SEX HORMONES PARTICI-PATION IN THE PATHOGE-NETIC MECHANISMS OF ALZHEIMER'S DISEASE

In scientific works of recent years increasing attention is paid to the influence of sex hormones on behavioral reactions, and mental activity. There is a lot of evidence that sex hormones are actively involved in the processes of neurogenesis, synaptogenesis, affecting the energy balance of neurons by regulating the functions of mitochondria. The higher incidence of Alzheimer's (AD) in women during menopause causes scientists to think about the influence of sex hormones on the development of neurodegenerative diseases. In this literature review, we set the goal to analyze the influence of sex hormones on the function and morphology of different brain sections, and especially those structures undergoing neurodegenerative changes during the development of AD. Main part. Alzheimer's Disease is the cause of significant cytoarchitectonic changes in brain structures that are responsible for cognitive function. Different structures vary in different ways in the process of aging and AD, which allows for predicting various pathogenetic mechanisms. AD primarily affects the nerve cells of the temporal lobe of the cerebral cortex and the hypocampus, which are responsible for the transmission of information and consolidation of memory. Damage to frontal lobes are responsible for making decisions, movement, language; parietal lobe that controls language, tactile sensations, spatial and temporal sensations, and tonsils responsible for emotional control. At AD in all of these structures, amyloid plaques and neurofibrillary tangles accumulate. One of the mechanisms of neuroprotective action of estrogens is the reduction of amyloid accumulation. Neurogenesis in the adult brain is active in the nucleus of the hypocampus and subventricular zone. It is significantly reduced after ovariectomy and is restored after the introduction of estradiol. It was believed that steroid hormones are synthesized only in the ovaries and affect the processes of transcription, but it turned out that these hormones are synthesized and in neural chains where they quickly, in minutes, modulate behavioral reactions and regulate spatial memory. The age-related decrease in the concentration of sex hormones is the cause of various neuroendocrine changes, and is manifested by a decrease in brain volumes, a decrease in the size of the neurons, the number of dendrites, an increase in apoptosis, neurodegenerative processes, manifested by a change in behavioral responses. The main mechanism of action of sex hormones is to bind to free highly specific and accessible intracellular receptors of these hormones and to influence the processes of transcription. Conclusions. An overview of literary sources, which took the decade has shown that in recent years medical science has proven that endogenous estrogens and their receptors play an important role not only in the reproductive system. Estrogens act as powerful neuroprotectors, and scientists, and their clinicians consider estrogens as possible medications for neurodegenerative diseases and acute brain damage (stroke, trauma) not only in women, but also in men. The literature review highlighted new data on the influence of estrogens on cerebral blood flow, hormonal effects on mitochondrial function and energy supply. Many questions require a further study, but it is understandable that when choosing strategies and tactics for the treatment of neurological patients, it is necessary to take into account the effects of neurosteroids on CNS structures.