Dmitry A Ignat'ev

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Differences in taste bud ultrastructure between active and low-temperature hibernation states were investigated in the Siberian ground squirrel, Citellus undulatus. Compared to active summer animals, taste bud volume and the morphology of the taste pore showed little change while an animal was hibernating. However, impressive differences were observed in(More)
A study was made at electron microscope level of changes in the three-dimensional (3-D) morphology of dendritic spines and postsynaptic densities (PSDs) in CA1 of the hippocampus in ground squirrels, taken either at low temperature during hibernation (brain temperature 2-4 degrees C), or after warming and recovery to the normothermic state (34 degrees C).(More)
The functional (synthetic) activity of blood lymphocytes and bone marrow haemopoietic cells in ground squirrels during the annual cycle as well as in hibernating and awaken animals in winter have been studied by fluorescent microspectrometry. The effect of ionizing radiation on animals in different functional states of the hibernation-arousal bout was(More)
It was supposed that the transitional period from euthermia to hibernation rather than the period of winter hibernation is optimal for the secretion of biologically active substances in rodent tissues. This hypothesis was tested in experiment. The maximal O2 consumption suppression was noted in mice after I. P. Injection of blood plasma from suslik Citellus(More)
The literature data and our own data on the synaptic plasticity and remodeling of synaptic organelles in the central nervous system are reviewed. Modern techniques of laser scanning confocal microscopy and serial thin sectioning for in vivo and in vitro studies of dendritic spines, including the relationship between morphological changes and the efficacy of(More)
Noradrenaline application on the cerebral cortex of rabbits leads to an increase of the level of spatial correlation of neocortical potentials. At low doses of noradrenaline, the amplitude of EPs in the visual cortex initially decreases and then increases. With increases of the noradrenaline dose, the amplitude of EPs continues to increase. Amplitude of the(More)
Heart rate (HR) of ground squirrel C. undulatus was studied in dependence of season, level of activity, physiological state and air temperature (T). In summer HR varies from 110-130 beat/min in sleep up to 420 beat/min at flight from danger. During winter hibernation HP was minimal (3-5 beat/min) at T 1-4 degrees C, the increase in T induced the growth of(More)
The ligand-binding characteristics (B(max) and K(D)) of alpha(1)- and beta(1)/beta(2)-adrenoceptors were investigated in membranes prepared from brown adipose tissue (BAT) of warm-acclimated, cold-acclimated, hibernating and arousing ground squirrels (Spermophillus undulatus) and hamsters (Mesocricetus auratus) by specific binding of [(3)H]prazosin and(More)
The intracerebroventricular injection of the peptides kyotorphin (KT), newkyotorphin (NKT), and Aps-Tyr (BS) changed rat behaviour. There was an increase in the rate of exploratory reactions, rearing, grooming, stereotypic scratching movements, yawning, stretching, hiccupping, sneezing. Similar effects had been earlier observed in rats after administration(More)
Intracerebroventricular administration of the peptides kyotorphin (Tyr-Arg), neokyotorphin (Thr-Ser-Lys-Tyr-Arg), and Asp-Tyr at doses of 4 and 8 μg altered the behavior of rats in a manner similar to that seen after similar administration of brain fractions from hibernating ground squirrels (Citellus undulatus), which contained these peptides: there were(More)