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Children are more likely to develop epileptic seizures (ictal discharges lasting tens of seconds) than adults. A higher predisposition of the juvenile brain to the generation of epileptiform activity is thought to be due to a prevalence of inhibition over excitation at the early stage of brain development. However, the molecular and physiological mechanisms underlying these age-related differences are yet to be clarified. We compared the ictal activity induced by a convulsant 4-aminopyridine (4-AP) in the horizontal slices of the entorhinal cortex and hippocampus of 3- and 8-week-old Wistar rats. In 3-week-old rats, the ictal discharge was always preceded by a detectable preictal activity, as manifested in one or several 3–4-s GABA-glutamate events, whereas in 8-week-old rats, such events were typically absent or very rare (no more than one occasional short event). The ictal activity resistance to external exposures was also age-dependent. In 8-week-old rats, by contrast to 3-week-old animals, ictal discharge generation in the entorhinal cortex was blocked completely and replaced by 0.2–0.3 Hz interictal activity (simultaneous 1–3-s burst discharges) by a partial blockade of KCC2 cotransporter or Na+–K+-pump, as well as by low-frequency electric stimulation. Thus, our data indicate that ictal discharges in the immature (3-week-old) brain are more resistant to external exposures than in the brain of adult rats. Interictal and ictal epileptiform activities are antagonistic in 8-week-old animals. In contrast, the appearance of interictal activity interrupts the generation of ictal discharges completely. It can therefore be considered as one of the putative antiepileptic mechanisms in the mature rat brain.

About one per cent of the world’s population suffers from epilepsy, and approximately 30% of cases fail to respond to medication. Novel approaches to treatment are required to help patients with drug-resistant epilepsy. One potential method consists of low-frequency stimulation of brain structures. However, at this time the mechanism of the anticonvulsant action of low-frequency stimulation is not completely understood. There are significant drawbacks to this method: it is invasive in nature and has nonspecific actions on brain tissues, which leads to various side effects. The development of optogenetics has provided a new impulse to studies of the mechanisms of action of low-frequency stimulation on epileptic activity. In addition, there is hope for significant reductions in the side effects of stimulation, as there is potential for selective activation or, conversely, inhibition of particular neuron populations. This review describes current progress in studies of the mechanisms of the generation and suppression of epileptic activity using an optogenetic method in in vitro and in vivo models of epilepsy. The potentials of this approach for clinical use are discussed.

One of the directions of development within the framework of the neuromorphic approach is the development of anatomically similar models of brain networks, taking into account the structurally complex structure of neurons and the adaptation of connections between them, as well as the development of learning algorithms for such models. In this work, we use the previously presented compartmental spike model of a neuron, which describes the structure (dendritic tree, soma, synapses) and behaviour (temporal and spatial signal summation, generation of action potential, stimulation and suppression of electrical activity) of a biological neuron. An algorithm for the structural organization of neuron models into a spike neural network is proposed for recognizing an arbitrary impulse pattern by introducing inhibitory synapses between trained neuron models. The dynamically adapting neuron models used are trained according to a previously proposed algorithm that automatically selects parameters such as soma size, dendrite length, and the number of synapses on each of the dendrites in order to induce a temporal response at the output depending on the input pattern encoded using a time window and temporal delays in the vector of single spikes arriving at a separate dendrite of a neuron. The developed algorithms are evaluated on the Iris dataset classification problem with four training examples from each class. As a result of the classification, separate disjoint clusters are formed, which demonstrates the applicability of the proposed spike neural network with a dynamically changing structure of elements in the problem of pattern recognition and classification.

The article presents an approach to using of visual location of an arbitrary number of known natural landmarks for correction of position estimation of a mobile robot. The approach is based on using of the Extended Kalman Filter to perform steps of the position prediction and correction based on the visual location. The visual location is performed using a calibrated camera (or a set of cameras) installed on the mobile robot. The task of a mobile robot navigation in a case of poorly determined conditions is often soled using a set of expensive LIDARs. Other sensors like GNSS and odometer often used in mobile robots are usually not precise enough (for example when maneuvering on intersections). The recent research in the field of computer vision allows creation of much less expensive systems based on image analysis from one or several cameras. When used together with other sensors such system can significantly increase the navigation precision and stability. Known visual navigation approaches like visual SLAM and visual odometer are often used but they are often not precise enough especially when the camera movement is mostly rotating. A set of one or more natural visual landmarks can be located automatically in real time using mobile robot cameras. Existing methods provide partial solutions for the position or direction estimation using 3 or more landmarks. The proposed approach is based on using of the Extended Kalman Filter for efficient fusion of the odometer and GNSS data with the visual location of one or more landmarks. Since all the landmarks are used one at a time independently the number of landmarks, cameras, their types and positions are arbitrary. The method is working with one camera and one landmark as well as with a round view camera system with one or many landmarks. Experiments involving autonomous driving through different intersections shown the feasibility of reaching of the accuracy of horizontal position of 10 cm and rotation of 1° and below. The method has been developed for improving of unmanned vehicles navigation at intersections but can be applied to navigation of different ground, space, marine and underwater mobile robots.

With the underwater human activity actively developing and the rise of the autonomous unmanned underwater vehicles (AUV) industry, researchers and engineers face the task of maintenance and repair of communications. For this purpose AUVs can be used, with e.g. the task of inspecting pipelines. The article describes the processing algorithm for the signal from passive ferromagnetic (fluxgate) sensors mounted on an AUV carrier used to search for metal-containing objects at the sea bottom. A scheme for such a measurement is proposed - the installation of two sensors at the opposite ends of the carrier. This allows to measure the gradient of magnetic field between the sensors. The characteristic form of such a signal and the dependence of the signal on the motion parameters of the vehicle and external factors are determined. To eliminate false positives, filters are used based on the readings of the position, speed and orientation sensors of the navigation system. Using data on the motion parameters of the device allows to generate a reference signal, which is used to validate the detection of an object using the cross-correlation method. The use of data on orientation angles makes it possible to compensate for the influence of the orientation of the device in the Earths magnetic field.

Annotation. In general, almost all fields of activities in the High North and the Arctic Region can be classified as either of high or extreme risks, as any kind of emergency at industrial site/object facility is very likely to lead to a large number of casualties. Rescuing people in distress is a complicated and challenging task. Having experience of numerous rescuing activities, it has shown that application of conventional rescue equipment in northern environments is not so effective: part of rescue facilities (such as medical aircrafts and ships) are based far from location of emergency, whereas the other part (floats, boats) have very limited capabilities. However, if arrived 48 hours after the catastrophe, there is almost zero possibility to find anyone alive, and the situation often becomes even worse because of the fact that rescuers have absolutely no idea about the actual situation and conditions within the emergency area or zone. Use of robotic groups in order to provide searching of survivors, lifting them up from either sea or ice surface, considering also further transporting of the people suffered - to stationary point-of-care or station of medical aid. Should tasks of robot group operation planning and of challenging situations complex analysis be considered, the most important is to implement standardized language with very clearly defined terminology. To solve this task, it is necessary to have appropriate ontology, i.e. it is ontology that determines core constructs, properties and connections. The article indicates core robotic ontologies, standardized and currently applied by international engineering community, as well as proposes extended solution of already existing IEEE standards (CORA, etc.), formulated with application of core SUMO ontology.

The detection of mutations of the gene of UDF-glucuronyltransferase A1 (UGT1A1) has an important practical value. The carriers of mutant genotypes, mainly *28/*28, are characterized by a reduced function of glucuronidation and excretion of a number of endogenous and exogenous toxins. A precise association of particular forms of benign hyperbilirubinemia (especially Gilbert's syndrome) with mutations in promoter and exonic areas of UGT1A1 is established. On the other hand, carriers of various genotypes of UGT1A1 differ significantly in metabolism characteristics of a number of common medications (irinotecan, belinostat, etc.), that requires a dosage of these medications considering individual genetic status of patient. The analysis of modern technical solutions for genetic diagnostics of UGT1A1 mutations is carried out. The particular attention is paid to discussion of national developments for genetic typing of UGT1A1. The conclusion is made concerning small assortment of corresponding test-systems of Russian production. In some cases, there is no data about their main analytical and diagnostic characteristics. When developing design of diagnosticums, various methodological approaches are applied that allow to potential consumers to choose depending on financial technical capabilities of laboratory, amount of implemented analyses, qualification of personnel. To support UGT1A1 research instrumentally, laboratory equipment of national manufacturers can be sufficient that would permit to organize entire analytical cycle on the basis of import substitution principle.

Currently, the task of developing the Arctic shelf is relevant, because there are proven reserves of minerals – oil and gas. Undoubtedly, researchers and engineers, after installing the appropriate underwater infrastructure, will face the task of maintenance and repair of communications. For this purpose, autonomous unmanned underwater vehicles (AUV) can be used, with e.g. the task of inspecting pipelines. The article describes the processing algorithm for the signal from passive ferromagnetic sensors mounted on an AUV carrier used to search for metal-containing objects at the sea bottom. A scheme for such a measurement is proposed - the installation of two sensors at opposite ends of the carrier. This allows to measure the gradient of magnetic field between the sensors. The characteristic form of such a signal and the dependence of the signal on the motion parameters of the vehicle and external factors are determined. To eliminate false positives, filters are used based on the readings of the position, speed and orientation sensors of the navigation system. Using data on the motion parameters of the device allows to generate a reference signal, which is used to validate the detection of an object using the cross-correlation method. The use of data on orientation angles makes it possible to compensate for the influence of the orientation of the device in the Earth’s magnetic field.

A hypercolumn of the visual cortex is a functional unit formed of neighboring columns whose neurons respond to a stimulus of particular orientation. The function of the hypercolumn is to amplify the orientation tuning of visually evoked responses. According to the conventional simple model of a hypercolumn, neuronal populations with different orientation preferences are distributed on a ring. Every population is described by a firing rate (FR) model. To determine the limitations of the FR-ring model, it was compared with a more detailed ring model, which takes into account the distribution of neurons of each population according to their voltage values. In the case of leaky integrate-and-fire neurons, every neuronal population is described by the Fokker-Planck equation (FPE). The mapping of parameters was obtained. The simulations revealed differences in the behavior of the two models. The FPE-based model reacts faster to a change in stimulus orientation. The FPE ring model gives a steady-state solution in the form of waves of activity traveling on the ring, whereas the FR ring model presents amplitude instability for the same parameter set. The FPE ring model reproduces the characteristic effects of the FR ring model: virtual rotation and symmetry breaking.

Changes in ionic permeability of bilayer lipid membranes (BLM) from dipalmitoyl phosphatidylcholine at temperature of phase transition in 1 M LiCl solution in the presence of polyethyleneglycols (PEG) of various molecular masses are studied. The transition of ionic membrane channels from conducting to blocked nonconducting state using polymers makes it possible to calibrate lipid pores. It is shown that low-molecular weight glycerol and PEG with molecular weights of 300 and 600 decrease the amplitude of current fluctuations through the membrane, the decrease being proportional to the size of the polymer molecule incorporated. The addition of PEG with molecular masses of 1450, 2000, and 3350 decrease the current fluctuations to the basal noise level. The result is considered as a complete blockade of ion channel conductivity. In the presence of rather large polymers, such as PEG with molecular masses of 6000 and 20000, which are hardly incorporated in the pore, single current fluctuations occur again; however, their amplitudes are somewhat smaller than in the absence of PEG. It is assumed that a complete blockade of the conductivity of lipid ionic channels by PEG with molecular masses of 1450, 2000, and 3350 is due to dehydration of the pore gap and the conversion of the hydrophilic pore to a hydrophobic one.

The activation of neurotransmitter receptors increases the current flow and membrane conductance and thus controls the firing rate of a neuron. In the present work, we justified the two-dimensional representation of a neuronal input by voltage-independent current and conductance and obtained experimentally and numerically a complete input-output (I/O) function. The dependence of the steady-state firing rate on the input current and conductance was studied as a two-parameter I/O function. We employed the dynamic patch clamp technique in slices to get this dependence for the whole domain of two input signals that evoke stationary spike trains in a single neuron (Ω-domain). As found, the Ω-domain is finite and an additional conductance decreases the range of spike-evoking currents. The I/O function has been reproduced in a Hodgkin-Huxley-like model. Among the simulated effects of different factors on the I/O function, including passive and active membrane properties, external conditions and input signal properties, the most interesting were: the shift of the right boundary of the Ω-domain (corresponding to the exCitation block) leftwards due to the decrease of the maximal potassium conductance; and the reduction of the Ω-domain by the decrease of the maximal sodium concentration. As found in experiments and simulations, the Ω-domain is reduced by the decrease of extracellular sodium concentration, by cooling, and by adding slow potassium currents providing interspike interval adaptation; the Ω-domain height is increased by adding color noise. Our modeling data provided a generalization of I/O dependencies that is consistent with previous studies and our experiments. Our results suggest that both current flow and membrane conductance should be taken into account when determining neuronal firing activity.

Characteristics of action potential generation are important to understanding brain functioning and, thus, must be understood and modeled. It is still an open question what model can describe concurrently the phenomena of sharp spike shape, the spike threshold variability, and the divisive effect of shunting on the gain of frequency-current dependence. We reproduced these three effects experimentally by patch-clamp recordings in cortical slices, but we failed to simulate them by any of 11 known neuron models, including one- and multi-compartment, with Hodgkin-Huxley and Markov equation-based sodium channel approximations, and those taking into account sodium channel subtype heterogeneity. Basing on our voltage-clamp data characterizing the dependence of sodium channel activation threshold on history of depolarization, we propose a 3-state Markov model with a closed-to-open state transition threshold dependent on slow inactivation. This model reproduces the all three phenomena. As a reduction of this model, a leaky integrate-and-fire model with a dynamic threshold also shows the effect of gain reduction by shunt. These results argue for the mechanism of gain reduction through threshold dynamics determined by the slow inactivation of sodium channels.