[Changes in the subcommissural organ of white rats with age].

Histological and histochemical methods were applied to the study of 82 male rats of different age (newborn, 1-, 2-, 5-, and 17-month-old). Microstructure of the subcomissural organ (SCO) was investigated; the height of its ependyma was measured. In rats at all the age groups studied ependymocytes secreted substances of glucoproteid nature; a moderate content of RNA persisted in the cells, and also a high activity of non-specific esterases. Secretory activity of ependymocytes increased with the growth of the animals, remaining high in adult rats; it fell in the old animals. Age changes of the SCO consisted in the reduction of the height of the ependyma, of the number of cell layers in it and atrophy of the villi.