Period-Adding Bifurcation with Chaos in the Interspike Intervals Generated by an Experimental Neural Pacemaker

1997 ◽  
Vol 07 (08) ◽  
pp. 1867-1872 ◽  
Author(s):  
W. Ren ◽  
S. J. Hu ◽  
B. J. Zhang ◽  
F. Z. Wang ◽  
Y. F. Gong ◽  
...  
Keyword(s):  
Neural Coding ◽  
Calcium Concentration ◽  
Channel Blocker ◽  
Interspike Interval ◽  
Surrogate Data ◽  
Nonlinear Phenomena ◽  
Chaotic Oscillations ◽  
Interspike Intervals ◽  
Excitable Cells ◽  
Nonlinear Forecasting

The dynamics of the generation of the various spike trains in neural pacemakers is of fundamental importance to the understanding of neural coding. Recent studies have demonstrated, theoretically and experimentally, that neural pacemakers produce chaotic oscillations. Deeper analyses in several neuronal models have revealed many nonlinear phenomena including period-adding bifurcations whose existence has not been experimentally confirmed. In this letter, we reported that the period-adding bifurcation with chaos was observed in the interspike interval (ISI) series generated by an experimental neural pacemaker when the extracellular calcium concentration was changed or a potassium channel blocker was administered at the site of the pacemaker. We also simulated our experimental discoveries by computing a generalized model of excitable cells. The chaotic phenomenon in the experiment and that in the model were demonstrated and compared using the nonlinear forecasting and surrogate data methods.

Bifurcation and Spike Adding Transition in Chay–Keizer Model

2016 ◽  
Vol 26 (05) ◽  
pp. 1650090 ◽  
Author(s):  
Bo Lu ◽  
Shenquan Liu ◽  
Xuanliang Liu ◽  
Xiaofang Jiang ◽  
Xiaohui Wang
Keyword(s):  
Bifurcation Analysis ◽  
Endocrine Cells ◽  
Signal Integration ◽  
Sequence Diagrams ◽  
Interspike Intervals ◽  
Excitable Cells ◽  
Bifurcation Phenomenon ◽  
Physiological Information ◽  
Value Changes ◽  
Parameter Bifurcation

Electrical bursting is an activity which is universal in excitable cells such as neurons and various endocrine cells, and it encodes rich physiological information. As burst delay identifies that the signal integration has reached the threshold at which it can generate an action potential, the number of spikes in a burst may have essential physiological implications, and the transition of bursting in excitable cells is associated with the bifurcation phenomenon closely. In this paper, we focus on the transition of the spike count per burst of the pancreatic [Formula: see text]-cells within a mathematical model and bifurcation phenomenon in the Chay–Keizer model, which is utilized to simulate the pancreatic [Formula: see text]-cells. By the fast–slow dynamical bifurcation analysis and the bi-parameter bifurcation analysis, the local dynamics of the Chay–Keizer system around the Bogdanov–Takens bifurcation is illustrated. Then the variety of the number of spikes per burst is discussed by changing the settings of a single parameter and bi-parameter. Moreover, results on the number of spikes within a burst are summarized in ISIs (interspike intervals) sequence diagrams, maximum and minimum, and the number of spikes under bi-parameter value changes.

Pattern Filtering for Detection of Neural Activity, with Examples from HVc Activity During Sleep in Zebra Finches

2003 ◽  
Vol 15 (10) ◽  
pp. 2307-2337 ◽  
Author(s):  
Zhiyi Chi ◽  
Peter L. Rauske ◽  
Daniel Margoliash
Keyword(s):  
Neural Coding ◽  
Point Processes ◽  
Statistical Significance ◽  
Test Procedure ◽  
Surrogate Data ◽  
Likelihood Ratios ◽  
Alignment Procedure ◽  
Auditory Evoked Response ◽  
The Individual ◽  
Spiking Activity

The detection of patterned spiking activity is important in the study of neural coding. A pattern filtering approach is developed for pattern detection under the framework of point processes, which offers flexibility in combining temporal details and firing rates. The detection combines multiple steps of filtering in a coarse-to-fine manner. Under some conditional Poisson assumptions on the spiking activity, each filtering step is equivalent to classifying by likelihood ratios all the data segments as targets or as background sequences. Unlike previous studies, where global surrogate data were used to evaluate the statistical significance of the detected patterns, a localizedp-test procedure is developed, which better accounts for firing modulation and nonstationarity in spiking activity. Common temporal structures of patterned activity are learned using an entropy-based alignment procedure, without relying on metrics or pair-wise alignment. Applications of pattern filtering to single, presumptive interneurons recorded in the nucleus HVc of zebra finch are illustrated. These demonstrate a match between the auditory-evoked response to playback of the individual bird's own song and spontaneous activity during sleep. Small temporal compression or expansion, or both, is required for optimal matching of spontaneous patterns to stimulus-evoked activity.

Analysis of Interspike Interval of Dorsal Horn Neurons Evoked by Different Needle Manipulations at St36

2014 ◽  
Vol 32 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Tao Zhou ◽  
Jiang Wang ◽  
Chun-Xiao Han ◽  
Ishida Torao ◽  
Yi Guo
Keyword(s):  
Firing Rate ◽  
Dorsal Horn ◽  
Neural Coding ◽  
Spinal Dorsal Horn ◽  
Interspike Interval ◽  
Dynamic Range ◽  
Stimulus Frequency ◽  
Electrical Signals ◽  
Spinal Dorsal ◽  
Wdr Neurons

Objectives Previous research has suggested that different manual acupuncture (MA) manipulations may have different physiological effects. Recent studies have demonstrated that neural electrical signals are generated or changed when acupuncture is administered. In order to explore the effects of different MA manipulations on the neural system, an experiment was designed to record the discharges of wide dynamic range (WDR) neurons in the spinal dorsal horn evoked by MA at different frequencies (0.5, 1, 2 and 3 Hz) at ST36. Methods Microelectrode extracellular recordings were used to record the discharges of WDR neurons evoked by different MA manipulations. Approximate firing rate and coefficient of variation of interspike interval (ISI) were used to extract the characteristic parameters of the neural electrical signals after spike sorting, and the neural coding of the evoked discharges by different MA manipulations was obtained. Results Our results indicated that the neuronal firing rate and time sequences of ISI showed distinct clustering properties for different MA manipulations, which could distinguish them effectively. Conclusions The combination of firing rate and ISI codes carries information about the acupuncture stimulus frequency. Different MA manipulations appear to change the neural coding of electrical signals in the spinal dorsal horn through WDR neurons.

scholarly journals Dynamical characteristics of magnetospheric energetic ion time series: evidence for low dimensional chaos

2003 ◽  
Vol 21 (9) ◽  
pp. 1995-2010 ◽  
Author(s):  
M. A. Athanasiu ◽  
G. P. Pavlos ◽  
D. V. Sarafopoulos ◽  
E. T. Sarris
Keyword(s):  
Time Series ◽  
Chaotic Dynamics ◽  
Lorenz System ◽  
Prediction Models ◽  
Surrogate Data ◽  
Nonlinear Phenomena ◽  
Energetic Ions ◽  
Dynamical Characteristics ◽  
Noise Perturbation ◽  
Low Dimensional

Abstract. This paper is a companion to the first work (Pavlos et al., 2003), which contains significant results concerning the dynamical characteristics of the magnetospheric energetic ions’ time series. The low dimensional and nonlinear deterministic characteristics of the same time series were described in Pavlos et al. (2003). In this second work we present significant results concerning the Lyapunov spectrum, the mutual information and prediction models. The dynamical characteristics of the magnetospheric ions’ signals are compared with corresponding characteristics obtained for the stochastic Lorenz system when a coloured noise perturbation is present. In addition, the null hypothesis is tested for the dynamical characteristics of the magnetospheric ions’ signal by using nonlinear surrogate data. The results of the above comparisons provide significant evidence for the existence of low dimensional chaotic dynamics underlying the energetic ions’ time series.Key words. Magnetospheric physics (energetic particles) – Radio sciences (nonlinear phenomena)

Dynamical Properties of Combustion Instability in a Laboratory-Scale Gas-Turbine Model Combustor

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Hiroshi Gotoda ◽  
Kenta Hayashi ◽  
Ryosuke Tsujimoto ◽  
Shohei Domen ◽  
Shigeru Tachibana
Keyword(s):  
Gas Turbine ◽  
Combustion Instability ◽  
Turbulent Flame ◽  
Surrogate Data ◽  
Permutation Entropy ◽  
Lean Blowout ◽  
Lean Premixed ◽  
Free Running ◽  
Nonlinear Forecasting ◽  
Turbine Model

We present an experimental study on the nonlinear dynamics of combustion instability in a lean premixed gas-turbine model combustor with a swirl-stabilized turbulent flame. Intermittent combustion oscillations switching irregularly back and forth between burst and pseudo-periodic oscillations exhibit the deterministic nature of chaos. This is clearly demonstrated by considering two nonlinear forecasting methods: an extended version (Gotoda et al., 2015, “Nonlinear Forecasting of the Generalized Kuramoto-Sivashinsky Equation,” Int. J. Bifurcation Chaos, 25, p. 1530015) of the Sugihara and May algorithm (Sugihara and May, 1990, “Nonlinear Forecasting as a Way of Distinguishing Chaos From Measurement Error in Time Series,” Nature, 344, pp. 734–741) as a local predictor, and a generalized radial basis function (GRBF) network as a global predictor (Gotoda et al., 2012, “Characterization of Complexities in Combustion Instability in a Lean Premixed Gas-Turbine Model Combustor,” Chaos, 22, p. 043128; Gotoda et al., 2016 (unpublished)). The former enables us to extract the short-term predictability and long-term unpredictability of chaos, while the latter can produce surrogate data to test for determinism by a free-running approach. The permutation entropy based on a symbolic sequence approach is estimated for the surrogate data to test for determinism and is also used as an online detector to prevent lean blowout.

Dihydropyridine-like effects of amiodarone and desethylamiodarone on thyrotropin secretion and intracellular calcium concentration in rat pituitary

1995 ◽  
Vol 133 (4) ◽  
pp. 489-498 ◽  
Author(s):  
Jean-Paul Roussel ◽  
Eric Grazzini ◽  
Michel Guipponi ◽  
Hélène Astier
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Channel Blocker ◽  
Primary Cultures ◽  
Biologically Active ◽  
Intracellular Calcium Concentration ◽  
Amiodarone Therapy ◽  
Pituitary Cells ◽  
Rat Pituitary ◽  
Intracellular Ca

Roussel J-P, Grazzini E, Guipponi M, Astier H. Dihydropyridine-like effects of amiodarone and desethylamiodarone on thyrotropin secretion and intracellular calcium concentration in rat pituitary. Eur J Endocrinol 1995;133:489–98. ISSN 0804–4643 Amiodarone (AM) and its major metabolite desethylamiodarone (DEA) are structurally similar to biologically active thyroid hormones. Amiodarone therapy is frequently associated with impairment of thyrotropic function, whose mechanisms are still controversial. Besides its effect on nuclear thyroid hormone binding, AM is able to displace dihydropyridine (DH) binding on membrane preparations from several tissues. By perifusing rat pituitary fragments and measuring thyrotropin (TSH) release we examined: the effect of AM on Ca2+-dependent and DHP-sensitive potentiation of the TSH response to thyrotropin-releasing hormone (TRH) induced by either triiodothyronine (T3, perifused for only 30 min before a TRH pulse) or by the prepro-TRH peptide 160–169 (PS4): and the effect of DEA on trh-induced TSH response in the presence or absence of the DHP nifedipine. We show that AM reverses T3 or PS4 potentiation of the TSH response to TRH; this effect is specific because AM does not modify does potentiation of that response. In contrast, DEA significantly potentiates the TSH response to TRH and the DHP nifedipine reverses that potentiation. We also tested whether Am would change the acute T3-induced increase in intracellular Ca2+ concentration by measuring intracellular Ca2+ ([Ca2+])i with fura-2 imaging on primary cultures of pituitary cells. We show that AM reverses the effect of T3 on [Ca2+]i as well as the PS4-induced increase in [Ca2+]i. In contrast, DEA increases [Ca2+]i and nifedipine reverses this effect. Our results suggest that AM and DEA display DHP-like effects on TRH-induced TSH release, behaving either as a Ca2+ channel blocker (AM) or as a Ca2+ channel agonist (DEA). H Astier, Laboratoire de Neurobiologie Endocrinologique, URA 1197 CNRS, Departement de Biologie-Santé Université de Montpellier 2, Place E. Bataillon, 34095 Montpellier Cedex 05, France

Precise Spatiotemporal Repeating Patterns in Monkey Primary and Supplementary Motor Areas Occur at Chance Levels

2000 ◽  
Vol 84 (4) ◽  
pp. 1770-1780 ◽  
Author(s):  
Stuart N. Baker ◽  
Roger N. Lemon
Keyword(s):  
Experimental Data ◽  
Firing Rate ◽  
Interspike Interval ◽  
Precision Grip ◽  
Surrogate Data ◽  
Spike Trains ◽  
Temporal Coding ◽  
Confidence Limits ◽  
Task Dependence ◽  
Repeating Patterns

Precise spatiotemporal patterns in neural discharge are a possible mechanism for information encoding in the brain. Previous studies have found that such patterns repeat and appear to relate to key behavioral events. Whether these patterns occur above chance levels remains controversial. To address this question, we have made simultaneous recordings from between two and nine neurons in the primary motor cortex and supplementary motor area of three monkeys while they performed a precision grip task. Out of a total of 67 neurons, 46 were antidromically identified as pyramidal tract neurons. Sections of recordings 60 s long were searched for patterns involving three or more spikes that repeated at least twice. The allowed jitter for pattern repetition was 3 ms, and the pattern length was limited to 192 ms. In all 11 recordings analyzed, large numbers of repeating patterns were found. To assess the expected chance level of patterns, “surrogate” datasets were generated. These had the same moment-by-moment modulation in firing rate as the experimental spike trains, and matched their interspike interval distribution, but did not preserve the precise timing of individual spikes. The number of repeating patterns in 10 randomly generated surrogates was used to form 99% confidence limits on the repeating pattern count expected by chance. There was close agreement between these confidence limits and the number of patterns seen in the experimental data. Analysis of high complexity patterns was carried out in four long recordings (mean duration 23.2 min, mean number of neurons simultaneously recorded 7.5). This analysis logged only patterns composed of a larger number (7–11) of spikes. The number of patterns seen in the surrogate datasets showed a small but significant excess over those seen in the original experimental data; this is discussed in the context of surrogate generation. The occurrence of repeating patterns in the experimental data were strongly associated with particular phases of the precision grip task; however, a similar task dependence was seen for the surrogate data. When a repeating pattern was used as a template to find inexact matches, in which up to half of the component spikes could be missing, similar numbers of matches were found in experimental and surrogate data, and the time of occurrence of such matches showed the same task dependence. We conclude that the existence of precise repeating patterns in our data are not due to cortical mechanisms that favor this form of coding, since as many, if not more, patterns are produced by spike trains constructed only to modulate their firing rate in the same way as the experimental data, and to match the interspike interval histograms. The task dependence of pattern occurrence is explicable as an artifact of the modulation of neural firing rate. The consequences for theories of temporal coding in the cortex are discussed.

scholarly journals Testing a neural coding hypothesis using surrogate data

2008 ◽  
Vol 172 (2) ◽  
pp. 312-322 ◽  
Author(s):  
Yoshito Hirata ◽  
Yuichi Katori ◽  
Hidetoshi Shimokawa ◽  
Hideyuki Suzuki ◽  
Timothy A. Blenkinsop ◽  
...  
Keyword(s):  
Neural Coding ◽  
Surrogate Data

Low Concentrations of Ouabain Increase Cytosolic Free Calcium Concentration in Rat Vascular Smooth Muscle Cells

1996 ◽  
Vol 90 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Zhiming Zhu ◽  
Martin Tepel ◽  
Marcus Neusser ◽  
Walter Zidek
Keyword(s):  
Calcium Concentration ◽  
Channel Blocker ◽  
Calcium Influx ◽  
Free Calcium ◽  
Concentration Increase ◽  
Cytosolic Free Calcium ◽  
Low Concentrations ◽  
Free Calcium Concentration ◽  
Cytosolic Free Calcium Concentration ◽  
Nanomolar Range

1. Low ouabain concentrations in the nanomolar range significantly increased cytosolic free calcium concentration. 2. The ouabain-induced cytosolic free calcium concentration increase was due to transplasmamembrane calcium influx, which could be prevented in the absence of extracellular calcium or by addition of the calcium channel blocker nifedipine. 3. The amount of stored cellular Ca2+, as determined by the thapsigargin-induced cytosolic free calcium concentration increase, was also enhanced by 1 nmol/l ouabain. 4. It is concluded that low ouabain concentrations affect intracellular cytosolic free calcium concentration homoeostasis.

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