Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.

The aim of the study was to study the effect of TrkB-mediated action of the brain-derived neurotrophic factor (BDNF) on animal survival and mitochondrial respiratory chain activity in acute hypobaric hypoxia model in vivo. Materials and Methods. In vivo experiments were performed on mature male CBA mice weighing 20-25 g. In order to modulate acute hypobaric hypoxia, the animals were placed in the hypobaric chamber (220-240 mm Hg) which simulates conditions corresponding to the altitude of 10 000 m above sea level. The oxygen consumption rate by the brain mitochondria under the hypoxic influence was evaluated using a high-resolution OROBOROS Oxygraph-2k respirometer (OROBOROS Instruments, Austria). Results. Preventive BDNF application has been established to increase the survival of the CBA-line animals after acute hypobaric hypoxia modeling and to influence favorably the work of mitochondrial respiratory chain complex I. Conclusion. BDNF increases animal resistance to acute hypobaric hypoxia and influences the work of mitochondrial respiratory chain through TrkB-signaling mechanisms. Antihypoxic effect of BDNF is realized by maintaining the activity of NADH-dependent pathway of substrate oxidation and ATP synthesis.

The aim of the investigation was to study the effect of chronic and acute prenatal hypoxia on the parameters of CNS functional activity and to assess the role of mitochondria in the protection of the CNS against experimental hypoxic influence in vivo. Materials and Methods. The experiments in vivo were performed on C57BL/6 mice. In order to model chronic prenatal hypoxia, pregnant female mice were placed daily into a hypobaric chamber beginning with the fourteenth day of gestation up to delivery. 280-300 mm Hg pressure corresponding to the altitude of 8000 m above sea level was maintained in the chamber for 2 h. Acute prenatal hypoxia was modeled on the eighteenth day of gestation. Pregnant females were placed for 4-5 min (till the first agonal breath) in the hypobaric chamber under 220-240 mm Hg pressure corresponding to the altitude of 10,000 m above sea level. Oxygen consumption rate by mice brain mitochondria was assessed on the first day of the post-natal period using a high-resolution Oxygraph-2k respirometer (Oroboros Instruments, Austria). To determine a general state of the CNS in the remote post-hypoxic period, a neurological status of the 4-week-old animals was evaluated according to the neurological deficit scale for small laboratory animals and Garcia's scale. Mnestic and cognitive abilities were also tested in Morris water maze. Results. Protocols of acute and chronic prenatal hypoxia modeling for mice have been designed. Acute hypoxic damage has been shown to result in the significant decrease of the basal oxygen consumption rate and intensity of oxidative phosphorylation by the brain

Currently, the role of the neurotrophic factors BDNF and GDNF in maintaining the brain’s resistance to the damaging effects of hypoxia and functional recovery of neural networks after exposure to damaging factors are actively studied. The assessment of the effect of an increase in the level of these neurotrophic factors in brain tissues using genetic engineering methods on the resistance of laboratory animals to hypoxia may pave the way for the future clinical use of neurotrophic factors BDNF and GDNF in the treatment of hypoxic damage. This study aimed to evaluate the antihypoxic and neuroprotective properties of BDNF and GDNF expression level increase using adeno-associated viral vectors in modeling hypoxia in vivo. To achieve overexpression of neurotrophic factors in the central nervous system’s cells, viral constructs were injected into the brain ventricles of newborn male C57Bl6 (P0) mice. Acute hypobaric hypoxia was modeled on the 30th day after the injection of viral vectors. Survival, cognitive, and mnestic functions in the late post-hypoxic period were tested. Evaluation of growth and weight characteristics and the neurological status of animals showed that the overexpression of neurotrophic factors does not affect the development of mice. It was found that the use of adeno-associated viral vectors increased the survival rate of male mice under hypoxic conditions. The present study indicates that the neurotrophic factors’ overexpression, induced by the specially developed viral constructs carrying the BDNF and GDNF genes, is a prospective neuroprotection method, increasing the survival rate of animals after hypoxic injury.

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.Key words: glial cell line-derived neurotrophic factor; GDNF; neuroprotection; cerebral ischemia. During several years the number of ischemic brain injury incidents has been dramatically increased, that determines topical and socially important issue for modern neurology and neuroscience. The consequences of cerebral ischemia are directly related to memory and neurological status deteriorations as well as to impairment of learning capabilities and cognitive functions. Therefore, the development of modern techniques to effectively protect the nervous system from those damaging effects is urgently needed. A promising approach to improve adaptive capabilities of nervous system supposed to the activation of endogenous systems promoting the survival of nervous cells under stress factors and maintenance their functional activity. The use of neurotrophic factors such as glial cell linederived neurotrophic factor (GDNF) is of special interest. These proteins are attracted of scientists' attention because of their possibilities to regulate neurogenesis and the functioning of the nervous cells not only in early ontogenesis, but also in an adult brain. Moreover, they are involved in the processes of synapses formation, and have a pronounced effect on growth Biomedical investigations