movement "ultra-fast MRI techniques". Modified technique for 50% reduction in the time necessary to take MRI images of the fetal brain is dedicated by Kianosh Hosseinzadeh, by using a line of reference through the eyes "AJR 2005"."nOur fetuses are 22-23 weeks in gestational age, 26 in number and we found agenesis of corpus callosum, hydrocephaly, holoprosencephaly, mega-cisterna magna, occipital meningocele, Arnold Chiari malformation type 1, Dandy Walker syndrome and lissencephaly

  15. Dynamic Slicing: a Generic Analysis Based on a Natural Semantics Format

    OpenAIRE

    Gouranton, Valérie; Le Métayer, Daniel

    1998-01-01

    Slicing analyses have been proposed for different programming languages. Rather than defining a new analysis from scratch for each programming language, we would like to specify such an analysis once for all, in a language-independent way, and then specialise it for different programming languages. In order to achieve this goal, we propose a notion of natural semantics format and a dynamic slicing analysis format. The natural semantics format formalises a class of natural semantics and the an...

  16. Calcium scoring using 64-slice MDCT, dual source CT and EBT: a comparative phantom study

    OpenAIRE

    Groen, Jaap M.; Greuter, Marcel J. W.; Vliegenthart, R.; Suess, C.; Schmidt, B.; Zijlstra, F.; Oudkerk, M.

    2007-01-01

    Purpose Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium density. Methods and materials Three artificial arteries with inserted calcifications of different sizes and densities were scanned at rest (0 beats per minute) and at 50–110 beats per minute (bpm) w...

  17. Anticonvulsant-like actions of baclofen in the rat hippocampal slice.

    OpenAIRE

    Ault, B.; Nadler, J V

    1983-01-01

    1 The effects of baclofen were tested on epileptiform discharge in the rat hippocampal slice. Slices were superfused with bicuculline methiodide (100 microM) and maximal periods of afterdischarge were evoked by stimulating the Schaffer collateral-commissural pathway in area CA1, mossy fibres in area CA3 or perforant path fibres in the fascia dentata or by antidromic stimulation of CA1 pyramidal cells. 2 (-)-Baclofen attenuated the afterdischarge evoked by stimulating all three sets of fibres ...

  18. A Cascaded Incoherent Spectrum Sliced Transversal Photonic Microwave Filters-An Analysis

    OpenAIRE

    R. K. Jeyachitra; Dr.R.Sukanesh

    2010-01-01

    An analysis of the performance of a simple, incoherent spectrum sliced microwave photonic filter is presented. This filter structure is based on cascading of two incoherent fiber Fabry -Pérot filters as a slicing element of a broadband optical source. The filter performance is studied by measuring the overall Free Spectral Range, 3dB Bandwidth, Quality factor and Main Lobe to Sidelobe Suppression level for different modes of connecting the filter in cascadedconfiguration. Also simulation resu...

  19. Recurrent Fully Convolutional Neural Networks for Multi-slice MRI Cardiac Segmentation

    OpenAIRE

    Poudel, Rudra P K; Lamata, Pablo; Montana, Giovanni

    2016-01-01

    In cardiac magnetic resonance imaging, fully-automatic segmentation of the heart enables precise structural and functional measurements to be taken, e.g. from short-axis MR images of the left-ventricle. In this work we propose a recurrent fully-convolutional network (RFCN) that learns image representations from the full stack of 2D slices and has the ability to leverage inter-slice spatial dependences through internal memory units. RFCN combines anatomical detection and segmentation into a si...

  20. Re-use of Low Bandwidth Equipment for High Bit Rate Transmission Using Signal Slicing Technique

    DEFF Research Database (Denmark)

    Wagner, Christoph; Spolitis, S.; Vegas Olmos, Juan José;

    : Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates.......: Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates....