EN
Currently the structure and function of oligodendrocytes in the central nervous system (cns) in young individuals is known; however, there is no information about their morphology in the central gray matter (substantia grisea centralis-SGC) in old animals. The aim of this study was to investigate the morphology of oligodendrocytes in the semithin SGC sections of 6-month (5 pcs) and 3-year-old (5 pcs) male Wistar rats. The animals were anaesthetized with ketamine, perfused with fixative through the left ventricle, and the midbrains containing SGC were taken. Semithin sections were analyzed morphologically and photographs were made in light microscope Axiolab (Zeiss). In the semithin sections of the SGC of 6-month-old adult rats oligodendrocytes with mostly light and medium density cytoplasm were observed. Oligodendrocytes were located by different structures: blood vessels, neurons and astrocytes. Sometimes two cells with dark cytoplasm were side by side or near oligodendrocytes with a medium cytoplasm density. In old male rats oligodendrocytes with dark cytoplasm located at the capillary blood vessels, neurons and astrocytes were dominant in the SGC. Cells with light cytoplasm, which occurred mainly in blood vessels, were rarely encountered. The results indicate that in the SGC of 3-years-old individuals older forms with a dark cytoplasm are dominant, in contrast to 6-month-old rats which have younger oligodendrocytes with light cytoplasm.