FORENSIC MEDICAL ASPECTS OF DETERMINING THE DURATION OF INJURY DEVELOPMENT

Аннотация

The presented analytical review of literature addresses the state of the study of the morphology of microglia, astrocytes, oligodendrocytes, and the blood-brain barrier in suicide. According to the generalized data, the most characteristic localization of changes in the development of suicidal behavior was determined by the suture nucleus, prefrontal and anterior cingulate cortex. There is evidence of a correlation between the development of suicidal behavior and an increase in inflammatory cytokines in the prefrontal cortex, disruption of the connection between astrocytes and oligodendrocytes in the anterior cingulate cortex, as well as indication of involvement in the process of forming suicidal behavior of the cortex, striatum, preclinium and cuneiform, orbitofrontal cortex. Keywords: microglia; astrocytes; oligodendrocytes; suicide; morphology. Management Suicide ― death resulting from a certain behavior aimed at causing harm to oneself. Every year, about 703 thousand people in the world commit suicide. According to the World Health Organization, the main risk group for the development of suicidal behavior is young people under 49 years old, and in the 14-19 age group, this reason is fourth in importance. The most significant risk factor is the presence of previous unfinished attempts in the medical history. The main reason for the development of suicidal behavior is considered to be major depressive disorder, but not every depressive episode leads to incomplete suicide attempts or suicide. The pathophysiology of depression, and consequently, suicide, still remains the focus of specialists' attention due to the diversity of forms, etiological factors, and comorbidity with other psychopathological syndromes. However, the results of recent studies demonstrate functional and morphological changes in certain areas of the brain leading to the development of depressive disorder, including the issues of changes and influences of the microenvironment on the functional activity of neurons and their relationship with the development of certain mental disorders. 23 https://universalpublishings.com МЕДИЦИНА, ПЕДАГОГИКА И ТЕХНОЛОГИЯ: ТЕОРИЯ И ПРАКТИКА Researchbib Impact factor: 13.14/2024 SJIF 2024 = 5.444 Том 3, Выпуск 07, Июль In this review, we examined the main changes identified in astrocytes, oligodendrocytes, microglia, and the blood-brain barrier in completed suicide at this time. The listed cells are of particular interest, as they perform numerous functions responsible for the normal functioning and vital activity of neurons, and consequently, for a person's cognitive abilities and emotional state. These are primary immune cells of the central nervous system, having certain similarities with macrophages in their functions. Despite this, microglia cells do not have a monocytic origin, but are secreted from the yolk sac during embryogenesis, and in adulthood, their population is maintained through self-renewal. There are studies demonstrating different immunohistochemical expressions of CD39 and CD45 by microglia and monocytic macrophages. Specific immunohistochemical markers for microglia are HAM-56 and CD68. Under the influence of external (trauma, infectious diseases) or internal (stress) factors, the microglia can be activated, thereby promoting the release of pro- inflammatory cytokines and neurotransmitters, triggering the processes of damage and premature death of neurons. As a result of activation, there is also an increase in the production of quinoline acid (QUIN) ― a toxic product and agonist of N-methyl-D- aspartic acid (NMDA) receptors, the level of which increases and correlates with the development of suicidal behavior. QUIN formation occurs through the kinurenin pathway of tryptophan metabolism, which, in turn, leads to a decrease in serotonin production and its deficiency. In addition to serotonin, there is a decrease in kinurenic acid (KYNA) - NMDA antagonist, which suppresses glutamate neurotransmission. On the other hand, activation leads to an increase in the content of interleukins, which causes the loss of inhibition in glutamatergic neurons and an increase in the release of glutamate. In studies, microglia activation was detected in the postmortem brain material of patients with psychiatric illnesses who committed suicide and in the control group of people who died non-violent death. Larger and rounder cells with branched processes were identified using the immunohistochemical marker ― HLA-DR-antigen ― in the suture nucleus. In other studies, microglia activation in the prefrontal and anterior cingulate cortex in the brain material of people suffering from major depressive syndrome with completed suicide was detected, compared to the control group with sudden death, where no such changes were found. Astrocytes are multifunctional glial cells whose role is to maintain and regulate the nutrition and metabolism of neurons, as well as to synthesize growth factors and maintain the blood- 2