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

Нелинейная динамика и нейронаука

Skin sensitivity: specificity of the dynamics of spatial­temporal patterns of activity of mechanoreceptors versus «labeled lines»

Through the development of methods for detecting the dynamics of spatial­temporal patterns of activity in the nervous system fundamental evidences obtained, that the sensory code have integrative nature and theories of localisation of function are inconsistent. The paper presents a review of electrophysiological data and models, indicating the integrative mechanisms of information coding in the peripheral skin analyzer of humans and animals.

Nonlinear dynamics of an expert,s thinking and algorithms of his professional knowledge expansion by example of medical problems

The process of a problem area experts knowledge acquisition is considered from a nonlinear dynamics positions. Stages and types of acquired knowledge are marked out; the role of an intuitive thinking in decision process concerning complex objects is defined. The role of intelligent data analysis methods in new knowledge forming processes is defined. The result of a developed «Semantic computer knowledge base analysis» algorithm is given on an example of the concrete medical problem.

Adaptive control signals of a mismatch in cognitive processes: the role of the endogenous opioid system

In the work we consider the classic cyclic schemes for the construction of cognitive processes. Based on neurobiological data we indicate the need to introduce a special mechanism for adaptive control signals of a mismatch in cognitive processes at the stage preceeding the decision point. Endogenous opioid system can be considered one of the major neurochemical candidates for such «breakers». This system provides the suppression of signals about a mismatch between current and target states of the cognitive system.

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.

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.

Sequential switching activity in the ensemble of nonidentical poincare systems ?

Switching activity in the ensemble of inhibitory coupled Poicare systems is considered. The existence of heteroclinic contour in the phase space at the certain domain of parameter space has shown. Dynamics of the ensemble of non-identical inhibitory and di?usively coupled systems of Poincare is considered. The approximate bifurcation diagrams for all qualitatively di?erent regimes of the network activity have shown.

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.

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.

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.