Photobiomodulation using low-intensity red light (LRL) is considered a safe, non-invasive, and cost-effective method that was proven to possess stimulating, restorative, and rejuvenating effects on body tissues. The therapeutic potential of photobiomodulation was demonstrated in various pathologies such as Alzheimer’s and Parkinson’s diseases and ischemic brain damage [1–3]. The potential photoacceptance of radiation by ETC’s complex IV (CIV) raises concern for the impact of LRL on mitochondria. However, ATP synthesis in mitochondria depends less on their functional state and more on the high electrical potential of coupled mitochondria. This study aimed to investigate the importance of photobiomodulation for the formation of brain mitochondria membrane potential in healthy mice and after hypoxia. Male C57BL/6 mice were used in the study. The animals were divided into two groups: a healthy control group (n=20) and a group of animals exposed to simulated hypobaric hypoxia (n=20). Half of the control animals (n=10) and half of the animals subjected to hypoxia modeling (n=10) received a single transcranial exposure of LRL (Spectr LC-02, Russia), which had a wavelength of 650±30 nm, for 3 minutes. After 24 hours, the mitochondrial fraction of the left cerebral cortex of the brain was isolated. The resulting fraction was used to examine how the mitochondrial membrane potential (ΔmtMP) dynamically changes by employing the O2k-Fluorescence LED2 amperometric module of the Oroboros Oxygraph-2k respirometer (Oroboros Instruments, Austria) and the fluorescent dye tetramethylrhodamine methyl ester. The collected data were normalized for protein content using the Bradford method. Statistical analysis was conducted with GraphPad Prism 8 and Excel. When investigating the impact of transcranial administration of LRL on ΔmtMP during CI-supported (CI, NADH-ubiquinone oxidoreductase) oxidative phosphorylation of the left cerebral cortex mitochondria in control animals, an increase of 18% was observed for the parameter. Further, a 40% increase was noted when studying CII-supported (CII, succinate dehydrogenase) oxidative phosphorylation compared to the untreated group. During the evaluation of basal respiration in the untreated control group, the measurement of ΔmtMP was 0.052±0.002 arb. units It was found that the transcranial application of LRL in mice caused a 2-fold increase of ΔmtMP (0.115±0.010 arb. units). Simulation of hypobaric hypoxia results in a 20% decrease in ΔmtMP during CI-supported oxidative phosphorylation but has no effect on ΔmtMP during CII-supported oxidative phosphorylation. Basal respiration after hypoxia modeling showed a 33% decrease in ΔmtMP compared to control values (0.052±0.002 arb. units and 0.035±0.003 arb. units, respectively). The transcranial administration of LRL following hypoxia modeling did not alter the dynamics of membrane potential during CI- and CII-supported oxidative phosphorylation, yet considerably amplified ΔmtMP when evaluating basal respiration. The transcranial LRL irradiation stimulated the healthy control group, resulting in an increase in ΔmtMP for both CI- and CII-supported oxidative phosphorylation and basal respiration. This increase in coupling between oxidation and phosphorylation processes was observed. However, after hypoxia modeling, the photobiomodulation effect of LRL was only observable under basal respiration conditions. The effects of the LRL application align with findings from other studies that suggest an elevation in ΔmtMP and the creation of ATP resulting from the dissociation of NO and the binuclear center of CIV [4].

Установлено, что однократное внутрибрюшинное введение циклофосфана в дозах 500, 750 и 1000 мг/кг приводит к развитию острого цитотоксического синдрома и высокой летальности среди экспериментальных животных. Полученные в ходе исследования результаты свидетельствуют, что общая и посуточная летальность, средняя продолжительность жизни, динамика веса и общее функционального состояние мышей имеют выраженный дозозависивый эффект. Развивающийся в ходе действия циклофосфана цитотоксический эффект сопровождался значительной отрицательной динамикой массы тела. В опытных группах наблюдали снижении массы тала мышей более чем в 1,5 раза при сравнении с исходными значениями и более чем в 2 раза при сравнении с контрольными группами. Тусклый и грязный цвет шерсти, признаки жидкого стула и аллопеции, снижении и отсутствие ориентировочно-исследовательских реакций, общей двигательной активности вплоть до потери позы свидетельствовали об отрицательной динамики общего функционального состояния мышей на фоне острого цитотоксическом действия циклофосфана. Начиная с 6 суток после введения циклофосфана в дозах 750 и 1000 мг/кг отмечали массовую гибель мышей, а к 14 суткам интоксикации летальность достигала 83,3 – 100%. При использовании циклофосфана в дозе 500 мг/кг летальность составила 70%. На основании полученных наблюдений можно сделать следующий вывод – данную экспериментальную модель целесообразно использовать для изучения механизмов цитотоксического действия циклофосфана с целью решения задач по устранению данного эффекта. It was found that a single intraperitoneal administration of cyclophosphane at doses of 500, 750 and 1000 mg / kg leads to the development of acute cytotoxic syndrome and high mortality among experimental animals. The results obtained during the study indicate that the total and daily mortality, average life expectancy, weight dynamics and general functional condition of mice have a pronounced dose-dependent effect. The cytotoxic effect developing during the action of cyclophosphane was accompanied by a significant negative dynamics of body weight. In the experimental groups, a decrease in the tala mass of mice was observed by more than 1.5 times when compared with the initial values and by more than 2 times when compared with the control groups. The dull and dirty color of the coat, signs of loose stools and allopecia, a decrease and absence of tentative research reactions, general motor activity up to the loss of posture testified to the negative dynamics of the general functional state of mice against the background of acute cytotoxic effects of cyclophosphane. Starting from 6 days after the introduction of cyclophosphane at doses of 750 and 1000 mg / kg, mass death of mice was noted, and by the 14th day of intoxication, mortality reached 83.3–100%. When using cyclophosphane at a dose of 500 mg / kg, the mortality rate was 70%. Based on the observations obtained, the following conclusion can be drawn – it is advisable to use this experimental model to study the mechanisms of cytotoxic action of cyclophosphane in order to solve problems to eliminate this effect.

The effectiveness of low-intensity red light on myofascial trigger points in skeletal muscle of mature rats was evaluated by electron microscopy and high-resolution respirometry. The revealed changes in mitochondrial ultrastructure and activity of the respiratory chain enzymes indicate the development of hypoxia in the simulation area. Under the influence of low-intensity red light on myofascial trigger points, a decrease in the number of destructively altered muscle fibers and stimulation of mitochondrial respiration were found. These findings indicate intracellular regeneration and the stimulating effect of low-intensity red light on plastic processes.

This research was aimed at investigating the features of free radical activity and the parameters of glutathione metabolism in tumor tissues and the peritumoral zone at different degrees of glial tumor anaplasia. We analyzed postoperative material from 20 patients with gliomas of different degrees of anaplasia. The greatest differences compared to adjacent noncancerous tissues were found in the tumor tissue: an increased amount of glutathione and glutathione-related enzymes at Grades I and II, and a decrease of these parameters at Grades III and IV. For the peritumoral zone of Grades I and II, the indices changed in different directions, while for Grades III and IV, they occurred synchronously with the tumor tissue changes. For Low Grade and High Grade gliomas, opposite trends were revealed regarding changes in the level of glutathione and the enzymes involved in its metabolism and in the free radical activity in the peritumoral zone. The content of glutathione and the enzymes involved in its metabolism decreased with the increasing degree of glioma anaplasia. In contrast, free radical activity increased. The glutathione system is an active participant in the antioxidant defense of the body and can be used to characterize the cell condition of gliomas at different stages of tumor development.

This research aimed to investigate the interrelationship of carbohydrate metabolism parameters and immunohistochemical characteristics of glial tumors. Tumor tissue, peritumoral area, and adjacent noncancerous tissue fragments of 20 patients with gliomas of varying degrees of anaplasia were analyzed. The greatest differences in the carbohydrate metabolism compared to adjacent noncancerous tissues were identified in the tumor tissue: reduction in the levels of lactate and glycogen synthase kinase-3β. Significant differences with adjacent noncancerous tissues for the peritumoral zone were not found. The activity of the carbohydrate metabolism enzymes was different depending on the immunohistochemical glioma profile, especially from Ki 67 level. Bioinformatic analysis of the interactions of immunohistochemical markers of gliomas and carbohydrate metabolism enzymes using the databases of STRING, BioGrid, and Signor revealed the presence of biologically significant interactions with glycogen synthase kinase 3β, hexokinase, glucose-6-phosphate dehydrogenase, and transketolase. The established interconnection of glycolysis with methylation of the promoter of O-6-methylguanine-DNA-methyltransferase (MGMT) of gliomas can be used to increase chemotherapy efficiency.

This research aimed to investigate the relationships between the parameters of glutathione metabolism and the immunohistochemical characteristics of glial tumors. Postoperative material from 20 patients with gliomas of different grades of anaplasia was analyzed. Bioinformatic analysis of the interactions between the gliomas’ immunohistochemical markers and their glutathione-dependent enzymes was carried out using the STRING, BioGrid, while Signor databases revealed interactions between such glioma markers as IDH and p53 and the glutathione exchange enzymes (glutathione peroxidase, glutathione reductase, glutathione S-transferase). The most pronounced relationship with glutathione metabolism was demonstrated by the level of the nuclear protein Ki67 as a marker of proliferative activity, and the presence of the IDH1 mutation as one of the key genetic events of gliomagenesis. The glutathione system is an active participant in the body’s antioxidant defense, involving the p53 markers and MGMT promoter methylation. It allows characterization of the gliomal cells’ status at different stages of tumor development.

В статье показана серия экспериментов, направленных на выявление наиболее неблагоприятного периода для патологического воздействия гипоксии при беременности и ее влияние на потомство. Разработан способ моделирования хронической гипобарической гипоксии у беременных самок мышей.В первой серии экспериментов моделирование ХГГ проводили на беременных самках в I, II, III триместрах беременности. Животных ежедневно в течение 7 дней помещали в гипобарическую барокамеру, в которой в течение 40 мин поддерживали давление 405–350 мм рт. ст., что соответствует высоте 5500-6000 м над уровнем моря.Во второй серии экспериментов моделирование ХГГ у беременных самок мышей проводили в I – II триместрах беременности (с 5 по 15 день гестации), создавая условия, соответствующие подъёму на высоту 6500-7000 м, на 30 минут в течение 10 дней.Контрольную группу в проведенных экспериментах составили беременные самки мышей без воздействия ХГГ.На 19 сутки гестации у беременных самок проводилось изъятие и оценка количества эмбрионов. Определяли росто-весовые характеристики эмбрионов и родившихся плодов, а также особенности постнатального развития потомства.В результате проведенных исследований было установлено, что наиболее чувствительными к воздействию хронической гипоксии является I и II триместр беременности. Воздействие гипоксии в эти сроки приводит к значительному снижению численности потомства (p<0,005) и весо-ростовых показателей новорождённых мышей при рождении (p<0,005) и на 3-е сутки жизни (p<0,005). The article shows a number of experiments aiming to identify the trimesters of pregnancy in which the embryo is most vulnerable to the adverse effects of hypoxic damage. A method for modeling chronic hypobaric hypoxia (CHH) in pregnant female mice has been developed. 2 series of experiments were carried out.​In the first set of experiments, CHH was modelled on pregnant females in first, second, and third trimesters of pregnancy. For 7 days in a row animals were placed daily in a hypobaric pressure chamber, in which a pressure of 405–350 mm Hg art. was maintained for 40 min., which is consisent with an altitude of 5500-6000 m above sea level.​In the second set of experiments, the modelling of CHG in pregnant female mice was conducted in I-II trimesters of pregnancy (from 5 to 15 days of gestation), creating conditions consistent with an ascent to an altitude of 6500-7000 m, for 30 minutes in 10 days.Control group in the conducted experiments consisted of pregnant female mice without CHG exposure.​On the 19th day of gestation, the embryos were removed from pregnant females and the number of embryos was assessed. Size and weight characteristics of embryos and born fetuses, as well as offspring features of the postnatal development were determined.As a result of the studies, it was found that I and II trimesters of pregnancy are the most susceptible to the effects of chronic hypoxia. Exposure to hypoxia during these periods leads to a significant decrease in the number of offspring (p <0.005) and weight and size parameters of newborn mice at birth (p <0.005) and on the 3rd day of life (p <0.005).

The purpose was to study the diagnostic value of the content of brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) in patients with meningiomas before and after surgery. Material and methods. The study involved 70 patients with meningiomas and 62 healthy people. The examination of the patients included clinical and neurological examination, determination of BDNF and GDNF (R&D Systems, USA) content in blood plasma using enzyme immunoassay performed before the surgery and 5–6 days after meningioma surgery. The totality of meningioma removal was determined intraoperatively, which was then confirmed by control neuroimaging a day after the operation. Results. BDNF level less than 2038,6 PG/ml allows diagnosing the characteristic of meningiomas changes with a sensitivity of 88% and a specificity of 44%. GDNF level more than 3.1 PG/ml allows diagnosing the meningioma-related changes in the brain with sensitivity of 84% and specificity of 51%. The plasma level of BDNF in patients after subtotal removal of meningioma on 5–6 days after surgery significantly increased, compared with the preoperative value, p = 0,01. The plasma concentration of GDNF in patients with meningiomas after radical removal of the tumor significantly decreased compared to its preoperative lever, p = 0,01. Conclusion. To summarize, our data show that none of the investigated markers is suitable to substitute histological diagnosis. However, measurement of circulating BDNF and GDNF before and after surgery may be a support to diagnose the totality of meningioma removal.

The aim of the study was to define the role of brain-derived and glial cell line-derived neurotrophic factors (BDNF and GDNF) in realization of compensative and adaptive mechanisms of a neonatal organism to hypoxia. Materials and Methods. The experiments in vivo have been carried out on pregnant C57BL/6 mice (n=36). Chronic hypobaric hypoxia has been modeled in different pregnancy trimesters. On gestation days E19-20, concentration of BDNF and GDNF in the blood of the pregnant females was determined by enzyme immunoassay. Further, the number of neonatal mice, their weight and body length parameters have been assessed. Parturient mothers (n= 88) and their newborn babies followed up at the Clinic of Obstetrics and Gynecology of Pavlov University took part in the clinical investigations. Concentration of BDNF, GDNF, neuron-specific enolase (NSE), and hypoxia-inducible factor (HIF-1 beta) in the fetal cord blood has been determined by ELISA. The obtained data were retrospectively compared with cardiotocography, dopplerometry, presence of meconium-stained amniotic fluid and the neonate state at birth, assessment according to the Apgar score, and the course of adaptation period. Results. Chronic hypobaric hypoxia in pregnant mice in trimester I and II resulted in the significant decrease of BDNF and GDNF level, decrease in the number of embryos, and in significant changes in weight/height characteristics of the newborn pups. According to the clinical observations, an increased expression of the neurotrophic factors BDNF, GDNF provides protection to a neonate even if hypoxia factors are present and realized. A low content of BDNF and GDNF was observed in the group of infants with a high risk of developing unfavorable hypoxic damaging effects. Conclusion. The protective role of BDNF and GDNF in the regulation of fetal homeostasis in chronic hypoxia has been established experimentally and clinically.

Activation of the cerebral erythropoietin system can be a promising strategy for the management of various neurodegenerative and neuropsychiatric diseases as it triggers neuroprotective mechanisms and improves cognitive functions. Lack of information about the possible neurotrophic effect of erythropoietin reduces the possibility of using the brain receptor for erythropoietin as a therapeutic target in neurodegenerative diseases associated with hypoxia and inflammation. The investigation aims to study the influence of the erythropoietin receptor agonist - carbamylated darbepoetin (CdEpo) - on the morphofunctional features of neuron-glia networks of primary hippocampal cultures in mice under normoxia. Materials and Methods. Primary hippocampal cell cultures dissociated from embryos (E18) of C57BL/6 mice were used to study the influence of erythropoietin receptor stimulation on the functional activity of hippocampal neuron-glia networks. The experiments were carried out on days 18-23 of culture development in vitro. CdEpo (100 ng/ml) action duration was 24 h. Functional changes were assessed based on the electrical and metabolic activity of cultured cells using patch-clamp techniques, multielectrode registration of bioelectric activity in neural networks and calcium imaging, respectively. The morphological features of primary hippocampal cell cultures were studied using transmission electron microscopy. Results. Treatment of primary hippocampal cell cultures with CdEpo during 24 h did not affect the frequency of spontaneous single action potentials, spontaneous burst activity of cells, the patterns of neuron action potentials (the amplitude of depolarization phase, threshold potential, the amplitude of hyperpolarization phase), membrane capacity. It did not affect the bioelectric parameters of neural network activity (the number of spikes in a network burst, network burst duration, and inter-burst interval), calcium activity of neurons and glial cells determined by the duration and frequency parameters of spontaneous calcium oscillations. At the ultrastructural level, the number of mature asymmetric synaptic contacts remained unchanged under the influence of CdEpo, but there was a morphogenesis of the internal structure of dendritic spines: the number of spines with endoplasmic reticulum and/or the spine apparatus inside increased, which was a unique phenomenon for a model of primary hippocampal culture. Conclusion. There was revealed no neurotropic effect of CdEpo on the model of primary hippocampal culture as reflected by bioelectric activity parameters of single neurons, neuronal networks, and astrocytic network activity evident in the parameters of intracellular calcium concentration changes (calcium oscillations) under normoxia conditions. However, CdEpo causes changes in the internal structure of dendritic spines in some neurons with the spine apparatus appearing in them. The absence of CdEpo effect on the functions of intact neurons and glia indicates the relative safety of using this molecule for therapeutic purposes as cytoprotection for the brain tissue.

At present, there exists a vital problem of studying pathophysiological mechanisms of acute poisoning and the developing intoxication syndrome caused by taking psychoactive substances by the users, e.g. cathinones, to stimulate pharmacologically the effect of ethyl alcohol. A number of compounds with a narcogenic potential and some medicinal preparations, e.g. imipramine, are referred to the class of synthetic cathinones. The aim of the investigation was to study the effect of ethyl alcohol on animal behavior and the activity of some enzymes of the liver and the antioxidant system in acute imipramine poisoning. Materials and Methods. 167 patients of the Toxicological Center with poisoning by synthetic psychoactive substances and ethyl alcohol as well as 70 Wistar rats participated in the study. The animals were divided into 4 groups: those who were injected with physiological solution, imipramine, ethanol, and imipramine in combination with ethanol. Orientation and exploratory behavior of the rats, the activity of the liver and antioxidant system enzymes have been investigated. Results. It has been established that in acute ethanol and imipramine poisoning, restoration of orientation and exploratory behavior of the rats occurs more rapidly, inhibition of the enzymatic activity of the liver (ethanol dehydrogenase, lactate dehydrogenase) and the antioxidant system is noted but to a less extent than in acute imipramine intoxication.

The aim of the investigation was to study the effect of glial cell line-derived neurotrophic factor (GDNF) on animals' resistance to cerebral-ischemia-induced damage. Materials and Methods. In vivo studies were carried out on C3H male mice weighing 18-40 g. Ischemia modeling was performed by bilateral irreversible occlusion of both carotid arteries. A neurological status as well as an orientative-exploratory behavior of experimental animals and their learning capability in the post-ischemic period were analyzed by using "Open field" and "Passive avoidance" tests. In addition, high-resolution respirometer Oxygraph-2k (Oroboros, Austria) was applied to study an oxygen uptake rate of brain mitochondria in ischemic conditions. Results. GDNF application in bilateral occlusion of carotid arteries was found to contribute to the neurological status recovery. Moreover, it normalizes oxygen uptake rate of mitochondria in the post-ischemic period. Conclusion. GDNF has a marked neuroprotective and antihypoxic effect under ischemia modeling in vivo.

Callosal axon guidance during cerebral cortex development is complicated and far from being fully understood. Previous work in our lab has shown that basic helix loop helix transcription factors Neurod2 and Neurod6 are essential regulators for the fasciculation and guidance of callosal axons. Here we use acallosal Neurod2/6 deficient mice as a model system to selectively study callosal axon pathfinding in vivo. We identify Efna4 as transcriptional target of Neurod2/6 in developing neocortex. In utero electroporation of Efna4 into neocortical pyramidal neurons of Neurod2/6 deficient embryos is sufficient to cell-autonomously rescue callosal axon fasciculation and migration along the normal callosal path towards the midsagittal plane. Mechanistically, Efna4 forms a co-receptor complex with Ntrk2 (TrkB) in reverse signaling, and hence regulate AKT cascades in vitro and in vivo via Ntrk2’s SHC-binding tyrosine. Co-electroporation of dominant negative Ntrk2 K571N or Ntrk2 Y515F completely abolishes the ability of Efna4 to rescue callosal axon guidance in Neurod2/6 deficient mice. We also show that the Eph receptors are abundantly expressed in the cortical plate and ventricular zone, but minimally expressed in the intermediated zone (IZ) of the cortex, while ephrinA ligands are largely present on the callosal axons in the IZ. In addition, reverse signaling from extracellular domain of EphA receptors to Efna4 leads to active axonal retraction in vivo. The complementary expression and repulsive interaction of EphA receptors and ephrinA ligands suggest a permissive channel for callosal axon navigation before midline crossing. Thus, ephrinA ligands coordinate fasciculate growth and guidance of callosal axons via interaction with Ntrk2 in cis and with EphA receptors in trans.