[Characteristics of the wall of the 3d cerebral ventricle in rats from the viewpoint of age].

The results of the light-, electron microscopic and cytophotometric investigation performed in the wall of the third cerebral ventricle are presented. It includes the ciliar, tanycytar ependyma and subependymal layer in male rats of three age groups (immature--1 month, mature--8-10 months and old--24-26 months of age). A certain decrease in the arrangement density of cellular elements of the ventricular wall is noted with age. A depressed functional activity of the ciliar ependymocytes is revealed with ageing. At the same time, some compensatory-adaptive rearrangements develop; they counteract age decrease of the function. A suggestion is made that the drenage function of the ciliar ependymal area is disturbed with age. Specific age features of the ultrastructure of the blood capillaries situating subependymally are revealed. The age changes of ependymocytes and tanicytes, as well as those of certain groups of tanycytes are not unitypical; this speaks in favour of their different functional role.