ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)

Нелинейная динамика и нейронаука

Sequential activity in neuronal ensembles with excitatory couplings

A new model of neurons like elements is suggested in the paper. The model is based on the generalized Lottka–Volterra model with excitatory coupling. The study is motivated by the fact that the excitatory couplings are the dominating type of interactions between neurons in the human brain. It is shown in the paper that there are two regimes exist in such ensemble of oscillators in dependence on the coupling between the elements: the regime with stable heteroclinical cycle and the regime with stable limit cycle.

Optimization of basis function set for model map reconstruction of short electroencephalogram tracings during epileptic seizure

The problem of compact mathematical model reconstruction of short electroencephalogram tracings during epileptic seizure is solved. This kind of model map can be useful in many applications, for example, in time series segmentation with following clustering of obtained fragments. Optimization methods are proposed as a solution. It is shown that application of optimization methods allows to obtain adequate model at that time decreasing number of modeling map basis functions.

Oscillatory media properties influence on excitation propagation

We study synchronization in ensembles of locally di?usive coupled Bonhoe?er–van der Pol oscillators. Individual elements frequencies in?uence on excitation propagation in one- and two-dimensional media is investigated. We show that excitation propagation speed depends on frequency mismatch between synchronization frequency and elements’ individual frequencies. Qualitative and quantitative results describing this e?ect are numerical modeling data and analytical research.

Method for detecting of two types of brain neural ensemble activity during sleep according to electroencephalographic records

Method for detecting of two di?erent types of sleep spindles on electroencephalogram was o?ered. High precision of this method was demonstrated; it can be used in neurophysiological research of regularity of appearing of di?erent patterns on electroencephalogram.

Calcium oscillations in astrocytes part 1 astrocyte as generator of calcium oscillations

Bifurcation mechanisms of oscillatory dynamics in a biophysical model of chemically excitable brain cells (astrocytes) were analyzed. In contrast to neuronal oscillators widely studied in nonlinear dynamics the astrocytes do not possess electrical excitability but capable to generate chemical oscillations which modulate neuronal signaling. Astrocyte dynamics is described by third-order system of ordinary di?erential equations derived from biophysical kinetics.

Calcium oscillations in astrocytes part 2 dynamics of interacting calcium oscillators

We investigated bifurcation mechanisms of oscillatory dynamics of interacting chemically excitable cells (astrocytes). In model of three interacting astrocytes we studied bifurcation transitions leading to generation of calcium oscillations induced by the intercellular di?usion. We analyzed basic mechanisms of limit cycle instabilities and destructions, typical transitions to chaotic oscillations and basic properties of intercellular synchronization.

Neuron-like dynamics in phase-locked loop

Use of phase-locked loop as a model of neuron-like element is discussed. Parameter space of the model is partitioned into areas of di?erent regimes speci?c for dynamics of real neurons. Bifurcation mechanisms of transitions between regimes are examined.

Subjective evaluation of semantically unlike objects during exchange transactions

The work is devoted to quantitative modelling of regularities in the subjective comparison of the significance of unlike material and mental objects which are of a substantial value for a man. It is assumed that each object is perceived by a man as a complex semantic stimulus characterized by subjective significance and a finite set of the features which are to be taken into account.

Activity synchronization of different neuron types in the columns of the cerebral visual cortex

The results of neurophysiological and modeling studies focused on activity synchronization among of different types of neurons and spike shape dynamics in two bistability transition states have been presented. In modeling study, spike duration range of «fast» or «slow» neurons recorded in neurophysiological experiments were simulated.

Cognitive neurodynamics two strategies navigation behavior of organisms

The conceptual model and computer simulations results of path integration in free­scalable nonlinear oscillator neural networks with even cyclic inhibition (ECI­networks) are discussed in this paper. To estimate the phase shifting under input impact the ECI­networks contain two subsystems namely reference and information ones. The population of reference (nonencoding) oscillatory units has significant role in generation and stabilization of numerous time scales despite it don’t assist directly in the phase pattern encoding of input signals.