Volume 111, Nº 2 (2025)

The acute phase of ischemic stroke is accompanied by changes in the electrical activity of the cerebral cortex, reflecting the dynamics of pathophysiological processes in the damaged tissue. The first manifestation of ischemia is early depression of activity associated with a sharp suppression of synaptic transmission and an increase in the threshold of action potential generation. Further deterioration of the metabolic crisis in the tissue is marked by the emergence of waves of spreading depolarization (SD) – slow waves of mass depolarization of neurons and glial cells initiating in the area of the greatest deficit and spreading to the surrounding tissues. It has been shown that SDs are the main pathological mechanism causing growth of the ischemic focus, which makes them the most important target for therapeutic effects. In addition to SD, the development of a negative ultraslow potential (NUP) is observed, which is a high-amplitude (up to –100 mV) extracellular potential shift with extremely slow dynamics. It has been shown that the NUP occurs only in the area of developing damage, and its amplitude correlates with the size of the future ischemic damage. The mechanisms of NUP have not been fully studied to date. Both SD and NUP are highly informative markers of ischemic damage, but have extremely slow dynamics (frequency < 0.01 Hz), as a result they are not detectable when recorded in the classical EEG range (0.5–45 Hz). This review discusses the mechanisms underlying early depression of activity, and ultraslow SD and NUP signals in focal stroke, their importance for diagnostics and monitoring of the ischemic process, as well as modern therapeutic approaches to stroke management.

Hypertension is a serious disease characterized by a sustained or recurrent increase in blood pressure, which can lead to various complications. Here, we studied the effect of genetically determined arterial hypertension in rats on their adaptation to long-term isolation and subsequent response to acute restraint stress. Male SHR rats with spontaneous hypertension were maintained in individual cages for 14 weeks. The serum levels of corticosterone, glucose, and pro- and anti-inflammatory cytokines and salivary α-amylase activity were studied, and the expression of genes associated with the regulation of steroidogenesis in the adrenal glands was evaluated. There were no significant changes in the parameters of the hypothalamic-pituitary-adrenocortical and sympatho-adrenal systems after isolation. Nevertheless, the preliminary isolation significantly affected the response to moderate restraint stress, including the expression of the regulatory genes Fkbp5 and Star in the adrenal glands and the content of proinflammatory cytokines IL-1β and IL-6 in the blood, although the changes in these indices were relatively subtle. This may reflect the predisposition of animals in isolation to develop quite specific stress-related changes.

The study assessed the potential protective effect of empagliflozin (EMPA) on the functional state of various types of vessels in Wistar rats that received a single injection of the anthracycline antibiotic doxorubicin (DOX), used clinically as a chemotherapeutic agent for cancer. The rats were divided into 3 groups, 15 animals in each group. Rats in the DOX group were administered DOX (4 mg/kg) once, while animals in the DOX+EMPA group after a single administration of DOX (4 mg/kg) received EMPA (1 mg/kg) daily through a tube for 5 weeks. The control group consisted of intact animals. After 4 weeks of the experiment, the rats were examined for the initial skin microcirculation indices and their changes after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (NP) using Laser Doppler Flowmetry (LDF). One week after LDF, the mesenteric artery dilation value was analyzed by assessing the changes in vessel diameter before and after the action of ACh and NP, without blockers and under conditions of preliminary incubation of vessels with the NO synthase blocker L-NAME. In the control group rats, ACh iontophoresis caused an increase in perfusion intensity by 78.5%, in the DOX group the change was less pronounced (by 55.2%). EMPA prevented a decrease in the skin microvessel response to ACh, the perfusion index in rats of the DOX+EMPA group increased by 82.8%. The increase in the microcirculation index after NP iontophoresis in the DOX+EMPA group did not differ from the control, and in the DOX group it was significantly lower. ACh-induced dilation of the mesenteric arteries of the DOX group was 24.3% lower than in the control rats. The use of EMPA in rats that received DOX improved arterial reactivity. Compared with the reactivity of vessels without blockers, incubation of vessels with L-NAME reduced the amplitude of dilation under the action of ACh in all groups, but a less pronounced change was observed in the DOX group (45.6%). When using EMPA, the differences in the relaxation amplitude before and after NO synthase blockade increased (54.4%), but did not reach the control (64.1%). Conclusion. DOX leads to a decrease in the reactivity of various types of vessels to the action of vasodilators, in particular, ACh and NP. The use of EMPA has a protective effect in animals after the introduction of DOX, improving the dilation of the mesenteric arteries and vessels of the skin microcirculatory bed. It is possible that the effect of EMPA is associated with an improvement in the efficiency of NO-dependent vasorelaxation pathways, the disruption of which is observed upon the introduction of DOX.

Experiments were performed under urethane anesthesia on sexually mature non-pregnant female rats (n = 36). Pattern of electrical activity of the uterus in different phases of the estrous cycle, determined by the vaginal cytology (staining by Romanovsky dye), was studied. Electrohysterograms from the middle third of the left horn of the uterus were recorded using pressure bipolar electrodes. Increased excitability and conductivity of the uterus smooth myocytes occur during the stages of proestrus, estrus and metestrus, and their suppression is observed in diestrus. The maximum amplitude of motor potentials, compared to diestrus, was detected at the pro- (174 ± 17 μV) and metestrus (202 ± 20 μV) stages, while their mean frequency was high at the metestrus [4.4 (4.0; 5.0) Hz] and estrus [4.0 (4.0; 5.0) Hz)], exceeding those indicators for diestrus (86 ± 9 μV and 1.9 (1.3; 3.2) Hz approximately twice. Burst phase duration [40 (32; 50) and 36 (28; 47) s] of uterus periodic electrical activity had it maximum while rest period had it minimum [46 (40; 55) and 42 (26; 84) s] at proestrus and estrus stages which is also reflected in the high values of duty cycle – 0.46 (0.43; 0.50) and 0.45 (0.26; 0.63), respectively. Similar indicators for the diestrus stage were 27 (22; 32) and 80 (58; 124) s, 0.27 (0.18; 0.34). It is assumed that the highest excitability of the myometrium and its rhythmogenic areas during the metestrus stage, an increase in myometrium’s excitation conduction rate during proestrus and estrus, are due to an increase of electrical coupling between uterus smooth muscle cells.

The article is devoted to the study of neurophysiological correlates of art work (paintings) perception under the conditions of conscious (implicit) formation of the evaluative opinion about them. Participants (24 subjects, 18–60 years old, median 22.5 years, 6 male, 18 female) visited the exhibition of modern artists and in pairs viewed the paintings selected by each other and shared their opinions on the selected paintings. For each participant, the spectral powers of the EEG were compared in the states of «viewing your own choice» and «viewing the painting selected by the partner in the pair».

According to the EEG spectral analysis, a group of subjects can be divided into 2 subgroups, between which there were no differences when viewing a self-selected painting, but there were different reactions when viewing paintings that were chosen by a partner. In the first subgroup (14 people), lower power values (theta (4–8 Hz), alpha-1(8–10 Hz) and alpha-2 EEG bands) were obtained during perception of the own chosen painting while in the second subgroup (9 people), lower power values (in delta (1.6–4 Hz), theta (4–8 Hz), beta-1 (13.7–18 Hz) and beta-2 (13–30 Hz) EEG bands) were observed when viewing the paintings chosen by the partner. We can assume a difference in the strategies for evaluating a painting chosen by another person.

In the present work, 14 new diazepinebenzimidazole derivatives (DAB series) were screened for inhibitory activity against NMDA- and Ca^2+-impermeable (CI) AMPA-receptors. Experiments were conducted on isolated Wistar rat neurons; pyramidal neurons of the CA1 zone of the hippocampus were used to study NMDA- and CI-AMPA-receptors. Cell isolation was performed by vibrodissociation, and currents were recorded by whole-cell patch-clamp method. All the studied compounds at a concentration of 100 μM inhibited NMDA-receptors (≥30%), while CI-AMPA receptors currents were inhibited by only four compounds: DAB-8, DAB-12, DAB-19, and DAB-32. DAB-8, DAB-12 and DAB-32 have a 4-substituted phenacyl group at the nitrogen atom N¹¹ with an electronegative fluorine atom in the para position (DAB-8 and DAB-32) or without it (DAB-12), whereas the most active compound DAB-19 has a 4-tert-butyl-benzyl group at atom N¹¹ with a bulky tert-butyl substituent in the para position. The most active of them were DAB-12, DAB-19, and DAB-32, which were studied further for their IC₅₀ values. Compound DAB-19 demonstrated the most pronounced activity against both NMDA- and CI-AMPA-receptors: IC₅₀ values were 11,0 ± 1,6 µM and 15,4 ± 1,4 µM, respectively. Such an ability to inhibit both NMDA- and CI-AMPA-receptors at such concentrations is quite remarkable. Based on previous data on the neuropsychotropic effects of DAB-19, we put forward hypothesis about its possible anticonvulsant activity, which was confirmed in the "Pentylenetetrazol Seizure" test. The identification of DAB-19 as a combined antagonist of NMDA- and CI-AMPA-receptors is an important achievement for the further development of effective anticonvulsants.