Nikita A. Shevchenko

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The effects of the neurotoxin kainic acid on a food-producing habit were studied in Wistar rats in an experimental chamber. Single doses of kainic acid at a subconvulsive dose (8 mg/kg, i.p.) were found to impair the habit, onset of impairment being delayed by several weeks rather than immediate. Conversely, administration of the neurotoxin at the(More)
Lipid composition of homogenate and neuronal and glial nuclei of the brain cortex of Wistar rats was studied under normal conditions and after seizures induced by injection of picrotoxin. Seizures increased contents of lysophosphatidylcholine, sphingomyelin, and total phospholipids in the homogenate. In neuronal nuclei contents of total phospholipids,(More)
Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal(More)
—A closed-form expression for a lower bound on the per soliton capacity of the nonlinear optical fibre channel in the presence of (optical) amplifier spontaneous emission (ASE) noise is derived. This bound is based on a non-Gaussian conditional probability density function for the soliton amplitude jitter induced by the ASE noise and is proven to grow(More)
Achievable information rates (AIRs) of wideband optical communication systems using a ∼40  nm (∼5  THz) erbium-doped fiber amplifier and ∼100  nm (∼12.5  THz) distributed Raman amplification are estimated based on a first-order perturbation analysis. The AIRs of each individual channel have been evaluated for DP-64QAM, DP-256QAM, and DP-1024QAM modulation(More)
—The channel law for amplitude-modulated solitons transmitted through a nonlinear optical fibre with ideal distributed amplification and a receiver based on the nonlinear Fourier transform is a noncentral chi distribution with 2n degrees of freedom, where n = 2 and n = 3 correspond to the single-and dual-polarisation cases, respectively. In this paper, we(More)
Learning and memory disorders accompanying epileptogenesis were studied in rats with the use of two experimental models of epilepsy, picrotoxin kindling and kainic treatment. Rise of exploratory activity and decrease in animal's capability for experimental extinction of a response were characteristic of the initial stage of epileptogenesis. It was suggested(More)
Effect of the neurotoxin kainic acid to the food-procuring task were studied in Wistar rats. A single injection of the acid in subconvulsive dose (8 mg/kg) impaired the task performance within some weeks but not immediately after the treatment. Higher doses of kainic acid (10 mg/kg) impaired the task performance within a few hours after treatment for up to(More)
Wistar rats were trained food-procuring task for 5 days and then extinction of the operant behavior was studied for 6 days after injection of an epileptogen (kainic acid, 8 mg/kg, intraperitoneally). Kainic acid induced long-term impairment of inhibitory processes in the brain, which impeded extinction of a conditioned response. This effect was prevented by(More)
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