ELECTRONMICROSCOPIC FEATURES OF STRUCTURAL ELEMENTS IN THE BRAIN MENINGS OF WHITE RATS

Abstract

The aim of the work was to study the electron microscopic features of the structure of cellular and fibrillar elements in brain meninges of white rats. The main focus was on clarifying the relationship between cells that make up the barrier cell layer of the arachnoid (BCAL), and the so-called dural border cell layer (DBCL). Araldite-Epone blocks adopted in electron microscopy were made from fragments of the cerebral cortex and meninges taken from white rat. Subsequently, ultrathin sections were obtained using a Leica EM UC7 ultratome (Germany). After staining, the sections were examined with an electron microscope (JEM-1400-Japan) and photographed. Ultrastructurally, only cellular and fibrillar elements characteristic of connective tissue were revealed in the composition of the dura mater. Electron micrographs demonstrate that in leptomeninx as a result of a high degree of heterochromatin condensation in the nucleus and the nucleolus in the central part and the predominance of cytoskeleton elements in the peripheral part of cellular elements, the cells darken as they approach the BCDM. The presence of communicating, desmosomal and especially tight junctions between cells of so-called BCDM, which are the morphological indicators of the arachnoid barrier, shows that it is part of leptomeninx. The detection of the accumulation of cytoskeleton elements, the condensation of chromatin in nucleus, the presence of only individual ribosomes and mitochondria with destroyed cristae starting from the first layer, as well as the absence of a nucleus in the cells of the surface layer can be seen and identified as signs of keratinization in cells of BCAL which have the epithelial structure.