Comparative characteristics of the response of phylogenetically different areas of the brain to low doses of ionizing radiation

Abstract

Despite the considerable interest in low doses of ionizing radiation, the available literature data on the effect on the central nervous system are scarce and contradictory. Indicators of metabolic changes in the brain are indicators of the activity of succinate dehydrogenase (SDH), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-FDG). The purpose of our work was to reveal the ratio of the activity of aerobic and anaerobic pathways of bioenergetic metabolism of changes in the histometabolic profile under the action of small doses of radiation on various parts of the cerebral cortex and components of the striopallidal system. Materials and methods. The experiment was carried out on 60 white outbred male rats subjected to a single total gamma irradiation at a dose of 0.5 Gy. The sampling of the material was carried out after 1 day, 6 months, 1 g, 1.5 g after exposure. Determination of the activity of dehydrogenases was carried out on cryostat sections by tetrazolium reductase techniques using the salt nitro-CT in the neocortex (NC) - superior frontal gyrus (VLI) (Fr²); anterior limbic region (PLO) (Cg³); old cortex (SC) - hippocampal zones CA1-CA4, dentate fascia (DF); ancient cortex (DC) - piriform zone (PZ); ball pallid (BS) of the lenticular nucleus and in the caudate nucleus (CA). Studies in the indicated areas of the brain were carried out after microphotography of objects with subsequent morphometry and assessment of the content of the reaction product in histological preparations using an optical system, which included a Mikmed-1 microscope with a built in monochrome Panasonic DMC-FX3 camera, an adapter connected to a computer and the program Video-Test-Morpho. As a result of the study, it was revealed that the leading role in ensuring the function of various parts of the cerebral cortex and components of the striopallidal system after gamma irradiation at a dose of 0.5 Gy belongs to the mobilization of the pentose phosphate pathway of carbohydrate conversion. The degree of changes and the time of compensatory processes in the histoenzymological profile of the studied areas depends on the phylogenetic age of the studied structure of the brain.