[Ultrastructural characteristics of the capillary basement membrane of the cerebral cortex in normal state and in severe focal diseases].

The capillary basal membranes of the cerebral cortex in adult rats and man have similarultrastructure in normality. The same formation of capillaries of the cerebral cortex of 1 day old rats is characterized by a not uniform structure and relatively low electron-optical density. The capillary basal membrane of the cortex of patients not older than 30 with severe focal lesions of the brain has increased thickness in some portions where it iscomposed of a homogenous substance, osmophilic granules, light cavities of different size and shape, vesicles restricted with a sheath and rare dense bodies. In elderly patients older that 40 the capillary basal membrane in thicker zones appears to be more electron dense and homogeneous than in younger patients.