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A N Radchenko

Publications and source records attributed to A N Radchenko.

10 recordsLinked to original sources
PubMedDate not supplied

[Effect of sizes of the retinal receptive field on the precision of image perception].

A paradox of sharp vision regardless of relatively large receptive fields of the retina is discussed. Transformation of images by the receptive fields or intersecting fields of vision of omma-tidia of the complex eye is described as an approximation of Bool functions by the implicant forms. Such an approximation results in the information compression. The compression coefficient is determined by the ratio between the implicants number and the number of points in the field of determination of the Bool function. The approximation errors strongly depend on the size of the receptive fields. With their increase the error abruptly decreases and only after passing the deep minimum it begins to slowly increase. The mechanism of information compression is a universal one and is similarly realized on the retina, facet and t.v. sets.

Humans↗
PubMedDate not supplied

[Hysteresis properties of excitable membranes--the basis for neuronal memory].

It is supposed that "fixed" membrane charges are spaced on protein lateral chain terminals and have limited ability to move with the chains. Interactions of the charges that are located on the opposite sides of the membrane depend on the membrane potential and can be described by a hysteresis volt-conformation characteristics with trigger transitions for one stable state to another. The value of the charges, that are shifted in the hysteresical loop limit, is close to the experimental data for gate currents. Possibility of interaction of chemoreceptive and electroexcitable mosaics of the neuron somato-dendrite membrane in eeg forming process is analysed.

Cell Membrane↗
PubMedDate not supplied

[Optimization of randomly organized distributive associative memory].

Sub- and intersynapsal randomly placed mosaics of somato-dendritical membrane are regarded as a neuronal memory system. The first (linear) subsystem seems as a mean for access (addressing) to the second (nonlinear, hysteresis) one. An informative model is created and optimal relations are detected on the threshold, geometrical and temporal parameters of the synapse fields. The relations being settled transform the synapse field to associative memory with optimal distributive features. The reliability of such memory is equal to one of the holograms.

Cell Membrane↗
PubMedDate not supplied

[Recording, consolidation, and reproduction of information in the neuronal memory].

The electroexcitable mosaic of neuron SD-membrane is considered to be a hysteresis medium: a set of bistable memory units (MU) that capture or give back the energy in state transitions. The consolidation is shown to be achieved by inactivation of a part of MU (which had lost their energy) by means of transit of their volt-conformative characteristics to the non-hysteresis form. The MU hysteresis features are the result of moderate mobility of the membrane charges. The consolidation results in immobilization of the charges. It seems that immobilization of gate charges is the same phenomenon. Great importance of time delay pertaining to this process is emphasized. The time delay and working point shift beyond the hysteresis loop limits into the hyperpolarization side ensures the non-destructive reading.

Cell Membrane↗
PubMedDate not supplied

[Role of the exterior geniculate bodies and superior colliculus in the system that collects and accumulates visual information].

An analysis of picture on- and off-decompositions by retina ganglion cells and ipsi- and contralateral projections interleaving in lateral geniculate bodies (LGB) layers lead to founding earlier unknown LGB function-the logic filtering of the accurate (common in two approximations) parts of images. On- and off-splitting guarantees non-depended picture over and below approximations and reliable performing the above filtering function in the LGB layers. System complementation to LGB function is retinotopic mapping of non-percept pixels. It relates to primary superior colliculus (SC) function. Correlation between LGB and SC functions and saccade eye movements is discussed. Neurological nets for LGB and for a part of SC which realize the specified processor functions are presented.

Geniculate Bodies↗
PubMedDate not supplied

[Effect of the mobility of gate charges on volt-ampere characteristics of excitable membranes].

An assumption on nature of the gate charges and known data on gate changes mobility allow to deduce the volt-ampere characteristics of ionic channels and the same for membrane. Model research shows that the volt-ampere curve shape depends on gate charges mobility. Its reduction and the followed gate charges immobilization during membrane excitation process are expressed as the changes of volt-ampere curves. These changes might be to specify as the fast components of the inactivation process. A number critical values of the gate charges mobility are calculated which are important for the functions of memory (hysteresis) and excitation (negative resistance). The coincidence of values of biased charge in model and experiment is noted. The formulae that are drown are compared with Hodgkin-Huxley approximations.

Electrochemistry↗