Abstract
The total number of oligodendrocytes decreases during the period of late senescence as in the unit area of pyramidal layer of the cortex, as well as the surrounding white matter. Besides, decrease in the number of oligodendrocytes is being performed at the expence of the decrease of newly created oligodendrocytes, defferenciating cells and the number of already differentiated adult cells realizing the specific functions. The physiological death of neurocytes during the late senescence is accompanied by the physiologicsl death and loss of anatomically and functionally related oligodendrocytes, resulted in an increase of share of the apoptotic cells in the total number of oligodendrocytes. The fact that all types of cells including apoptocic cells in the old organisms are smaller in size –is expression of gerogenic changes. During apoptosis of smaller cells, aging cells undergo fragmentation into smaller parts in comparison of the relatively large size cells of young organisms. Thus, apoptosis in aging body has its gerogenic characteristics.
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