Spike Type Research Articles

Magnetoencephalography's higher sensitivity to epileptic spikes may elucidate the profile of electroencephalographically negative epileptic seizures

Video electroencephalography (EEG) plays an important role in judging whether a clinical spell is an epileptic seizure or paroxysmal event, but its interpretation is not always straightforward. If clinical events without EEG correlates are strongly suggestive of seizures, we usually regard these spells as epileptic seizures. However, the electric/magnetic physiological profile of EEG-negative epileptic seizures remains unknown. We describe a 19-year-old man known to have epileptic seizures, in which both magnetoencephalography (MEG)-unique and EEG/MEG spikes were seen. Both types of spikes originated from the same source, but the EEG/MEG spikes were of significantly higher magnitude than the MEG-unique spikes. Therefore, some epileptic seizures, even though generated identically to the MEG-positive seizures, could be EEG-negative because of their smaller magnitude.

Microwave burst with fine spectral structures in a solar flare on 2011 August 9

On August 9, 2011, there was an X6.9 flare event occurred near the west limb of solar disk. From the observation obtained by the spectrometer of the Chinese Solar Broadband Radio Spectrometer in Huairou (SBRS/Huairou) around the flare, we find that this powerful flare has only a short-duration microwave burst of about only 5 minutes, and during the short-duration microwave burst, there are several kinds of fine structures on the spectrogram. These fine structures include very short-period pulsations, millisecond spike bursts, and type III bursts. The most interesting is that almost all of the pulses of very short-period pulsation (VSP) are structured by clusters of millisecond timescales of spike bursts or type III bursts. And there exists three different kinds of frequency drift rates in the VSP: the frequency drift rates with absolute value of about 55 - 130 MHz s^{-1} in the pulse groups, the frequency drift rates with absolute value of about 2.91 - 16.9 GHz s^{-1} on each individual pulse, and the frequency drift rates with absolute value of about 15 - 25 GHz s$^{-1}$) at each individual spike burst or type III burst.

Evaluation of yield and its components in barley (Hordeum vulgare L.) genotypes differentiated for spike and kernel types

In order to avoid no desired crosses to combine four types of barley, the differential effect of spike type and grain on final yield and its components was studied in twelve genotypes at Duitama and Samaca (Boyaca, Colombia) in a split-plot design with four replications. An analysis of variance was practiced, locally, for each variable taking the mean genotype groups as a treatment and not an individual genotype. Differences among treatments were determined by a Least Significance Difference. Two-rowed barley genotypes gave a higher number of effective tillers (Samaca) and heavier kernels (Duitama, Samaca); while, six-rowed barley genotypes had a greater number of kernels/spike (Duitama, Samaca). Additionally, in Duitama, hull absent kernel barley genotypes produced a greater number of kernels/spike; but, hulled kernel barley genotypes gave heavier kernels. The row number x hull prevalence interaction only affected the kernels/spike number (Duitama). As for the yield of dry grain in Duitama, none of the sources of variation presented significant effects. With regard to the row number, this may be due to compensation between the yield components, some higher than others in one or another type, between the two-rowed and six-rowed barleys evaluated.

Analysis of Amperometric Spike Shapes to Release Vesicles

AbstractCarbon‐fiber amperometry is a real‐time analytical tool to detect vesicle release events from individual secretory cells. This study compared the spike events released in response to local or global depolarization. We describe each spike shape that regularly occurs, as well as those shapes of spikes that occur with less frequency, but reproducibly. We compare how frequently each type of spike occurs, and compare their amplitudes and kinetics to the commonly accepted spike release events. Analysis of the amperometric peaks typically discarded from single cell amperometry recordings may reveal unappreciated phenomena related to the release of secretory vesicles.

Spiking Neural P Systems with Several Types of Spikes

With a motivation related to gene expression, where enzymes act in series, somewhat similar to the train spikes traveling along the axons of neurons, we consider an extension of spiking neural P systems, where several types of “spikes" are allowed. The power of the obtained spiking neural P systems is investigated. Some further extensions are mentioned, such as considering a process of decay in time of the spikes

Study on Chromosome Aberrations of Crosses Between 3E Disomic Addition Line and 2C Addition Line

Thinopyrum elongatum, a wild relative of wheat, can be used as an excellent source of disease and abiotic stresses resistance and carries several useful traits, which have been transferred into wheat by interspecific hybridization. The most effective method of transferring the profitable genes of Th. elongatum into wheat is to induce chromosome recombination by the gametocidal system. In this study, cross, backcross and selfcross were performed between Chinese Spring-Th. elongatum 3E disomic addition line and Chinese Spring-Ae. cylindrica gametocidal chromosome 2C disomic addition line, and the gametocidal chromosome would induce chromosome breakages and aberrations. The chromosome counts of somatic cell and the observation of PMCs metaphase were performed in F2, BC1F1 and F1, F2 plants, respectively, the results showed that the gametocidal chromosome was functioning during the formation of gametes. The gametocidal chromosome 2C induced segregation for spike type in F2 and BC1F1 plants. Thus, the gametocidal chromosome 2C was demonstrated to be effective on transferring Th. elongatum 3E chromosome into wheat.

Mapping of Mutant Gene prbs Controlling Poly-Row-and-Branched Spike in Barley (Hordeum vulgare L.)

Abstract A row-type mutant of barley named poly-row-and-branched spike (prbs) was previously obtained from a two-rowed cultivar Pudamai-2 after treated by inflorescence soaking in maize total DNA solution. The mutant produces branched spikes with irregular multiple rows. Genetic analysis indicated that the mutant phenotype was caused by a recessive gene prbs, and the PRBS locus had a recessive epistatic effect on an independent locus (denoted as Vrsx) conferring the variation of two-rowed spike vs. six-rowed spike. This study aimed to map PRBS as well as Vrsx using simple sequence repeats (SSR) markers. We developed an F 2 population from a cross between the prbs mutant and a six-rowed cultivar Putianwudu for the gene mapping. As the two target loci interacted to result in a segregation ratio of two-rowed type:six-rowed type:prbs=9:3:4 in the population, we adopted a special strategy to map the two loci. PRBS was mapped between SSR markers HvLTPPB and Bmag0508A on the short arm of chromosome 3H, with distances of 24.7 and 14.3 cM to the two markers, respectively. Vrsx was mapped between SSR markers Bmag0125 and Bmag0378 on chromosome 2H, with distances of 6.9 and 15.3 cM to the two markers, respectively. This suggests that Vrsx should be the known locus Vrsl, which predominantly controls row-type variation in barley cultivars, and PRBS is a new locus related to the row type of spikes in barley.

Mathematical model for metabolic neuro-hemodynamic coupling

Via advances of measuring techniques, neuronal activities have been estimated in more detail. Especially, by using the fMRI method, the BOLD (Blood Oxygen Level Dependent) Signal, which is defined by the hemoglobin concentration in the blood vessel, shows various activities of neurons near the vessel. Such BOLD signals are described by the hemoglobin level, vessel volume, and blood vessel flow, which are determined via the Balloon model [1]. Otherwise, the oxygen and the glucose, which have the important role for the neuronal activity, are transported from the blood vessel to the neuron directly or indirectly through the astrocyte. So, in order to explain the contribution of neuronal activity to the alteration of BOLD signal, it has been needed to consider the metabolic pathway which describes the oxygen and glucose consumption process of the neuron and the astrocyte [2]. Here, for describing the relationship between the blood oxygen level and the neuronal activity, we introduce the mathematical model for the interactions among a neuron, astrocyte, and capillary. Especially, we adapt the two compartment neuron model, which constitutes somatic and dendritic parts, for observing the alteration of the BOLD signal depending on the various neuronal spike types [3], and investigate the sodium, ATP, lactate, glucose, oxygen concentrations in the neuron and astrocyte

Evolution of unsteady flow near rotor tip during stall inception

Previously the features of circumferential propagation of self-induced tip leakage flow unsteadiness for a low speed isolated axial compressor rotor in the authors’ laboratory were discovered and investigated via numerical simulation, which only occurs below a critical stable flow point that is close to but not yet at the stall limit. Further in this paper, the detailed investigation on evolution of tip leakage flow during the throttling process into spike rotating stall was conducted by adopting the valve-throttling model. During this process, the development of the circumferential propagation of tip leakage flow unsteadiness was especially focused on. According to the unsteady characteristics of pressure signals, the evolvement of compressor flow field can be classified into four stages. As compressor throttled, the oscillation frequency of self-induced unsteady tip leakage flow decreased gradually, and thus resulted in the decrease of its circumferential propagation speed. The circumferential propagation of self-induced tip leakage flow unsteadiness is closely related with rotating instability. When the forward spillage of tip leakage flow at the leading edge occurred, the spike type rotating stall was initiated. Its flow structures were given in the paper.

Screening of Tolerant Spring Barleys for Terminal Heat Stress: Different Importance of Yield Components in Barleys with Different Row Type

To comparing barleys with different spike type in terms of yield and substantial yield components under terminal heat stress, 12 spring barley genotypes were tested at two levels of sowing dates i.e., normal (5 Dec) and late sowing (20 Jan) during the years 2005-2007. The crop­ physiological status of plants was remarkably affected by terminal heat stress which ultimately reduced grain yield. Optimum Plant Height (PLH) of two types of barleys were about 90 and 80 cm under optimum and heat stress condition, respectively indicating that under heat stress, the genes for reduced height may have increased the portion of assimilate to grain rather than to the stem. Observed difference in yield of 2-row genotypes was primarily caused by heat-induced reduction of S m- 2 and GW, instead of reduction of G S-I, whereas in 6-row barleys, G S-1 has higher contribution to grain yield than GW. According to comparing genotypes and using stress indices, genotypes which have higher grain yield in both stress and optimum conditions, such as L6 and L8 were identified as heat-tolerant genotypes.

Distinct tachykinin NK(1) receptor function in primate nucleus tractus solitarius neurons is dysregulated after second-hand tobacco smoke exposure.

Second-hand tobacco smoke (SHS) exposure in children increases the risk of asthma and sudden infant death syndrome. Epidemiological and experimental data have suggested SHS can alter neuroplasticity in the CNS, associated with substance P. We hypothesized that exposure to SHS in young primates changed the effect of substance P on the plasticity of neurons in the nucleus tractus solitarius (NTS), where airway sensory information is first processed in the CNS. Thirteen-month-old rhesus monkeys were exposed to filtered air (FA, n= 5) or SHS (n= 5) for >6 months from 50 days of their fetal age. Whole-cell patch-clamp recordings were performed on NTS neurons in brainstem slices from these animals to record the intrinsic cell excitability in the absence or presence of the NK(1) receptor antagonist, SR140333 (3 µM). Neurons were electrophysiologically classified based on their spiking onset from a hyperpolarized membrane potential into two phenotypes: rapid-onset spiking (RS) and delayed-onset spiking (DS) types. In RS neurons, SR140333 reduced the spiking response, similarly in both FA- and SHS-exposed animals. In DS neurons, SR140333 almost abolished the spiking response in FA-exposed animals, but had no effect in SHS-exposed animals. The contribution of NK(1) receptors to cell excitability depended on firing phenotype of primate NTS neurons and was disrupted by SHS exposure, specifically in DS neurons. Our findings reveal a novel NK(1) receptor function in the primate brainstem and support the hypothesis that chronic exposure to SHS in children causes tachykinin-related neuroplastic changes in the CNS.

Functional circuitry of a unique cerebellar specialization: the valvula cerebelli of a mormyrid fish

The valvula cerebelli of the mormyrid electric fish is a useful site for the study of cerebellar function. The valvula forms a part of the electrosensory-electromotor system of this fish, a system that offers many possibilities for the study of sensory-motor integration. The valvula also has a number of histological features not present in mammals which facilitate investigation of cerebellar circuitry and its plasticity. This initial study characterizes the basic physiology and pharmacology of cells in the valvula using an in vitro slice preparation. Intrinsic properties and synaptic responses of Purkinje cells and other cell types were examined. We found that Purkinje cells fire a small narrow Na + spike and a large broad Ca 2+ spike, generated in the axon initial segment and dendritic-soma region, respectively. Purkinje cells respond to parallel fiber inputs with graded excitatory postsynaptic potentials (EPSPs) and to climbing fiber inputs with all-or-none EPSPs. Efferent cells, Golgi cells, and deep stellate cells all fire a single type of large narrow spike and respond only to parallel fiber inputs. Both parallel fiber and climbing fiber responses in Purkinje cells appear to be entirely mediated by AMPA-type glutamate receptors, whereas parallel fiber responses in efferent cells and stellate cells include AMPA and NMDA components. In addition, a strong synaptic inhibition was uncovered in both Purkinje cells and efferent cells in response to the focal stimulation of parallel fibers. Dual cell recordings indicate that deep stellate cells contribute at least partially to this inhibition. We conclude that despite its unique histology, the local functional circuitry of the mormyrid valvula cerebelli is largely similar to that of the mammalian cerebellum. Thus, what is learned concerning the functioning of the mormyrid valvula cerebelli may be expected to be informative about cerebellar function in general.

Induction of theta-frequency oscillations in the rat medial septal diagonal band slice by metabotropic glutamate receptor agonists

The aim of this study was to examine the role of metabotropic glutamate receptors (mGluR) in the generation of oscillatory field activity at theta frequency (4–12 Hz) in the medial septal slice prepared from rat brain. Bath application of mGluR agonists and antagonists showed that activation of mGluR1-type receptors produces persistent theta frequency oscillations in a dose-responsive manner. This activity, induced by the group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG), was reduced by ionotropic glutamate receptor antagonists and abolished by further addition of a GABAA receptor antagonist. However, addition of a GABAA receptor antagonist on its own converted the DHPG-induced oscillations to intermittent episodes of accentuated theta frequency activity following a burst. In a proportion of slices, DHPG induced large amplitude field population spiking activity (100–300 μV) which is correlated linearly with the field theta oscillations and is sensitive to glutamate receptor antagonists, suggesting a role of this type of spikes in theta generation induced by DHPG. These data demonstrate that DHPG-sensitive neuronal networks within medial septum generate theta rhythmic activity and are differentially modulated by excitatory and inhibitory ionotropic neurotransmissions.

Local spindling in thalamus during cortical slow oscillation

Event Abstract Back to Event Local spindling in thalamus during cortical slow oscillation P. Barthó1, A. Slézia1, F. Mátyás1, I. Ulbert2 and L. Acsády1* 1 Hung. Acad. Sci.,, Institute of Experimental Medicine, Hungary 2 Hung. Acad. Sci.,, Institute of Psychology, Hungary Despite being the main input and output of the neocortex, the relationship of thalamus during cortical oscillations is not yet fully explored. To investigate this, we performed simultaneous multiple single-unit recordings in rats under urethane anesthesia in the ventral posteromedial nucleus (VPM) and the S1 cortex with four-shank silicon probes. In the VPM two types of spikes were recorded. Wide spikes showed the characteristic burst pattern of relay cells, while narrow spikes fired longer and slower bursts and displayed asymmetric cross-correlograms with wide spikes. During thalamic spindle episodes the two types of spikes fired at different phases, wide spikes preceding narrow spikes by ~25 ms. Most of the VPM multiunit activity was organized into spindle episodes, which only occasionally coincided with cortical spindles. These thalamic spindles were usually restricted to one or two electrode shanks. Both types of units were phase locked to spindles. Considering that VPM contains only relay cells, we propose that narrow spikes belong to axon terminals originating in the nRt. To prove this, we performed simultaneous juxtacell recording of the nRt soma, and axon terminal in VPM. Our data show that network activity in VPM is organized into spatially restricted spindle episodes, indicating that cortical control over VPM is not very, and VMP-nRt interaction dominates instead. Keywords: Neurophysiology, Neuroscience Conference: 13th Conference of the Hungarian Neuroscience Society (MITT), Budapest, Hungary, 20 Jan - 22 Jan, 2011. Presentation Type: Abstract Topic: Neurophysiology Citation: Barthó P, Slézia A, Mátyás F, Ulbert I and Acsády L (2011). Local spindling in thalamus during cortical slow oscillation. Front. Neurosci. Conference Abstract: 13th Conference of the Hungarian Neuroscience Society (MITT). doi: 10.3389/conf.fnins.2011.84.00093 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Mar 2011; Published Online: 23 Mar 2011. * Correspondence: Dr. L. Acsády, Hung. Acad. Sci.,, Institute of Experimental Medicine, Budapest, Hungary, acsady@koki.hu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers P. Barthó A. Slézia F. Mátyás I. Ulbert L. Acsády Google P. Barthó A. Slézia F. Mátyás I. Ulbert L. Acsády Google Scholar P. Barthó A. Slézia F. Mátyás I. Ulbert L. Acsády PubMed P. Barthó A. Slézia F. Mátyás I. Ulbert L. Acsády Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A New Hardware-oriented Spiking Neuron Model Based on SET and Its Properties

In this paper, a new simple hardware-oriented spiking neuron model is proposed. It is mainly based on one of intrinsic features of single- electron transistor (SET)––Coulomb Oscillation. In fact, Coulomb Oscillation can be considered as current pulses under the gate's voltage, which is similar with the pulses of spiking neurons. Accordingly, the circuit structure of spiking neuron model has been designed. By simulation on the PSPICE, the proposed new model can show different spiking types according to the different input signals and implement information encoding. The model can exhibit the property of synchronization. Unlike traditional neuron model, the proposed new model has the capacity of integrating both spatial and temporal signals. In addition the phase encoding is also involved. So the experiments’ results demonstrate that the model is an implement way of hardware-oriented spiking neuron models or even spiking neural networks (SNN).

Study on Screening of TaGA2ox1 Mutants in Wheat by Ion Beam Irradiation

As a kind of mutagen, ion beam irradiation can create abundant biological mutations. A population of about 2000 lines was generated by irradiating dry wheat seeds of Xiao Yan 81 with low-energy nitrogen ion beams. The traits of the plant, such as height, spike type, fertility, stem color and awn length, were investigated. The mutation rate in terms of the plant height in M2 was 2.9%. Eighteen deletion mutants of TaGA2ox1 were obtained. Associate analysis showed that TaGA2ox1 was closely related to the plant height. Most of the TaGA2ox1-deleted mutants were higher than the control, suggesting that the biological function of TaGA2ox1 is similar to its homologues in other plants. These results demonstrate that ion beam irradiation is an efficient tool in the construction of a mutant library for wheat.

Hippocampal spatial navigation: interneurons take responsibility

Hippocampal spatial navigation: interneurons take responsibility

Electrophysiological characteristics of cells in the anterior caudal lobe of the mormyrid cerebellum

We have examined the basic electrophysiology and pharmacology of cells in the anterior caudal lobe (CLa) of the mormyrid cerebellum. Intracellular recordings were performed in an in vitro slice preparation using the whole-cell patch recording method. The responses of cells to parallel fiber (PF) and climbing fiber (CF) stimulation and to somatic current injection were recorded, and then characterized by bath application of receptor and ion channel blockers. Using biocytin or neurobiotin, these cells were also morphologically identified after recording to ensure their classification. Efferent cells and two subtypes of Purkinje cells were identified on the basis of their physiology and morphology. While the majority of Purkinje cells fire a single type of spike that is mediated by Na +, some fire a large broad spike mediated by Ca 2+ and a narrow spike mediated by Na + at resting potential levels. By patching one recording electrode to the soma and another to one of the proximal dendrites of the same cell simultaneously, it was found that the Na + spike has an axonal origin and the Ca 2+ spike is generated in the soma-dendritic region of Purkinje cells. Efferent cells fire a single type of Na + spike only. Despite variations in their physiology and morphology, all cell types responded to PF stimulation with graded excitatory postsynaptic potentials (EPSPs) mediated by AMPA receptors. However, none of the efferent cells and only some of the Purkinje cells responded to CF activation with a large, AMPA receptor-mediated all-or-none EPSPs. We conclude that the functional circuitry of the CLa resembles that of other regions of the mormyrid cerebellum and is largely similar to that of the mammalian cerebellum.

Exercise training reduces dietary-induced activation and apoptosis of T cells in inguinal lymph nodes

A hybrid circuit of a transistor-based chip was implemented and characterized for the neuronal electrical activity recording. The integration of microfluidic architectures was developed to control precisely neurites outgrowth and form topologically defined and stable neural networks. Individual neural cells from rat retinae and Lymnaea stagnalis snails were immobilized on gates regions of Metal Insulator Semiconductor Field Effect Transistors (MISFET). Neuronal orientation was achieved in both cases but neuronal action potentials were only recorded in the L. stagnalis case. They were successfully triggered and inhibited by implementing a picrotoxin – GABA – picrotoxin injection protocol, exhibiting a direct influence of picrotoxin on the “spike type” action potential waveform. The implementation of the whole process of neuronal culture and subsequent activity monitoring constitutes a proof-of-principle experiment for the development of neuroelectronic systems for signal processing studies adapted to low-density neuronal cultures.

Numerical investigation of the unsteady tip leakage flow and rotating stall inception in a transonic compressor

It is well known that tip leakage flow has a strong effect on the compressor performance and stability. This paper reports on a numerical investigation of detailed flow structures in an isolated transonic compressor rotor-NASA Rotor 37 at near stall and stalled conditions aimed at improving understanding of changes in 3D tip leakage flow structures with rotating stall inception. Steady and unsteady 3D Navier-Stokes analyses were conducted to investigate flow structures in the same rotor. For steady analysis, the predicted results agree well with the experimental data for the estimation of compressor rotor global performance. For unsteady flow analysis, the unsteady flow nature caused by the breakdown of the tip leakage vortex in blade tip region in the transonic compressor rotor at near stall condition has been captured with a single blade passage. On the other hand, the time-accurate unsteady computations of multi-blade passage at near stall condition indicate that the unsteady breakdown of the tip leakage vortex triggered the short length-scale — spike type rotating stall inception at blade tip region. It was the forward spillage of the tip leakage flow at blade leading edge resulting in the spike stall inception. As the mass flow ratio is decreased, the rotating stall cell was further developed in the blade passage.