Volume 479, Nº 1 (2018)

Chronotopography of atrial subepicardium depolarization has been studied in a rat model of alcoholic cardiomyopathy. Formation of independent sources of initial atrial activity has been detected in the right and left atria. These sources induced the formation of several depolarization fronts that propagated autonomously, and this can be regarded as the cause of atrial arrhythmia.

The mechanisms of interictal discharges (IID) were studied under the conditions of the 4-aminopyridine model of spontaneous epileptiform activity in surviving rat brain slice preparations. Addition of the agents blocking GABA and NMDA receptors failed to inhibit IID generation in the entorhinal cortex. A mathematical model of IID has been developed on the basis of the excitatory neuron interaction mediated by the AMPA receptor. Short-term synaptic depression and slow afterspike-hyperpolarization are the key factors required to terminate a single IID. The IID shape-determining factors have been identified. The experimental and model IID features correspond to each other.

The maternal impact on the early behavioral responses in pups was studied in cross-fostering experiments with the newborn Wistar rats (the primiparous females were fostering the pups born to the females parturiated for the second time and vise versa). The maternal experience had a significant influence on the function development in both pre- and postnatal periods. Specific features of prenatal ontogeny of pups born by experienced females resulted in further, more stable development of the early behavioral responses. In the postnatal period, the maternal experience determined synchronization of the behavioral responses, which promoted the formation of the functional systems important for the newborn survival.

After a water load in rats hyperhydration occurs and the secretion of oxytocin increases by the neurohypophysis. This increases the water diuresis, the water is quickly excreted by the kidney, and the recovery of osmotic homeostasis is accelerated.

The effect of the diterpene glycoside stevioside and high concentrations of heavy metals on the molecular heterogeneity of lectins was studied in seedlings of Kazanskaya 560 winter wheat cultivar. Stevioside induced the emergence of a new 45-kDa lectin. Cultivation of wheat seedlings in CdSO₄ and ZnSO₄ solutions resulted in the emergence of the protein with Mr = 88 kDa. We detected the presence of both lectins in seedlings during combined treatment with stevioside and heavy metals.

First data on morphological and mitochondrial variation in the long-tailed hamster Cricetulus longicaudatus is presented. In contrast to genetically monomorphic populations of Mongolia and Tuva, the northeastern part of the Qinghai–Tibetian Plateau was found to harbor several divergent mtDNA lineages. This pattern suggests a recent expansion of the long-tailed hamster to the northern part of its recent range, which started from Tibet, presumably, in the late Middle Pleistocene. Several populations from the northern edge of the species range were found to be morphologically but not genetically distinct. The apparent disagreement between genetic and morphological data can be explained by rapid morphological evolution in peripheral isolates.